Friedrich HA24K25L User Manual
S e r v i c e M a n u a l – R 4 1 0 A Models  
A Series (Electronic Controls)  
Single Package Vertical Air Conditioning System  
L Suffix Models  
V(E, H)A09K25L-*  
V(E, H)A12K25L-*  
V(E, H)A18K25L-*  
V(E, H)A24K25L-*  
V(E, H)A24K75L-*  
V(E, H)A09K34L-*  
V(E, H)A12K34L-*  
V(E, H)A18K34L-*  
V(E, H)A24K34L-*  
V(E, H)A24K10L-*  
V(E, H)A09K50L-*  
V(E, H)A12K50L-*  
V(E, H)A18K25L-*  
V(E, H)A24K50L-*  
VPK-ServMan-L (1-10)  
*Last Digit May Vary  
Table of Contents  
Important Safety Information ........................................... 2-4  
Capillary Tube Systems/Check Valve ..........................24  
Reversing Valve — Description/Operation .................. 25  
Testing Coil .................................................................. 25  
Checking Reversing Valves ....................................25-26  
Introduction .........................................................................4  
Vert-I-Pak Model Number Identification Guide ................... 5  
Serial Number Identification Guide .................................... 5  
Chassis Specifications ....................................................... 6  
Extended Cooling Performance ......................................... 7  
Electrical Requirements ..................................................... 8  
Remote Thermostat and Low Voltage Control .............. 9-10  
V-PAK Electronic Control Board Features ........................ 11  
Electronic Control Configuration .......................................12  
Reversing Valve  
Touch Testing Heating/Cooling Cycle ......................... 26  
Procedure For Changing Reversing Valve ............. 26-27  
Compressor Checks .................................................... 27  
Locked Rotor Voltage Test .......................................... 27  
Single Phase Connections ......................................... 27  
Determine Locked Rotor Voltage ............................... 27  
Locked Rotor Amperage Test ...................................... 27  
Single Phase Running & Locked Rotor Amperage ..... 27  
Checking the Overload ...........................................27-28  
External Overload ........................................................28  
Compressor Single Phase Resistance Test ................ 28  
Compressor Replacement ..................................... 29-30  
Routine Maintenance ...................................................30  
9-18 Electrical Troubleshooting Chart – Cooling ......... 31  
2-Ton Electrical Troubleshooting Chart – Cooling ....... 32  
Electrical Troubleshooting Chart – Heat Pump ........... 33  
Refrigerant System Diagnosis – Cooling .................... 34  
Refrigerant System Diagnosis – Heating .................... 34  
Electrical and Thermostat Wiring Diagrams ........... 35-40  
Technical Service Data ................................................ 41  
Electronic Control Error Code  
Diagnostics/Test Mode .................................................12-13  
Electronic Control Features .............................................. 14  
Checking External Static Pressure ................................... 15  
Checking Approximate Airflow .......................................... 16  
Airflow Charts ....................................................................16  
Components Testing ....................................................17-18  
Refrigeration Sequence of Operation ............................... 19  
Service ............................................................................. 20  
Sealed Refrigeration System Repairs .............................. 21  
Refrigerant Charging ........................................................ 21  
Method Of Charging ......................................................... 22  
Undercharged Refrigerant Systems ............................ 22-23  
Overcharged Refrigerant Systems ................................... 23  
Restricted Refrigerant Systems ....................................... 23  
1
IMPORTANT SAFETY INFORMATION  
The information contained in this manual is intended for use by a qualified service technician who is familiar  
with the safety procedures required for installation and repair, and who is equipped with the proper tools and  
test instruments required to service this product.  
Installation or repairs made by unqualified persons can result in subjecting the unqualified person making  
such repairs as well as the persons being served by the equipment to hazards resulting in injury or electrical  
shock which can be serious or even fatal.  
Safety warnings have been placed throughout this manual to alert you to potential hazards that may be  
encountered. If you install or perform service on equipment, it is your responsibility to read and obey these  
warnings to guard against any bodily injury or property damage which may result to you or others.  
Your safety and the safety of others are very important.  
We have provided many important safety messages in this manual and on your appliance. Always read  
and obey all safety messages.  
This is a safety Alert symbol.  
This symbol alerts you to potential hazards that can kill or hurt you and others.  
All safety messages will follow the safety alert symbol with the word “WARNING”  
or “CAUTION”. These words mean:  
You can be killed or seriously injured if you do not follow instructions.  
WARNING  
You can receive minor or moderate injury if you do not follow instructions.  
CAUTION  
All safety messages will tell you what the potential hazard is, tell you how to reduce the chance of injury,  
and tell you what will happen if the instructions are not followed.  
A message to alert you of potential property damage will have the  
word “NOTICE”. Potential property damage can occur if instructions  
are not followed.  
NOTICE  
PERSONAL INJURY OR DEATH HAZARDS  
ELECTRICAL HAZARDS:  
•
Unplug and/or disconnect all electrical power to the unit before performing inspections,  
maintenance, or service.  
•
•
•
Make sure to follow proper lockout/tag out procedures.  
Always work in the company of a qualified assistant if possible.  
Capacitors, even when disconnected from the electrical power source, retain an electrical charge  
potential capable of causing electric shock or electrocution.  
•
•
Handle, discharge, and test capacitors according to safe, established, standards, and approved  
procedures.  
Extreme care, proper judgment, and safety procedures must be exercised if it becomes necessary  
to test or troubleshoot equipment with the power on to the unit.  
2
•
•
Do not spray or pour water on the return air grille, discharge air grille, evaporator coil, control panel,  
and sleeve on the room side of the air conditioning unit while cleaning.  
Electrical component malfunction caused by water could result in electric shock or other electrically  
unsafe conditions when the power is restored and the unit is turned on, even after the exterior is dry.  
•
•
•
•
•
•
•
Never operate the A/C unit with wet hands.  
Use air conditioner on a single dedicated circuit within the specified amperage rating.  
Use on a properly grounded outlet only.  
Do not remove ground prong of plug.  
Do not cut or modify the power supply cord.  
Do not use extension cords with the unit.  
Follow all safety precautions and use proper and adequate protective safety aids such as: gloves,  
goggles, clothing, adequately insulated tools, and testing equipment etc.  
•
Failure to follow proper safety procedures and/or these warnings can result in serious injury or death.  
REFRIGERATION SYSTEM HAZARDS:  
•
•
•
Use approved standard refrigerant recovering procedures and equipment to relieve pressure before  
opening system for repair.  
Do not allow liquid refrigerant to contact skin. Direct contact with liquid refrigerant can result in minor  
to moderate injury.  
Be extremely careful when using an oxy-acetylene torch. Direct contact with the torch’s flame or hot  
surfaces can cause serious burns.  
•
•
•
Make sure to protect personal and surrounding property with fire proof materials.  
Have a fire extinguisher at hand while using a torch.  
Provide adequate ventilation to vent off toxic fumes, and work with a qualified assistant whenever  
possible.  
•
•
•
Always use a pressure regulator when using dry nitrogen to test the sealed refrigeration system for  
leaks, flushing etc.  
Make sure to follow all safety precautions and to use proper protective safety aids such as: gloves,  
safety glasses, clothing etc.  
Failure to follow proper safety procedures and/or these warnings can result in serious injury or death.  
MECHANICAL HAZARDS:  
•
Extreme care, proper judgment and all safety procedures must be followed when testing,  
troubleshooting, handling, or working around unit with moving and/or rotating parts.  
•
Be careful when, handling and working around exposed edges and corners of sleeve, chassis, and  
other unit components especially the sharp fins of the indoor and outdoor coils.  
•
•
Use proper and adequate protective aids such as: gloves, clothing, safety glasses etc.  
Failure to follow proper safety procedures and/or these warnings can result in serious injury or death.  
3
PROPERTY DAMAGE HAZARDS  
FIRE DAMAGE HAZARDS:  
•
•
•
•
•
•
•
Read the Installation/Operation Manual for this air conditioning unit prior to operating.  
Use air conditioner on a single dedicated circuit within the specified amperage rating.  
Connect to a properly grounded outlet only.  
Do not remove ground prong of plug.  
Do not cut or modify the power supply cord.  
Do not use extension cords with the unit.  
Failure to follow these instructions can result in fire and minor to serious property damage.  
WATER DAMAGE HAZARDS:  
•
Improper installation maintenance, or servicing of the air conditioner unit, or not following the above  
Safety Warnings can result in water damage to personal items or property.  
•
•
•
Insure that the unit has a sufficient pitch to the outside to allow water to drain from the unit.  
Do not drill holes in the bottom of the drain pan or the underside of the unit.  
Failure to follow these instructions can result in result in damage to the unit and/or minor to serious  
property damage.  
4
Model Identification Guide  
MODEL NUMBER  
V
E
A
24 K 50 RT L  
SERIES  
V=Vertical Series  
ENGINEERING CODE  
E=Cooling with or without electric heat  
H=Heat Pump  
OPTIONS  
RT = Standard Remote Operation  
d  
DESIGN SERIES  
A = 32" and 47" Cabinet  
NOMINAL CAPACITY  
A-Series (Btu/h)  
09 = 9,000  
ELECTRIC HEATER SIZE  
A-Series  
00 = No electric heat  
25 = 2.5 KW  
12 = 12,000  
18 = 18,000  
34 = 3.4 KW  
24 = 24,000  
50 = 5.0 KW  
75 = 7.5 KW  
10 = 10 KW  
VOLTAGE  
K = 208/230V-1Ph-60Hz  
VPAK Serial Number Identification Guide  
SERIAL NUMBER  
A
K
A
N
00001  
YEAR MANUFACTURED  
PRODUCTION RUN NUMBER  
LJ = 2009 AE = 2015  
AK = 2010 AF = 2016  
AA = 2011 AG = 2017  
AB = 2012 AH = 2018  
AC = 2013 AJ = 2019  
AD = 2014  
PRODUCT LINE  
N = VPAK  
MONTH MANUFACTURED  
A = Jan  
B = Feb  
C = Mar  
D = Apr  
E = May  
F = Jun  
G = Jul  
H = Aug  
J = Sep  
K = Oct  
L = Nov  
M = Dec  
5
Chassis Specifications  
Model 2010  
COOLING DATA  
VEA09K VEA12K VEA18K VEA24K  
VHA09K VHA12K VHA18K VHA24K  
COOLING BTUh  
POWER (W)  
EER  
9400/9000 11500/11200 17000/16500 23000/22700  
9200/9000 11500/11200 17000/16800 23000/22800  
959  
9.8/9.8  
0.74  
1173  
9.8/9.8  
0.72  
1888  
9.0/9.0  
0.70  
2421  
9.5/9.5  
0.70  
939  
9.8/9.8  
0.74  
1186  
9.7/9.7  
0.72  
1868  
9.1/9.1  
0.70  
2527  
9.1/9.1  
0.70  
SENSIBLE HEAT RATIO  
HEAT PUMP DATA  
HEATING BTUh  
COP @ 47F  
N/A  
N/A  
N/A  
N/A  
8500  
3.0  
10800  
3.0  
16000  
3.0  
20000  
3.0  
HEATING POWER (W)  
830  
3.6  
1055  
4.9  
1563  
7.5  
1953  
9.4  
HEATING CURRENT (A)  
ELECTRICAL DATA  
VOLTAGE (1 PHASE, 60 Hz)  
VOLT RANGE  
230/208  
253-198  
4.2/4.4  
19.8  
230/208  
253-198  
5.2/5.4  
30  
230/208  
253-198  
8.1/8.5  
42  
230/208  
253-198  
10.0/10.4  
34.8  
230/208  
253-198  
4.1/4.3  
18.5  
230/208  
253-198  
5.3/5.5  
26  
230/208  
253-198  
8.2/8.5  
42  
230/208  
253-198  
10.6/10.8  
34.8  
COOLING CURRENT (A)  
AMPS L.R.  
AMPS F.L.  
3.5  
4.5  
7.8  
9.5  
3.5  
5
7.8  
9.5  
INDOOR MOTOR (HP)  
INDOOR MOTOR (A)  
OUTDOOR MOTOR (HP)  
1/4  
1/4  
1/4  
1/4  
1/4  
1/4  
1/4  
1/4  
1.2  
1.2  
1.2  
1.94  
1.2  
1.2  
1.2  
1.94  
N/A  
1/4  
N/A  
1/4  
OUTDOOR MOTOR (A)  
N/A  
0.85  
N/A  
0.85  
AIRFLOW DATA  
INDOOR CFM*  
VENT CFM  
300  
60  
350  
60  
450  
60  
610  
60  
300  
60  
420  
60  
450  
60  
610  
60  
MAX. ESP  
.3"  
.3"  
.3"  
.4"  
.3"  
.3"  
.3"  
.4"  
PHYSICAL  
DIMENSIONS (W x D x H)  
NET WEIGHT (LBS)  
23x23x32  
114  
23x23x32  
124  
23x23x32  
144  
23x23x47  
167  
23x23x32  
114  
23x23x32  
125  
23x23x32  
144  
23x23x47  
167  
SHIPPING WEIGHT (LBS)  
R410A CHARGE (oz)  
125  
135  
155  
220  
125  
135  
155  
220  
33.5  
35.5  
48  
65  
39  
42  
52  
74  
* Normal Value Wet Coil @ .1"ESP.  
ELECTRIC HEAT DATA  
VE/VHA09  
VE/VHA12  
HEATER WATTS  
2500/2050 3400/2780 5000/4090 2500/2050 3400/2780 5000/4090  
230/208 230/208  
8500/7000 11600/9500 17000/13900 8500/7000 11600/9500 17000/13900  
VOLTAGE  
HEATING BTUh  
HEATING CURRENT (AMPS)  
MINIMUM CIRCUIT AMPACITY  
BRANCH CIRCUIT FUSE (AMPS)  
BASIC HEATER SIZE  
10.9/9.9  
15  
15  
2.5 Kw  
14.8/13.4  
19.9  
20  
3.4 Kw  
21.7/19.7  
28.6  
30  
5.0 Kw  
10.9/9.9  
15  
15  
2.5 Kw  
14.8/13.4  
19.9  
20  
3.4 Kw  
21.7/19.7  
28.6  
30  
5.0 Kw  
ELECTRIC HEAT DATA  
VE/VHA18  
VE/VHA24  
HEATER WATTS  
2500/2050 3400/2780 5000/4090 2500/2050 3400/2780 5000/4090 7500/6135 10000/8180  
230/208 230/208  
8500/7000 11600/9500 17000/13900 8500/7000 11600/9500 17000/1390025598/2093934130/27918  
VOLTAGE  
HEATING BTUh  
HEATING CURRENT (AMPS)  
MINIMUM CIRCUIT AMPACITY  
BRANCH CIRCUIT FUSE (AMPS)  
BASIC HEATER SIZE  
10.9/9.9  
15  
15  
2.5 Kw  
14.8/13.4  
19.9  
20  
3.4 Kw  
21.7/19.7  
28.6  
30  
5.0 Kw  
10.9/9.9  
17.2/15.9  
25  
14.8/13.4  
22.1/20.3  
25  
21.7/19.7  
30.7/28.1  
30  
32.6/29.5  
44.3/40.3  
45  
43.5/39.3  
57.9/52.7  
60  
2.5 Kw  
3.4 Kw  
5.0 Kw  
7.5 Kw  
10.0 Kw  
6
Extended Cooling Performance  
VEA - EXTENDED COOLING PERFORMANCE  
OUTDOOR DRY BULB TEMP. (DEGREES F AT 40% R.H.)  
85 95 105  
INDOOR WET BULB TEMP. (DEGREES F AT 80 F D.B.)  
67 62 72 67 62 72 67  
75  
67  
110  
67  
72  
62  
72  
62  
72  
62  
BTUh  
WATTS  
AMPS  
SHR  
BTUh  
WATTS  
AMPS  
SHR  
BTUh  
WATTS  
AMPS  
SHR  
BTUh  
WATTS  
AMPS  
SHR  
11054 10631 9842 10528 9926 9156 10114 9400 8319 9475 8413 7417 8954 7835 6914  
783  
3.5  
0.51  
795  
3.5  
0.69  
804  
3.5  
0.93  
853  
3.7  
0.52  
861  
3.8  
0.71  
872  
3.8  
0.95  
959  
4.2  
0.52  
959  
4.20  
0.74  
959  
4.2  
0.95  
1037 1036 1039 1084 1083 1087  
VEA09  
VEA12  
VEA18  
VEA24  
4.5  
4.5  
4.5  
4.7  
4.7  
4.7  
0.53  
0.78  
0.96  
0.55  
0.81  
0.95  
13524 13007 12041 12880 12144 11201 12374 11500 10178 11592 10293 9074 10954 9585 8458  
957  
4.3  
0.49  
972  
4.3  
0.67  
983  
4.4  
0.90  
1043 1053 1066 1173 1173 1173 1268 1267 1270 1325 1325 1330  
4.6  
4.7  
4.7  
5.2  
5.20  
0.72  
5.2  
5.6  
5.6  
5.6  
5.9  
5.9  
5.9  
0.50  
0.70  
0.92  
0.51  
0.92  
0.52  
0.76  
0.93  
0.53  
0.79  
0.93  
19992 19227 17799 19040 17952 16558 18292 17000 15045 17136 15215 13413 16193 14170 12504  
1541 1565 1582 1678 1695 1716 1888 1888 1888 2041 2039 2045 2133 2132 2140  
6.7  
0.48  
6.7  
0.65  
6.8  
0.88  
7.2  
0.49  
7.2  
0.68  
7.3  
0.89  
8.1  
0.49  
8.10  
0.70  
8.1  
0.90  
8.7  
0.50  
8.7  
0.74  
8.7  
0.90  
9.1  
0.52  
9.1  
0.76  
9.1  
0.9  
27048 26013 24081 25760 24288 22402 24748 23000 20355 23184 20585 18147 21908 19171 16917  
1976 2007 2029 2152 2174 2201 2421 2421 2421 2617 2615 2622 2736 2735 2744  
8.3  
0.48  
8.3  
0.65  
8.4  
0.88  
8.9  
0.49  
9.0  
0.68  
9.0  
0.89  
10.0 10.00 10.1  
0.49 0.70 0.9  
10.8  
0.5  
10.8  
0.74  
10.8  
0.9  
11.3  
0.52  
11.3  
0.76  
11.3  
0.9  
RATING POINT  
ARI 310/380  
VHA - EXTENDED COOLING PERFORMANCE  
OUTDOOR DRY BULB TEMP. (DEGREES F AT 40% R.H.)  
85 95 105  
INDOOR WET BULB TEMP. (DEGREES F AT 80 F D.B.)  
67 62 72 67 62 72 67  
75  
110  
67  
72  
67  
62  
72  
62  
72  
62  
BTUh  
WATTS  
AMPS  
SHR  
BTUh  
WATTS  
AMPS  
SHR  
BTUh  
WATTS  
AMPS  
SHR  
BTUh  
WATTS  
AMPS  
SHR  
10819 10405 9632 10304 9715 8961 9899 9200 8142 9274 8234 7259 8763 7668 6767  
766  
3.4  
0.51  
778  
3.4  
0.69  
787  
3.5  
0.93  
835  
3.7  
0.52  
843  
3.7  
0.71  
854  
3.7  
0.95  
939  
4.1  
0.52  
939  
4.10  
0.74  
939  
4.1  
0.95  
1015 1014 1017 1061 1061 1064  
VHA09  
VHA12  
VHA18  
VHA24  
4.4  
4.4  
4.4  
4.6  
4.6  
4.6  
0.53  
0.78  
0.96  
0.55  
0.81  
0.95  
13524 13007 12041 12880 12144 11201 12374 11500 10178 11592 10293 9074 10954 9585 8458  
968  
4.4  
0.49  
983  
4.4  
0.67  
994  
4.5  
0.9  
1054 1065 1078 1186 1186 1186 1282 1281 1284 1340 1340 1344  
4.7  
0.5  
4.7  
0.7  
4.8  
0.92  
5.3  
0.51  
5.30  
0.72  
5.3  
0.92  
5.7  
0.52  
5.7  
0.76  
5.7  
0.93  
6
0.53  
6
0.79  
6
0.93  
19992 19227 17799 19040 17952 16558 18292 17000 15045 17136 15215 13413 16193 14170 12504  
1524 1549 1565 1661 1677 1698 1868 1868 1868 2019 2017 2023 2111 2110 2117  
6.8  
0.48  
6.8  
0.65  
6.9  
0.88  
7.3  
0.49  
7.3  
0.68  
7.4  
0.89  
8.2  
0.49  
8.20  
0.70  
8.2  
0.90  
8.8  
0.50  
8.8  
0.74  
8.9  
0.90  
9.2  
0.52  
9.2  
0.76  
9.3  
0.9  
27048 26013 24081 25760 24288 22402 24748 23000 20355 23184 20585 18147 21908 19171 16917  
2062 2095 2118 2247 2269 2297 2527 2527 2527 2732 2729 2737 2856 2854 2864  
8.8  
0.48  
8.8  
0.65  
8.9  
0.88  
9.4  
0.49  
9.5  
0.68  
9.5  
0.89  
10.5 10.60 10.7  
0.49 0.70 0.90  
11.4  
0.50  
11.4  
0.74  
11.4  
0.90  
11.9  
0.52  
11.9  
0.76  
12  
0.9  
RATING POINT  
ARI 310/380  
7
WARNING  
ELECTRIC SHOCK HAZARD  
Turn off electric power before service or instal-  
lation. All electrical connnections and wiring  
MUST be installed by a qualified electrician and  
conform to the National Electrical Code and all  
local codes which have jurisdiction. Failure to  
do so can result in personal injury and/or death.  
ELECTRICAL REQUIREMENTS  
Wire Size  
“Use ONLY time delayed fused disconnect or HACR type circuit breaker as indicated on the unit’s rating plate (see  
sample on this page). Proper current protection to the unit is the responsibility of the owner”.  
Unit MUST  
All units must be hard wired with properly sized breaker. See nameplate for specific chassis electrical requirements.  
See Electrical Rating Table below for wire size. Use HACR type breakers to avoid nuisance trips. All field wiring must be done  
in accordance with NEC and local codes.  
Electrical Rating Tables  
15A  
20A  
30A  
14  
12  
10  
Supply voltage  
Supply voltage to the unit should be a nominal 208/230 volts. It must be between 197 volts and 253 volts. Supply voltage to  
the unit should be checked WITH THE UNIT IN OPERATION. Voltage readings outside the specified range can be expected  
to cause operating problems. Their cause MUST be investigated and corrected.  
Sample Nameplate  
120524  
COOLING EQUIPMENT  
FOLLOWING ITEMS  
OUTDOOR GRILLE  
INDOOR GRILLE  
8
ReMOTe TheRMOsTAT AND LOw VOLTAge CONTROL  
CONNeCTIONs  
Auto On  
Cool Off Heat  
RT5 (Two speed fan)  
RT4 (One speed fan)  
Remote Thermostat  
Location  
All Friedrich Vert-I-Pak units are factory configured to be  
controlled by using a 24V single stage remote wall mounted  
thermostat. The thermostat may be auto or manual changeover  
as long as the control configuration matches that of the  
Vert-I-Pak unit.  
The thermostat should not be mounted where it may be  
affected by drafts, discharge air from registers (hot or cold),  
or heat radiated from the sun or appliances.  
The thermostat should be located about 5 Ft. above the  
floor in an area of average temperature, with good air  
circulation. Close proximity to the return air grille is the  
best choice.  
Manual Changeover Thermostat  
For Heat Pump equipped units: a single stage, heat/cool  
thermostat with a terminal for a reversing valve operation is  
required. Terminal “B” should be continuously energized in the  
heat mode and terminal “G” should be energized whenever  
there is a call for heating or cooling. (Typically, a single stage,  
heat/cool thermostat designed for use with electric heat  
systems will meet the above requirements).  
Mercury bulb type thermostats MUST be level to control  
temperature accurately to the desired set-point. Electronic  
digital type thermostats SHOULD be level for aesthetics.  
Thermostat Location  
NOTICE  
DO NOT use a two (2) stage Heat Pump Thermostat.  
Use of this type of thermostat may result in equipment  
and/or property damage  
To control the unit with a wall-mounted thermostat:  
1) Pull the disconnect switch.  
2) Unscrew and remove the control box panel.  
3) After selecting which side you want to run your thermostat  
wire through, run the wires through the side hole in the box  
to reach the connection terminal for the wiring.  
4) Make the wire connections, appropriately matching the  
wires as shown in the wiring diagram.  
5) Once each wire is matched and connected, the unit is now  
controlled by the thermostat.  
NOTE: An improperly operating, or poorly located room  
thermostat can be the source of perceived equipment  
problems. A careful check of the thermostat and wiring  
must be made then to insure that it is not the source of  
problems.  
6) Reattach the control box cover.  
9
ReMOTe TheRMOsTAT AND LOw VOLTAge CONTROL  
CONNeCTIONs (Continued)  
Thermostat Connections  
For desk control operation, connect one side of the switch to  
the D1 terminal and the other to the D2 terminal. Whenever  
the switch closes, the unit operation will stop.  
C
W
Y
=
=
=
=
Common Ground  
Call for Heating  
Call for Cooling  
Maximum Wire Length for Desk Control Switch  
R
24V Power from Unit  
Wire Size  
#24  
Maximum Length  
400 ft.  
GL = Call for Fan (Low Speed)  
GH = Call for Fan (High Speed)  
#22  
600 ft.  
B
=
Reversing Valve Energized in heating mode  
Note: The desk  
control system and  
switches must be  
field supplied.  
#20  
900 ft.  
*If only one G terminal is present on thermostat, connect  
to GL for low fan or to GH for high fan operation.  
#18  
1500 ft.  
#16  
2000 ft.  
NOTE: It is the installer’s responsibility to ensure that all  
control wiring connections are made in accordance with  
the Freidrich installation instructions. Questions concern-  
ing proper connections to the unit should be directed to  
the factory: 210-357-4400.  
Auxiliary Fan Control  
The Smart Center also has the ability to control a 24VAC  
relay to activate an auxiliary, or transfer, fan. The outputs  
are listed as F1 and F2 on the control board.  
Desk Control Terminals  
To connect the relay, simply wire one side of the relay to  
F1 and the other side to F2. Anytime that the fan runs, the  
terminals will send a 24VAC signal to the relay. The relay  
must be 24 VAC, 50mA or less.  
The Friedrich VERT-I-PAK has built-in provisions for  
connection to an external switch to control power to the unit.  
The switch can be a central desk control system or even a  
normally open door switch.  
Note: The relay and auxiliary fans must be field supplied.  
10  
eLeCTRONIC CONTROL BOARD FeATURes  
The new Friedrich Vert-I-Pak has state of the art features to improve guest comfort and conserve energy. Through  
the use of specifically designed control software, Friedrich has accomplished what other Manufacturer’s have only  
attempted – a quiet, dependable, affordable and easy to use Vert-I-Pak.  
Below is a list of standard features on every Friedrich VPAK and their benefit to the owner.  
The fan start and stop delays prevent abrupt changes in room acoustics due to the compressor energizing  
Quiet Start/Stop  
or stopping immediately. Upon call for cooling or heating the unit fan will run for five seconds prior to en-  
ergizing the compressor. Also, the fan off delay allows for “free cooling” by utilizing the already cool indoor  
coil to its maximum capacity by running for 30 seconds after the compressor.  
Fan Delay  
Remote Thermostat  
Operation  
VPAK units are thermostat controlled.  
The new Friedrich digital VPAK features a self diagnostic program that can alert maintenance to compo-  
nent failures or operating problems. The internal diagnostic program saves properties valuable time when  
diagnosing running problems.  
Internal Diagnostic  
Program  
The self diagnosis program will also store error codes in memory if certain conditions occur and correct  
themselves such as extreme high or low operating conditions or activation of the room freeze protection  
feature. Storing error codes can help properties determine if the unit faced obscure conditions or if an error  
occurred and corrected itself.  
Service Error Code  
Storage  
When the VPAK senses that the indoor room temperature has fallen to 40°F the unit will cycle on high fan  
and the electric strip heat to raise the room temperature to 46°F then cycle off again. This feature works  
regardless of the mode selected and can be turned off. The control will also store the Room Freeze cycle  
in the service code memory for retrieval at a later date. This feature ensures that unoccupied rooms do not  
reach freezing levels where damage can occur to plumbing and fixtures.  
Room Freeze  
Protection  
Multiple compressors starting at once can often cause electrical overloads and premature unit failure.  
The random restart delay eliminates multiple units from starting at once following a power outage or initial  
power up. The compressor delay will range from 180 to 240 seconds.  
Random  
Compressor Restart  
The new Friedrich VPAK uses a digital thermostat to accurately monitor the outdoor coil conditions to allow  
the heat pump to run whenever conditions are correct. Running the VPAK in heat pump mode save energy  
and reduces operating costs. The digital thermostat allows maximization of heat pump run time.  
Digital Defrost  
Thermostat  
Heat pump models will automatically run the electric heater during compressor lock-out to quickly provide  
heat when initially energized, then return to heat pump mode. This ensures that the room is heated quickly  
without the usual delay associated with heat pump units.  
Instant Heat  
Heat Pump Mode  
In the event of a compressor failure in heat pump mode the compressor may be locked out to provide heat  
through the resistance heater. This feature ensures that even in the unlikely event of a compressor failure  
the room temperature can be maintained until the compressor can be serviced.  
Emergency Heat  
Override  
All electronic VPAK units have low voltage terminals ready to connect a desk control energy management  
system. Controlling the unit from a remote location like the front desk can reduce energy usage and  
requires no additional accessories at the VPAK.  
Desk Control Ready  
The frost sensor protects the compressor from damage in the event that airfl ow is reduced or low outdoor  
temperatures cause the indoor coil to freeze. When the indoor coil reaches 30°F the compressor is  
diabled and the fan continues to operate based on demand. Once the coil temperature returns to 45°F the  
compressor returns to operation.  
Indoor Coil Frost  
Sensor  
Ultra-Quiet Air  
System  
The VPAK series units feature a indoor fan system design that reduces sound levels without  
lowering airflow and preventing proper air circulation.  
The VPAK benefits quality components and extensive development to ensure a quiet, efficient and  
dependable unit.  
High Efficiency  
High efficiency rotary compressors are used on all Friedrich VPAKs to maximize durability and efficiency.  
Rotary Compressor  
Auxiliary Fan Ready  
The VPAK features a 24V AC terminal for connection to an auxiliary fan that may be used to transfer air to  
adjoining rooms. Auxiliary fans can provide conditioning to multiple rooms.  
11  
Electronic Control Configuration  
Electronic Control Error Code  
Diagnostics and Test Mode  
The adjustable control dip switches are located at the lower  
left hand portion of the digital Smart Center. The inputs are  
only visible and accessible with the front cover removed from  
the Unit.  
Error Code Diagnostics  
The VPAK electronic control continuously monitors the Vert-I-Pak  
unit operation and will store error codes if certain conditions  
are witnessed. In some cases the unit may take action and shut  
the unit off until conditions are corrected.  
Factory Dip Switch Configuration  
1 2 3 4 5 6 7 8  
O
To access the error code menu press the ‘HEAT’ and ‘HIGH  
FAN’ buttons simultaneously for three seconds. If error codes  
are present they will be displayed. If multiple codes exist you  
can toggle between error codes using the temp up ▲ button. To  
clear all codes press the temp down ▼ button for three seconds  
while in the error code mode. To exit without losing codes  
press the ‘Low Fan’ button.  
N
Dip Switch Setting  
Switches 1-4 ON  
Switch 5-7 OFF  
Switch 8 ON  
Button Location for Vert-I-Pak Models  
With the remote thermostat escutcheon installed, the button  
locations to access the diagnostics mode can be located as  
shown below.  
Room Freeze Protection – Switch 6  
Units are shipped from the factory with the room freeze protec-  
tion disabled. Room Freeze Protection can be switched on at  
the owner’s preference by moving Dip Switch 6 to ‘ON’. This  
feature will monitor the indoor room conditions and in the event  
that the room falls below 40°F the unit will cycle on high fan with  
the electric heater. This occurs regardless of mode.  
Cool  
High fan  
Heat  
Emergency Heat Override – Switch 7  
Power  
Temp  
Units are shipped from the factory with the room emergency  
heat override disabled. In the unlikely event of a compressor  
failure a heat pump unit may be switched to operate in only the  
electric heat mode until repairs can be made, by moving Dip  
Switch 7 to ‘ON’.  
Temp  
Fan only  
Low fan  
Discharge Air Sensor Override – Switch 8  
* Heat and high fan - access error codes  
This switch MUST remain in the “ON” position for Vert-I-Pak  
models, since they do not use a discharge air sensor. If the  
switch is positioned in the “OFF” position on these models it  
will result in the erroneous display Error Code 14 indicating that  
the Discharge air temperature sensor is open or shorted.  
* Temp up ▲ and temp down ▼ - toggle between error codes  
* Low fan - exit error code mode without losing stored error  
codes.  
* Temp down ▼ - clears all error codes  
Note: In order for the control to recognize “Dip” switch  
setting changes, the unit must be disconnected  
from power supply when making any configuration  
changes.  
NOTE: Hold buttons down for three seconds.  
12  
electronic Control error Code Diagnostics  
Error  
Code  
Code Translation  
Action Taken By Unit  
Possible Cause  
EF  
Error Free  
None  
Unit Operating Normally  
Shut unit down. Flash error code.  
voltage rises to adequate level normal unit • Defective breaker  
operation is restored.  
When • Inadequate power supply  
Extreme low voltage condition exists (<198V  
for 230V units and <239V for 265V units).  
02  
• Blown fuse  
Return air thermistor sensor open or  
short circuit  
Indoor coil thermistor sensor open or  
short circuit  
Leave unit running. Alternately flash error  
code and set point.  
Leave unit running. Alternately flash  
error code and set point.  
03  
04  
• Defective sensor  
Leave unit running. Switch to Electric Heat  
Mode (Heat Pump only). Alternately flash  
error code and set point.  
Outdoor coil thermistor sensor open  
or short circuit  
05  
06  
• Defective sensor  
Shut unit down for 5 minutes, Alternately  
flash error code and set point, then try again  
2 times, if unit fails the 3rd time then shut  
unit down and alternately flash error code  
and set point.  
• Dirty coil  
• Fan motor failure  
• Restricted air flow  
• Non-condensables in refrigeration system  
Outdoor coil Temperature > 175° F for  
2 consecutive minutes. (Heat Pump  
models only)  
Shut down Compressor, and continue fan  
• Dirty filters  
operation. Alternately flash error code and • Dirty coil  
Indoor coil temperature <30° F for 2  
consecutive minutes.  
set point until the indoor coil thermistor  
reaches 45° F. Then, (after lockout time of • Restricted air flow  
• Fan motor failure  
07  
180 to 240 seconds expires), re-energize  
the compressor .  
• Improper refrigerant charge  
• Restriction in refrigerant circuit  
Leave unit running. Store error code in  
memory.  
Unit cycles (Heat or Cool demand) >  
9 times per hour  
• Unit oversized  
• Low load conditions  
08  
09  
Leave unit running. Store Error Code in  
memory.  
Unit cycles (Heat or Cool demand) <  
3 times per hour  
• Unit undersized  
• High load conditions  
Leave unit running. Alternately flash error  
code and set point.  
10  
11  
Room Freeze Protection triggered  
No Signal to “GL or “GH” terminal  
• Room temperature fell below 40°F  
• Defective remote thermostat  
• Defective thermostat wiring  
• Dirty coil  
• Fan motor failure  
• Restricted air flow  
Shut unit down. Flash error code.  
Shut unit down. Flash error code.  
High Pressure switch open (24K BTU Only)  
Jumper wire loose/missing (9-18K BTU)  
13  
14  
• Non-condensables in refrigeration system  
Discharge air temperature sensor open or  
shorted  
Leave unit running. Alternately flash error  
code and set point.  
• Dip switch # 8 set to "OFF" position  
Diagnostics  
The Electronic control continuously monitors the VPAK unit operation and will store service codes if certain  
conditions are witnessed. In some cases the unit may take action and shut the unit off until conditions are corrected.  
To access the error code menu press the ‘Heat’ and ‘High Fan’ buttons simultaneously for three seconds. If  
error codes are present they will be displayed. If multiple codes exist you can toggle between messages using the  
temp up  
button. To clear all codes press the temp down  
button for three seconds while in the error code mode. To  
exit without changing codes press the ‘Low Fan’ button.  
Test Mode  
For service and diagnostic use only, the built-in timers and delays on the VPAK may be bypassed by pressing the ‘Cool’ and  
‘Low Fan’ buttons simultaneously for three seconds while in any mode to enter the test mode. CE will be displayed when en-  
tering test mode, and oE will be displayed when exiting. The test mode will automatically be exited 30 minutes after entering it  
or by pressing the ‘Cool’ and ‘Low Fan’ buttons simultaneously for three seconds.  
Note: To access the Test Mode while under remote wall thermostat operation, remove thermostat’s wires at the  
terminal block on the electronic control board then connect a jumper wire between GL and GH.  
13  
VPAk eLeCTRONIC CONTROL FeATURes  
Thermostat Compatibility:  
Note: The Compressor Time Delay feature is  
The VPAK Electronic Control is compatible with  
Friedrich RT4 and RT5 Thermostats.  
The VPAK Electronic control is also compatible  
with most standard Single Stage Heat/Cool  
Thermostats.  
disabled during “Test Mode” operation.  
Fan delay:  
The Electronic Control is equipped with a  
feature that will start the fan 5 seconds EARLY  
(i.e. before compressor or heater) when unit  
cycles “ON.” When the unit cycles “OFF” the  
fan will DELAY for 30 seconds in Cooling and  
15 seconds in Heating.  
NOTE: Field supplied Thermostats MUST  
energize the fan circuit on a call for Heating  
or Cooling, and (when used with a Heat  
Pump Unit) MUST energize the “B” terminal  
in Heating in order for the unit to function  
correctly.  
Note: the fan delay is disabled during Test  
Mode operation.  
Compressor Time Delay:  
The Electronic control is equipped with a  
random (180 to 240 seconds) Compressor  
time delay that is initiated every time the  
compressor cycles “Off.” The “delay on break”  
timer is initiated by the following actions:  
(1) Satisfying the temperature set point  
(2) Changing mode to fan only  
Emergency Heat:  
The Electronic Control is equipped with a  
feature that allows servicer/end user to switch  
to electric heat operation when the compressor  
fails during the heating season, (See DIP  
switch position 7) until the compressor can be  
replaced.  
(3) Turning the unit off  
(4) Restoring power after a failure  
14  
External Static Pressure  
External Static Pressure can best be defined as the pressure  
difference (drop) between the Positive Pressure (discharge)  
and the Negative Pressure (intake) sides of the blower.  
External Static Pressure is developed by the blower as a  
result of resistance to airflow (Friction) in the air distribution  
system EXTERNAL to the VERT-I-PAK cabinet.  
1. Set up to measure external static pressure at the  
supply and return air.  
2. Ensure the coil and filter are clean, and that all the  
registers are open.  
3. Determine the external static pressure with the  
blower operating.  
Resistance applied externally to the VERT-I-PAK (i.e. duct  
work, filters, etc.) on either the supply or return side of the  
system causes an INCREASE in External Static Pres-  
sure accompanied by a REDUCTION in airflow.  
4. Refer to the Air Flow Data for your VERT-I-PAK  
system to find the actual airflow for factory-selected  
fan speeds.  
External Static Pressure is affected by two (2) factors.  
5. If the actual airflow is either too high or too low, the  
blower speed will need to be changed to appropriate  
setting or the ductwork will need to be reassessed  
and corrections made as required.  
1. Resistance to Airflow as already explained.  
2. Blower Speed. Changing to a higher or lower blower  
speed will raise or lower the External Static Pressure  
accordingly.  
6. Select a speed, which most closely provides the  
required airflow for the system.  
Theseaffectsmustbeunderstoodandtakenintoconsideration  
whencheckingExternal StaticPressure/Airflow to insure that  
the system is operating within design conditions.  
7. Recheck the external static pressure with the  
new speed. External static pressure (and actual  
airflow) will have changed to a higher or lower value  
depending upon speed selected. Recheck the actual  
airflow (at this "new" static pressure) to confirm  
speed selection.  
Operating a system with insufficient or excessive airflow  
can cause a variety of different operating problems.  
Among these are reduced capacity, freezing evaporator  
coils, premature compressor and/or heating component  
failures. etc.  
8. Repeat steps 8 and 9 (if necessary) until proper  
airflow has been obtained.  
System airflow should always be verified upon completion  
of a new installation, or before a change-out, compressor  
replacement, or in the case of heat strip failure to insure  
that the failure was not caused by improper airflow.  
EXAMPLE: Airflow requirements are calculated as follows:  
(Having a wet coil creates additional resistance to airflow.  
This addit ional resistance must be taken into consideration  
to obtain accurate airflow information.  
Determining the Indoor CFM: Chart A – CFM  
Model  
VEA09/VHA09 VEA12/VHA12 VEA18/VHA18  
ESP (") Low  
High  
385  
340  
280  
190  
Low  
420  
350 *  
290  
High  
470  
420 **  
350  
Low  
430  
400  
340  
290  
High  
480  
450  
400  
330  
.00"  
.10"  
.20"  
.30”  
340  
300  
230  
140  
250  
300  
Highlighted values indicate rated performance point.  
Rated performance for  
VEA12  
*
Rated Performance for  
** VHA12  
Model  
VEA24/VHA24  
ESP (")  
.00"  
.10"  
.20"  
.30"  
Low  
690  
610  
560  
510  
450  
High  
740  
700  
640  
580  
520  
Checking External Static Pressure  
The airflow through the unit can be determined by  
measuring the external static pressure of the system, and  
consulting the blower performance data for the specific  
VERT-I-PAK.  
.40"  
Highlighted values indicate rated performance point.  
15  
Correct CFM (if needed):  
Chart B – Correction Multipliers  
Ductwork Preparation  
If flex duct is used, be sure all the slack is pulled out of the  
flex duct. Flex duct ESP can increase considerably when  
not fully extended. DO NOT EXCEED a total of .30 ESP, as  
this is the MAXIMUM design limit for the VERT-I-PAK  
A-Series unit.  
IMPORTANT: FLEX DUCT CAN COLLAPSE AND  
CAUSE AIRFLOW RESTRICTIONS. DO NOT  
USE FLEX DUCT FOR: 90 DEGREE BENDS, OR  
UNSUPPORTED RUNS OF 5 FT. OR MORE.  
Explanation of charts  
Chart A is the nominal dry coil VERT-I-PAK CFMs. Chart  
B is the correction factors beyond nominal conditions.  
Fresh Air Door  
The Fresh Air Door is an “intake” system. The fresh air door  
opened via a slide on the front of the chassis located just  
above the indoor coil. Move the slide left to open and right  
to close the fresh air door. The system is capable of up to 60  
CFM of fresh air @ ~.3” H20 internal static pressure.  
1 ½ TON SYSTEM ( 18,000 Btu)  
Operating on high speed @ 230 volts with dry coil  
measured external static pressure .10  
Air Flow = 450 CFM  
Checking Approximate Airflow  
If an inclined manometer or Magnehelic gauge is not  
available to check the External Static Pressure, or the  
blower performance data is unavailable for your unit,  
approximate air flow call be calculated by measuring the  
temperature rise, then using tile following criteria.  
In the same SYSTEM used in the previous example but  
having a WET coil you must use a correction factor of  
.95 (i.e. 450 x .95=428 CFM) to allow for the resistance  
(internal) of the condensate on the coil.  
KILOWATTS x 3413  
= CFM  
It is important to use the proper procedure to check external  
Static Pressure and determine actual airflow. Since in  
the case of the VERT-I-PAK, the condensate will cause  
a reduction in measured External Static Pressure for the  
given airflow.  
Temp Rise x 1.08  
Electric Heat Strips  
The approximate CFM actually being delivered can be  
calculated by using the following formula:  
It is also important to remember that when dealing with  
VERT-l-PAK units that the measured External Static  
Pressure increases as the resistance is added externally  
to the cabinet. Example: duct work, filters, grilles.  
DO NOT simply use the Kilowatt Rating of the heater (i.e.  
2.5, 3.4, 5.0) as this will result in a less-than-correct airflow  
calculation. Kilowatts may be calculated by multiplying  
the measured voltage to the unit (heater) times the  
measured current draw of all heaters (ONLY) in operation  
to obtain watts. Kilowatts are than obtained by dividing  
by 1000.  
Indoor Airflow Data  
The Vert-I-Pak A series units must be installed with a free  
return air configuration. The table below lists the indoor  
airflow at corresponding static pressures. All units are rarted  
at low speed.  
EXAMPLE: Measured voltage to unit (heaters) is 230 volts.  
Measured Current Draw of strip heaters is 11.0 amps.  
The Vert-I-Pak units are designed for either single speed or  
two fan speed operation. For single speed operation refer to  
the airflow table below and select the most appropriate CFM  
based on the ESP level. Connect the fan output from the  
thermostat to the unit on either the GL terminal for low speed  
or to the GH terminal for high speed operation.  
230 x 11.0 = 2530  
2530/1000 = 2.53 Kilowatts  
2.53 x 3413 = 8635  
°
Supply Air  
Return Air  
95 F  
°
75 F  
°
Temperature Rise  
20  
For thermostats with two-speed fan outputs connect the low  
speed output to the unit GL terminal and the high speed  
output to the GH terminal.  
20 x 1.08 = 21.6  
8635  
= 400 CFM  
21.6  
16  
COMPONeNTs TesTINg  
BLOWER / FAN MOTOR  
Many motor capacitors are internally fused. Shorting the  
terminals will blow the fuse, ruining the capacitor. A 20,000  
ohm 2 watt resistor can be used to discharge capacitors  
safely. Remove wires from capacitor and place resistor  
across terminals. When checking a dual capacitor with  
a capacitor analyzer or ohmmeter, both sides must be  
tested.  
Asingle phase permanentsplit capacitor motor is usedto drive  
the evaporator blower and condenser fan. A self-resetting  
overload is located inside the motor to protect against high  
temperature and high amperage conditions.  
WARNING  
ELECTRIC SHOCK HAZARD  
Capacitor Check with Capacitor Analyzer  
Disconnect power to the unit before  
servicing. Failure to follow this warning  
could result in serious injury or death.  
The capacitor analyzer will show whether the capacitor  
is “open” or “shorted.” It will tell whether the capacitor  
is within its micro farads rating and it will show whether  
the capacitor is operating at the proper power-factor  
percentage. The instrument will automatically discharge  
the capacitor when the test switch is released.  
BLOWER / FAN MOTOR TEST  
1. Visually inspect the motor’s wiring, housing etc., and  
determine that the capacitor is serviceable.  
2. Make sure the motor has cooled down.  
3. Disconnect the fan motor wires from the control board.  
4. Test for continuity between the windings also, test to  
ground.  
Capacitor Connections  
The starting winding of a motor can be damaged by a  
shorted and grounded running capacitor. This damage  
usually can be avoided by proper connection of the running  
capacitor terminals.  
5. If any winding is open or grounded replace the motor.  
From the supply line on a typical 230 volt circuit, a 115 volt  
potential exists from the “R” terminal to ground through a  
possibleshortinthecapacitor. However, fromthe“S”orstart  
terminal, a much higher potential, possibly as high as 400  
volts, exists because of the counter EMF generated in the  
start winding. Therefore, the possibility of capacitor failure  
is much greater when the identified terminal is connected  
to the “S” or start terminal. The identified terminal should  
always be connected to the supply line, or “R” terminal,  
never to the “S” terminal.  
When connected properly, a shorted or grounded running  
capacitor will result in a direct short to ground from the “R”  
terminal and will blow the line fuse. The motor protector  
will protect the main winding from excessive temperature.  
CAPACITORs  
WARNING  
ELECTRIC SHOCK HAZARD  
Turn off electric power before servicing.  
Discharge capacitor with a 20,000 Ohm 2 Watt  
resistor before handling.  
Failure to do so may result in personal injury,  
or death.  
17  
COMPONeNTs TesTINg (Continued)  
HEATER ELEMENTS AND LIMIT SWITCHES’  
SPECIFICATIONS  
All heat pumps and electric heat models are equipped  
with a heating element and a limit switch (bimetal ther-  
mostat). The limit is in series with the element and will  
interrupt the power at a designed temperature.  
DRAIN PAN VALVE  
During the cooling mode of operation, condensate which  
collects in the drain pan is picked up by the condenser fan  
blade and sprayed onto the condenser coil. This assists  
in cooling the refrigerant plus evaporating the water.  
During the heating mode of operation, it is necessary that  
water be removed to prevent it from freezing during cold  
outside temperatures. This could cause the condenser  
fan blade to freeze in the accumulated water and prevent  
it from turning.  
Should the blower motor fail, filter become clogged or air-  
flow be restricted etc., the high limit switch will open and  
interrupt the power to the heater before reaching an un-  
safe temperature condition.  
To provide a means of draining this water, a bellows type  
drain valve is installed over a drain opening in the base  
pan.  
TESTING THE HEATING ELEMENTS AND  
LIMIT SWITCHES  
WARNING  
This valve is temperature sensitive and will open when  
the outside temperature reaches 40°F. The valve will  
close gradually as the temperature rises above 40°F to  
fully close at 60°F.  
ELECTRIC SHOCK HAZARD  
Disconnect power to the unit before  
servicing. Failure to follow this warning  
could result in serious injury or death.  
Bellows Assembly  
Drain Pan Valve  
Testing of the heating elements can be made with an  
ohmmeter or continuity tester across the terminals after  
the power wires have been removed. Test the limit switch  
for continuity across its input and output terminals.Test  
below the limit switch’s reset temperature.  
18  
ReFRIgeRATION seQUeNCe OF OPeRATION  
A good understanding of the basic operation of the  
refrigeration system is essential for the service technician.  
Without this understanding, accurate troubleshooting of  
refrigeration system problems will be more difficult and time  
consuming, if not (in some cases) entirely impossible. The  
refrigeration system uses four basic principles (laws) in its  
operation they are as follows:  
The refrigerant leaves the condenser Coil through the liquid  
line as a warm high pressure liquid. It next will pass through  
the refrigerant drier (if so equipped). It is the function of the  
driertotrapanymoisturepresentinthesystem,contaminants,  
and large particulate matter.  
The liquid refrigerant next enters the metering device. The  
metering device is a capillary tube. The purpose of the  
metering device is to “meter” (i.e. control or measure) the  
quantity of refrigerant entering the evaporator coil.  
1. “Heat always flows from a warmer body to a cooler  
body.”  
2. “Heat must be added to or removed from a substance  
before a change in state can occur”  
In the case of the capillary tube this is accomplished (by  
design) through size (and length) of device, and the pressure  
difference present across the device.  
3. “Flow is always from a higher pressure area to a lower  
pressure area.”  
Since the evaporator coil is under a lower pressure (due to  
the suction created by the compressor) than the liquid line,  
the liquid refrigerant leaves the metering device entering the  
evaporator coil. As it enters the evaporator coil, the larger  
area and lower pressure allows the refrigerant to expand  
and lower its temperature (heat intensity). This expansion is  
often referred to as “boiling”. Since the unit’s blower is moving  
indoor air across the finned surface of the evaporator coil,  
the expanding refrigerant absorbs some of that heat. This  
results in a lowering of the indoor air temperature, hence the  
“cooling” effect.  
4. “The temperature at which a liquid or gas changes state  
is dependent upon the pressure.”  
The refrigeration cycle begins at the compressor. Starting  
the compressor creates a low pressure in the suction line  
which draws refrigerant gas (vapor) into the compressor.  
The compressor then “compresses” this refrigerant, raising  
its pressure and its (heat intensity) temperature.  
The refrigerant leaves the compressor through the discharge  
Line as a hot High pressure gas (vapor). The refrigerant  
enters the condenser coil where it gives up some of its  
heat. The condenser fan moving air across the coil’s finned  
surface facilitates the transfer of heat from the refrigerant to  
the relatively cooler outdoor air.  
The expansion and absorbing of heat cause the liquid  
refrigerant to evaporate (i.e. change to a gas). Once the  
refrigerant has been evaporated (changed to a gas), it is  
heated even further by the air that continues to flow across  
the evaporator coil.  
When a sufficient quantity of heat has been removed from  
the refrigerant gas (vapor), the refrigerant will “condense”  
(i.e. change to a liquid). Once the refrigerant has been  
condensed (changed) to a liquid it is cooled even further by  
the air that continues to flow across the condenser coil.  
The particular system design determines at exactly what  
point (in the evaporator) the change of state (i.e. liquid to a  
gas) takes place. In all cases, however, the refrigerant must  
be totally evaporated (changed) to a gas before leaving the  
evaporator coil.  
The VPAK design determines at exactly what point (in  
the condenser) the change of state (i.e. gas to a liquid)  
takes place. In all cases, however, the refrigerant must be  
totally condensed (changed) to a Liquid before leaving the  
condenser coil.  
The low pressure (suction) created by the compressor  
causes the refrigerant to leave the evaporator through the  
suction line as a cool low pressure vapor. The refrigerant then  
returns to the compressor, where the cycle is repeated.  
Refrigeration Assembly  
1. Compressor  
2. Evaporator Coil Assembly  
3. Condenser Coil Assembly  
4. Capillary Tube  
5. Compressor Overload  
19  
seRVICe  
Servicing / Chassis Quick Changeouts  
WARNING  
ELECTRIC SHOCK HAZARD  
Turn off electric power before service or  
installation.  
.
Extreme care must be used, if it becomes  
necessary to work on equipment with power  
applied.  
To Remove the Chassis from the Closet:  
A. Disconnect the power coming into the unit from the main  
breaker panel or the closet mounted disconnect.  
B. Switch the wall Thermostat off.  
Failure to do so could result in serious injury or  
death.  
C. Pull the Power Disconnect located in the front of the chassis.  
D. Disconnect the electrical connection.  
E. Disconnect the duct work.  
F. Disconnect condensate drain on 9-18,000 BTU models.  
G. Slide the chassis out of the wall plenum.  
H. Lift the chassis out of the utility closet.  
CAUTION  
CUT/SEVER HAZARD  
Be careful with the sharp edges and corners.  
Wear protective clothing and gloves, etc.  
Failure to do so could result in minor to  
moderate injury.  
Warranty  
20  
seALeD ReFRIgeRATION sYsTeM RePAIRs  
IMPORTANT  
ANY SEALED SYSTEM REPAIRS TO COOL-ONLY MODELS REQUIRE THE INSTALLATION OF A LIQUID LINE DRIER.  
ALSO, ANY SEALED SYSTEM REPAIRS TO HEAT PUMP MODELS REQUIRE THE INSTALLATION OF A SUCTION LINE DRIER.  
EQUIPMENT REQUIRED:  
9. High Pressure Gauge - (0 - 750 lbs.)  
1. Voltmeter  
10. Low Pressure Gauge - (30 - 200 lbs.)  
2. Ammeter  
11. Vacuum Gauge - (0 - 1000 microns)  
3. Ohmmeter  
12. Facilities for flowing nitrogen through refrigeration tubing  
4. E.P.A. Approved Refrigerant Recovery System  
during all brazing processes.  
5. Vacuum Pump (capable of 200 microns or less  
vacuum.)  
EQUIPMENT MUST BE CAPABLE OF:  
6. Acetylene Welder  
1. Recovering refrigerant to EPA required levels.  
7. Electronic Halogen Leak Detector capable of detect-  
ing HFC (Hydrofluorocarbon) refrigerants.  
2. Evacuation from both the high side and low side of the  
system simultaneously.  
8. Accurate refrigerant charge measuring device such  
as:  
3. Introducing refrigerant charge into high side of the  
system.  
a. Balance Scales - 1/2 oz. accuracy  
b. Charging Board - 1/2 oz. accuracy  
4. Accurately weighing the refrigerant charge actually  
introduced into the system.  
Too much refrigerant (overcharge) in the system is just as bad  
(if not worse) than not enough refrigerant (undercharge). They  
both can be the source of certain compressor failures if they  
remain uncorrected for any period of time. Quite often, other  
problems (such as low air flow across evaporator, etc.) are  
misdiagnosed as refrigerant charge problems. The refrigerant  
circuit diagnosis chart will assist you in properly diagnosing  
these systems.  
WARNING  
RISK OF ELECTRIC SHOCK  
Unplug and/or disconnect all electrical power  
to the unit before performing inspections,  
maintenances or service.  
Failure to do so could result in electric shock,  
serious injury or death.  
An overcharged unit will at times return liquid refrigerant  
(slugging) back to the suction side of the compressor eventually  
causing a mechanical failure within the compressor. This  
mechanical failure can manifest itself as valve failure, bearing  
failure, and/or other mechanical failure. The specific type of  
failure will be influenced by the amount of liquid being returned,  
and the length of time the slugging continues.  
WARNING  
HIGH PRESSURE HAZARD  
SealedRefrigerationSystemcontainsrefrigerant  
and oil under high pressure.  
Proper safety procedures must be followed,  
and proper protective clothing must be worn  
when working with refrigerants.  
Not enough refrigerant (undercharge) on the other hand, will  
cause the temperature of the suction gas to increase to the point  
where it does not provide sufficient cooling for the compressor  
motor. When this occurs, the motor winding temperature will  
increase causing the motor to overheat and possibly cycle open  
the compressor overload protector. Continued overheating of  
the motor windings and/or cycling of the overload will eventually  
lead to compressor motor or overload failure.  
Failure to follow these procedures could  
result in serious injury or death.  
Refrigerant Charging  
Proper refrigerant charge is essential to proper unit opera-  
tion. Operating a unit with an improper refrigerant charge will  
result in reduced performance (capacity) and/or efficiency.  
Accordingly, the use of proper charging methods during ser-  
vicing will insure that the unit is functioning as designed and  
that its compressor will not be damaged.  
21  
Method Of Charging / Repairs  
CAUTION  
The acceptable method for charging the RAC system is the  
Weighed in Charge Method. The weighed in charge method is  
applicable to all units. It is the preferred method to use, as it is  
the most accurate.  
FREEZE HAZARD  
Proper safety procedures must be followed,  
and proper protective clothing must be worn  
when working with liquid refrigerant.  
The weighed in method should always be used whenever  
a charge is removed from a unit such as for a leak repair,  
compressor replacement, or when there is no refrigerant  
charge left in the unit. To charge by this method, requires the  
following steps:  
Failure to follow these procedures could  
result in minor to moderate injury.  
4. Make necessary repairs to system.  
1. Install a piercing valve to remove refrigerant from the  
sealedsystem. (Piercing valve must be removed from the  
system before recharging.)  
5. Evacuate system to 200 microns or less.  
6. Weigh in refrigerant with the property quantity of R-410A  
2. Recover Refrigerant in accordance with EPA regulations.  
refrigerant.  
7. Start unit, and verify performance.  
WARNING  
BURN HAZARD  
WARNING  
Proper safety procedures must be followed,  
and proper protective clothing must be worn  
when working with a torch.  
BURN HAZARD  
Proper safety procedures must be followed,  
and proper protective clothing must be worn  
when working with a torch.  
Failure to follow these procedures could  
result in moderate or serious injury.  
Failure to follow these procedures could  
result in moderate or serious injury.  
3. Install a process tube to sealed system.  
8. Crimp the process tube and solder the end shut.  
Undercharged Refrigerant systems  
An undercharged system will result in poor performance  
(low pressures, etc.) in both the heating and cooling  
cycle.  
WARNING  
ELECTRIC SHOCK HAZARD  
Turn off electric power before service or  
installation.  
Whenever you service a unit with an undercharge of  
refrigerant, always suspect a leak. The leak must be  
repaired before charging the unit.  
Extreme care must be used, if it becomes  
necessary to work on equipment with power  
applied.  
To check for an undercharged system, turn the unit on,  
allow the compressor to run long enough to establish  
working pressures in the system (15 to 20 minutes).  
Failure to do so could result in serious injury or  
death.  
During the cooling cycle you can listen carefully at the exit  
of the metering device into the evaporator; an intermittent  
hissing and gurgling sound indicates a low refrigerant  
charge. Intermittent frosting and thawing of the evaporator  
is another indication of a low charge, however, frosting  
and thawing can also be caused by insufficient air over  
the evaporator.  
WARNING  
HIGH PRESSURE HAZARD  
SealedRefrigerationSystemcontainsrefrigerant  
and oil under high pressure.  
Proper safety procedures must be followed,  
and proper protective clothing must be worn  
when working with refrigerants.  
Checks for an undercharged system can be made at  
the compressor. If the compressor seems quieter than  
normal, it is an indication of a low refrigerant charge.  
Failure to follow these procedures could  
result in serious injury or death.  
A check of the amperage drawn by the compressor  
motor should show a lower reading. (Check the Unit  
Specification.)  
22  
After the unit has run 10 to 15 minutes, check the gauge Improper air flow over the evaporator coil may indicate  
pressures.Gaugesconnectedtosystemwithanundercharge some of the same symptoms as an over charged system.  
will have low head pressures and substantially low suction An overcharge can cause the compressor to fail, since it  
pressures.  
would be “slugged” with liquid refrigerant.  
The charge for any system is critical. When the compressor  
is noisy, suspect an overcharge, when you are sure that the  
air quantity over the evaporator coil is correct. Icing of the  
evaporator will not be encountered because the refrigerant  
will boil later if at all. Gauges connected to system will usually  
have higher head pressure (depending upon amount of over  
charge). Suction pressure should be slightly higher.  
Overcharged Refrigerant systems  
Compressor amps will be near normal or higher.  
Noncondensables can also cause these symptoms. To  
confirm, remove some of the charge, if conditions improve,  
system may be overcharged. If conditions don’t improve,  
Noncondensables are indicated.  
Wheneveranoverchargedsystemisindicated,alwaysmake  
sure that the problem is not caused by air flow problems.  
Restricted Refrigerant system  
Troubleshooting a restricted refrigerant system can be  
difficult. The following procedures are the more common  
problems and solutions to these problems. There are two  
types of refrigerant restrictions: Partial restrictions and  
complete restrictions.  
With a complete restriction the current drawn may be  
considerably less than normal, as the compressor is  
running in a deep vacuum (no load.) Much of the area of  
the condenser will be relatively cool since most or all of the  
liquid refrigerant will be stored there.  
A partial restriction allows some of the refrigerant to  
circulate through the system.  
The following conditions are based primarily on a system  
in the cooling mode.  
With a complete restriction there is no circulation of  
refrigerant in the system.  
Restricted refrigerant systems display the same symptoms  
as a “low-charge condition.”  
When the unit is shut off, the gauges may equalize very  
slowly.  
Gauges connected to a completely restricted system will  
run in a deep vacuum. When the unit is shut off, the gauges  
will not equalize at all.  
A quick check for either condition begins at the evaporator.  
With a partial restriction, there may be gurgling sounds  
at the metering device entrance to the evaporator. The  
evaporator in a partial restriction could be partially frosted  
or have an ice ball close to the entrance of the metering  
device. Frost may continue on the suction line back to the  
compressor.  
Often a partial restriction of any type can be found by feel,  
as there is a temperature difference from one side of the  
restriction to the other.  
With a complete restriction, there will be no sound at the  
metering device entrance. An amperage check of the  
compressor with a partial restriction may show normal  
current when compared to the unit specification.  
23  
heRMeTIC COMPONeNTs CheCk  
WARNING  
BURN HAZARD  
WARNING  
Proper safety procedures must be followed,  
and proper protective clothing must be worn  
when working with a torch.  
CUT/SEVER HAZARD  
Be careful with the sharp edges and corners.  
Wear protective clothing and gloves, etc.  
Failure to follow these procedures could  
result in moderate or serious injury.  
Failure to do so could result in serious injury.  
MeTeRINg DeVICe  
Capillary Tube systems  
All units are equipped with capillary tube metering  
devices.  
3. Switch the unit to the heating mode and observe the  
gauge readings after a few minutes running time. If  
the system pressure is lower than normal, the heating  
capillary is restricted.  
Checking for restricted capillary tubes.  
1. Connect pressure gauges to unit.  
4. If the operating pressures are lower than normal in both  
the heating and cooling mode, the cooling capillary is  
restricted.  
2. Start the unit in the cooling mode. If after a few minutes  
of operation the pressures are normal, the check valve  
and the cooling capillary are not restricted.  
CheCk VALVe  
the port (liquid line) to the outdoor coil. The flow path of  
the refrigerant is then through the filter drier and heating  
capillary to the outdoor coil.  
A unique two-way check valve is used on the reverse cycle  
heat pumps. It is pressure operated and used to direct the  
flow of refrigerant through a single filter drier and to the  
proper capillary tube during either the heating or cooling  
cycle.  
Failure of the slide in the check valve to seat properly in  
either mode of operation will cause flooding of the cooling  
coil. This is due to the refrigerant bypassing the heating or  
cooling capillary tube and entering the liquid line.  
One-way Check Valve  
(Heat Pump Models)  
COOLING MODE  
In the cooling mode of operation, liquid refrigerant from  
condenser (liquid line) enters the cooling check valve  
forcing the heating check valve shut. The liquid refrigerant  
is directed into the liquid dryer after which the refrigerant  
is metered through cooling capillary tubes to evaporator.  
(Note: liquid refrigerant will also be directed through the  
heating capillary tubes in a continuous loop during the  
cooling mode).  
NOTE: The slide (check) inside the valve is made of teflon.  
Should it become necessary to replace the check valve,  
place a wet cloth around the valve to prevent overheating  
during the brazing operation.  
HEATING MODE  
In the heating mode of operation, liquid refrigerant from  
the indoor coil enters the heating check valve forcing the  
cooling check valve shut. The liquid refrigerant is directed  
into the liquid dryer after which the refrigerant is metered  
through the heating capillary tubes to outdoor coils. (Note:  
liquid refrigerant will also be directed through the cooling  
capillary tubes in a continuous loop during the heating  
mode).  
CHECK VALVE OPERATION  
In the cooling mode of operation, high pressure liquid enters  
the check valve forcing the slide to close the opposite port  
(liquid line) to the indoor coil. Refer to refrigerant flow chart.  
This directs the refrigerant through the filter drier and cooling  
capillary tube to the indoor coil.  
In the heating mode of operation, high pressure refrigerant  
enters the check valve from the opposite direction, closing  
24  
ReVeRsINg VALVe DesCRIPTION/OPeRATION  
of the system. The pilot section of the valve opens and  
WARNING  
ELECTRIC SHOCK HAZARD  
closes ports for the small capillary tubes to the main valve  
to cause it to shift.  
Disconnect power to the unit before servicing.  
Failure to follow this warning could result in  
serious injury or death.  
NOTE: System operating pressures must be near  
normal before valve can shift.  
The Reversing Valve controls the direction of refrigerant flow  
to the indoor and outdoor coils. It consists of a pressure-  
operated, main valve and a pilot valve actuated by a solenoid  
plunger. The solenoid is energized during the heating cycle  
only. The reversing valves used in the PTAC system is a  
2-position, 4-way valve.  
The single tube on one side of the main valve body is the  
high-pressure inlet to the valve from the compressor. The  
center tube on the opposite side is connected to the low  
pressure (suction) side of the system. The other two are  
connected to the indoor and outdoor coils. Small capillary  
tubes connect each end of the main valve cylinder to the “A”  
and “B” ports of the pilot valve. A third capillary is a common  
return line from these ports to the suction tube on the main  
valve body. Four-way reversing valves also have a capillary  
tube from the compressor discharge tube to the pilot valve.  
The piston assembly in the main valve can only be shifted  
by the pressure differential between the high and low sides  
TesTINg The COIL  
NOTE: Do not start unit with solenoid coil removed from  
valve, or do not remove coil after unit is in operation. This  
will cause the coil to burn out.  
WARNING  
ELECTRIC SHOCK HAZARD  
Unplug and/or disconnect all electrical power  
to the unit before performing inspections,  
maintenances or service.  
CheCkINg The ReVeRsINg VALVe  
NOTE: You must have normal operating pressures before  
Failure to do so could result in electric shock,  
serious injury or death.  
the reversing valve can shift.  
WARNING  
The solenoid coil is an electromagnetic type coil mounted  
on the reversing valve and is energized during the  
operation of the compressor in the heating cycle.  
HIGH PRESSURE HAZARD  
Sealed Refrigeration System contains refrigerant  
and oil under high pressure.  
1. Turn off high voltage electrical power to unit.  
Proper safety procedures must be followed,  
and proper protective clothing must be worn  
when working with refrigerants.  
2. Unplug line voltage lead from reversing valve coil.  
3. Check for electrical continuity through the coil. If you  
Failure to follow these procedures could  
result in serious injury or death.  
do not have continuity replace the coil.  
4. Check from each lead of coil to the copper liquid line  
as it leaves the unit or the ground lug. There should  
be no continuity between either of the coil leads  
and ground; if there is, coil is grounded and must be  
replaced.  
Check the operation of the valve by starting the system  
and switching the operation from “Cooling” to “Heating”  
and then back to “Cooling”. Do not hammer on valve.  
Occasionally, the reversing valve may stick in the heating  
or cooling position or in the mid-position.  
5. If coil tests okay, reconnect the electrical leads.  
6. Make sure coil has been assembled correctly.  
25  
When sluggish or stuck in the mid-position, part of the  
discharge gas from the compressor is directed back to the  
suction side, resulting in excessively high suction pressure.  
Touch Test in heating/Cooling Cycle  
WARNING  
BURN HAZARD  
Certain unit components operate at  
temperatures hot enough to cause burns.  
Should the valve fail to shift from coooling to heating,  
block the air flow through the outdoor coil and allow the  
discharge pressure to build in the system. Then switch the  
system from heating to cooling.  
Proper safety procedures must be followed,  
and proper protective clothing must be  
worn.  
If the valve is stuck in the heating position, block the air  
flow through the indoor coil and allow discharge pressure  
to build in the system. Then switch the system from heating  
to cooling.  
Failure to follow these procedures could  
result in minor to moderate injury.  
Shouldthevalvefailtoshiftineitherpositionafterincreasing  
the discharge pressure, replace the valve.  
The only definite indications that the slide is in the mid-  
position is if all three tubes on the suction side of the valve  
are hot after a few minutes of running time.  
Dented or damaged valve body or capillary tubes can  
prevent the main slide in the valve body from shifting.  
NOTE: A condition other than those illustrated above, and  
on Page 31, indicate that the reversing valve is not shifting  
properly. Both tubes shown as hot or cool must be the same  
corresponding temperature.  
If you determing this is the problem, replace the reversing  
valve.  
Procedure For Changing Reversing Valve  
After all of the previous inspections and checks have been  
made and determined correct, then perform the “Touch  
Test” on the reversing valve.  
WARNING  
HIGH PRESSURE HAZARD  
SealedRefrigerationSystemcontainsrefrigerant  
and oil under high pressure.  
Proper safety procedures must be followed,  
and proper protective clothing must be worn  
when working with refrigerants.  
Failure to follow these procedures could  
result in serious injury or death.  
NOTICE  
FIRE HAZARD  
The use of a torch requires extreme care and proper  
judgment. Follow all safety recommended precautions  
and protect surrounding areas with fire proof materials.  
Have a fire extinguisher readily available. Failure to follow  
this notice could result in moderate to serious property  
damage.  
Reversing Valve in Heating Mode  
1. Install Process Tubes. Recover refrigerant from sealed  
system. PROPER HANDLING OF RECOVERED  
REFRIGERANT ACCORDING TO EPA REGULATIONS  
IS REQUIRED.  
2. Remove solenoid coil from reversing valve. If coil is to  
be reused, protect from heat while changing valve.  
3. Unbraze all lines from reversing valve.  
4. Clean all excess braze from all tubing so that they will  
slip into fittings on new valve.  
5. Remove solenoid coil from new valve.  
Reversing Valve in Cooling Mode  
26  
6. Protectnewvalvebodyfromheatwhilebrazingwith plastic  
heat sink (Thermo Trap) or wrap valve body with wet  
rag.  
Determine L.R.V.  
Start the compressor with the volt meter attached; then stop  
the unit. Attempt to restart the compressor within a couple  
of seconds and immediately read the voltage on the meter.  
The compressor under these conditions will not start and will  
usually kick out on overload within a few seconds since the  
pressures in the system will not have had time to equalize.  
Voltage should be at or above minimum voltage of 197 VAC,  
as specified on the rating plate. If less than minimum, check  
for cause of inadequate power supply; i.e., incorrect wire  
size, loose electrical connections, etc.  
7. Fit all lines into new valve and braze lines into new  
valve.  
WARNING  
EXPLOSION HAZARD  
The use of nitrogen requires a pressure  
regulator. Follow all safety procedures and  
wear protective safety clothing etc.  
Amperage (L.R.A.) Test  
Failure to follow proper safety procedures  
could result in serious injury or death.  
The running amperage of the compressor is the most impor-  
tant of these readings. A running amperage higher than that  
indicated in the performance data indicates that a problem  
exists mechanically or electrically.  
8. Pressurize sealed system with a combination of R-22  
and nitrogen and check for leaks, using a suitable leak  
detector. Recover refrigerant per EPA guidelines.  
Single Phase Running and L.R.A. Test  
NOTE: Consult the specification and performance section  
for running amperage. The L.R.A. can also be found on the  
rating plate.  
9. Once the sealed system is leak free, install solenoid coil  
on new valve and charge the sealed system by weighing  
in the proper amount and type of refrigerant as shown  
on rating plate. Crimp the process tubes and solder the  
ends shut. Do not leave Schrader or piercing valves in  
the sealed system.  
Select the proper amperage scale and clamp the meter  
probe around the wire to the “C” terminal of the compressor.  
Turn on the unit and read the running amperage on the me-  
ter. If the compressor does not start, the reading will indicate  
the locked rotor amperage (L.R.A.).  
NOTE: When brazing a reversing valve into the system, it is  
of extreme importance that the temperature of the valve does  
not exceed 250°F at any time.  
Overloads  
The compressor is equipped with an external or internal  
overload which senses both motor amperage and winding  
temperature. High motor temperature or amperage heats  
the overload causing it to open, breaking the common circuit  
within the compressor.  
Wrap the reversing valve with a large rag saturated with  
water. “Re-wet” the rag and thoroughly cool the valve after  
each brazing operation of the four joints involved.  
The wet rag around the reversing valve will eliminate  
conduction of heat to the valve body when brazing the line  
connection.  
Heat generated within the compressor shell, usually due to  
recycling of the motor, is slow to dissipate. It may take any-  
where from a few minutes to several hours for the overload  
to reset.  
COMPRessOR CheCks  
Checking the Overload  
WARNING  
ELECTRIC SHOCK HAZARD  
Turn off electric power before service or  
installation. Extreme care must be used, if it  
becomes necessary to work on equipment with  
power applied.  
WARNING  
ELECTRIC SHOCK HAZARD  
Turn off electric power before service or  
installation. Extreme care must be used, if it  
becomes necessary to work on equipment  
with power applied.  
Failure to do so could result in serious injury or  
death.  
Locked Rotor Voltage (L.R.V.) Test  
Failure to do so could result in serious injury or  
death.  
Locked rotor voltage (L.R.V.) is the actual voltage available  
at the compressor under a stalled condition.  
single Phase Connections  
Disconnect power from unit. Using a voltmeter, attach one  
lead of the meter to the run “R” terminal on the compressor  
and the other lead to the common “C” terminal of the com-  
pressor. Restore power to unit.  
27  
Add values “C” to “S” and “C” to “R” together and check  
resistancefromstarttorunterminals(“S”to“R”). Resistance  
“S” to “R” should equal the total of “C” to “S” and “C” to “R.”  
WARNING  
BURN HAZARD  
Certain unit components operate at  
temperatures hot enough to cause burns.  
In a single phase PSC compressor motor, the highest  
value will be from the start to the run connections (“S” to  
“R”). The next highest resistance is from the start to the  
common connections (“S” to “C”). The lowest resistance  
is from the run to common. (“C” to “R”) Before replacing a  
compressor, check to be sure it is defective.  
Proper safety procedures must be followed,  
and proper protective clothing must be  
worn.  
Failure to follow this warning could result  
in moderate to serious injury.  
external Overload VPAk 9, 12, 18 k Btus  
With power off, remove the leads from compressor termi-  
nals. If the compressor is hot, allow the overload to cool  
before starting check. Using an ohmmeter, test continu-  
ity across the terminals of the external overload. If you  
do not have continuity; this indicates that the overload is  
open and must be replaced.  
Internal Overload VPAk 24 k Btus  
The overload is embedded in the motor windings to  
sense the winding temperature and/or current draw. The  
overload is connected in series with the common motor  
terminal.  
GROUND TEST  
Use an ohmmeter set on its highest scale. Touch one  
lead to the compressor body (clean point of contact as a  
good connection is a must) and the other probe in turn  
to each compressor terminal. If a reading is obtained the  
compressor is grounded and must be replaced.  
1. With no power to unit, remove the leads from the com-  
pressor terminals. Allow motor to cool.  
2. Using an ohmmeter, test continuity between terminals  
C-S and C-R. If no continuity, the compressor overload is  
open and the compressor must be replaced.  
Check the complete electrical system to the compressor  
and compressor internal electrical system, check to be  
certain that compressor is not out on internal overload.  
Completeevaluationofthesystemmustbemadewhenever  
you suspect the compressor is defective. If the compressor  
has been operating for sometime, a careful examination  
must be made to determine why the compressor failed.  
Internal Overload  
Many compressor failures are caused by the following  
conditions:  
1. Improper air flow over the evaporator.  
single Phase Resistance Test  
2. Overcharged refrigerant system causing liquid to be  
returned to the compressor.  
WARNING  
ELECTRIC SHOCK HAZARD  
3. Restricted refrigerant system.  
Turn off electric power before service or  
installation. Extreme care must be used, if it  
becomes necessary to work on equipment  
with power applied.  
4. Lack of lubrication.  
5. Liquid refrigerant returning to compressor causing oil  
Failure to do so could result in serious injury or  
death.  
to be washed out of bearings.  
6.  
Noncondensables such as air and moisture in  
the system. Moisture is extremely destructive to a  
refrigerant system.  
Remove the leads from the compressor terminals and set  
the ohmmeter on the lowest scale (R x 1).  
Touch the leads of the ohmmeter from terminals common  
to start (“C” to “S”). Next, touch the leads of the ohmmeter  
from terminals common to run (“C” to “R”).  
28  
COMPRessOR RePLACeMeNT  
Recommendedprocedure forcompressor  
replacement  
3. After all refrigerant has been recovered, disconnect  
suction and discharge lines from the compressor and  
remove compressor. Be certain to have both suction  
and discharge process tubes open to atmosphere.  
WARNING  
4. Carefully pour a small amount of oil from the suction  
RISK OF ELECTRIC SHOCK  
Unplug and/or disconnect all electrical power  
to the unit before performing inspections,  
maintenances or service.  
stub of the defective compressor into a clean  
container.  
5. Using an acid test kit (one shot or conventional kit), test  
the oil for acid content according to the instructions  
with the kit.  
Failure to do so could result in electric shock,  
serious injury or death.  
6. If any evidence of a burnout is found, no matter how  
slight, the system will need to be cleaned up following  
proper procedures.  
1. Be certain to perform all necessary electrical and  
refrigeration tests to be sure the compressor is  
actually defective before replacing.  
7. Install the replacement compressor.  
WARNING  
WARNING  
HIGH PRESSURE HAZARD  
SealedRefrigerationSystemcontainsrefrigerant  
and oil under high pressure.  
EXPLOSION HAZARD  
The use of nitrogen requires a pressure  
regulator. Follow all safety procedures and  
wear protective safety clothing etc.  
Proper safety procedures must be followed,  
and proper protective clothing must be worn  
when working with refrigerants.  
Failure to follow proper safety procedures  
result in serious injury or death.  
Failure to follow these procedures could  
result in serious injury or death.  
8. Pressurize with a combination of R-410A and nitrogen  
and leak test all connections with leak detector capable of  
detecting HFC (Hydrofluorocarbon) refrigerant. Recover  
refrigerant/nitrogen mixture and repair any leaks found.  
2. Recover all refrigerant from the system though  
the process tubes. PROPER HANDLING OF  
RECOVERED REFRIGERANT ACCORDING TO  
EPA REGULATIONS IS REQUIRED. Do not use  
gauge manifold for this purpose if there has been  
a burnout. You will contaminate your manifold and  
hoses. Use a Schrader valve adapter and copper  
tubing for burnout failures.  
Repeat Step 8 to insure no more leaks are present.  
9. Evacuate the system with a good vacuum pump capable  
of a final vacuum of 200 microns or less. The system  
should be evacuated through both liquid line and suction  
line gauge ports. While the unit is being evacuated, seal  
all openings on the defective compressor.  
WARNING  
HIGH TEMPERATURES  
CAUTION  
FREEZE HAZARD  
Extreme care, proper judgment and all safety  
procedures must be followed when testing,  
troubleshooting, handling or working around  
unit while in operation with high temperature  
components. Wear protective safety aids  
such as: gloves, clothing etc.  
Proper safety procedures must be followed,  
and proper protective clothing must be worn  
when working with liquid refrigerant.  
Failure to follow these procedures could  
result in minor to moderate injury.  
Failure to do so could result in serious burn  
injury.  
10. Recharge the system with the correct amount of  
refrigerant. The proper refrigerant charge will be  
found on the unit rating plate. The use of an accurate  
measuring device, such as a charging cylinder,  
NOTICE  
FIRE HAZARD  
electronic scales or similar device is necessary.  
The use of a torch requires extreme care and proper  
judgment. Follow all safety recommended precautions  
and protect surrounding areas with fire proof materials.  
Have a fire extinguisher readily available. Failure to follow  
this notice could result in moderate to serious property  
damage.  
NOTICE  
NEVER, under any circumstances, charge a rotary  
compressor through the LOW side. Doing so would  
cause permanent damage to the new compressor.  
29  
SPECIAL PROCEDURE IN THE CASE OF MOTOR  
COMPRESSOR BURNOUT  
To ensure proper unit operation and life expectancy, the  
following maintenance procedures should be performed  
on a regular basis  
WARNING  
ELECTRIC SHOCK HAZARD  
Turn off electric power before service or  
installation.  
1. Air Filter  
To ensure proper unit operation, the air filters should  
be cleaned at least monthly, and more frequently if  
conditions warrant. The unit must be turned off before  
the filters are cleaned.  
Failure to do so may result in personal injury,  
or death.  
To remove the air filters, grasp the top of the filter and lift  
out of the front cabinet. Reverse the procedure to reinstall  
the filters.  
WARNING  
HIGH PRESSURE HAZARD  
Clean the filters with a mild detergent in warm water, and  
allow them to dry thoroughly before reinstalling.  
SealedRefrigerationSystemcontainsrefrigerant  
and oil under high pressure.  
2. Coils & Chassis  
Proper safety procedures must be followed,  
and proper protective clothing must be worn  
when working with refrigerants.  
NOTE: Do not use a caustic coil cleaning agent on coils  
or base pan. Use a biodegradable cleaning agent and  
degreaser. The use of harsh cleaning materials may  
lead to deterioration of the aluminum fins or the coil end  
plates.  
Failure to follow these procedures could  
result in serious injury or death.  
The indoor coil and outdoor coils and base pan should  
be inspected periodically (annually or semi-annually)  
and cleaned of all debris (lint, dirt, leaves, paper, etc.)  
as necessary. Under extreme conditions, more frequent  
cleaning may be required. Clean the coils and base  
pan with a soft brush and compressed air or vacuum.  
A pressure washer may also be used, however, you  
must be careful not to bend the aluminum fin pack. Use  
a sweeping up and down motion in the direction of the  
vertical aluminum fin pack when pressure cleaning coils.  
WARNING  
EXPLOSION HAZARD  
The use of nitrogen requires a pressure  
regulator. Follow all safety procedures and  
wear protective safety clothing etc.  
Failure to follow proper safety procedures  
result in serious injury or death.  
1.  
Recover all refrigerant and oil from the system.  
Note: It is extremely important to insure that none of the  
electrical and/or electronic parts of the unit get wet. Be  
sure to cover all electrical components to protect them  
from water or spray.  
Remove compressor, capillary tube and filter drier  
from the system.  
2.  
3.  
Flush evaporator condenser and all connecting  
tubing with dry nitrogen or equivalent. Use approved  
flushing agent to remove all contamination from  
system. Inspect suction and discharge line for  
carbon deposits. Remove and clean if necessary.  
Ensure all acid is neutralized.  
3. Decorative Front  
The decorative front and discharge air grille may be  
cleaned with a mild soap or detergent. Do NOT use  
solvents or hydrocarbon based cleaners such as  
acetone, naphtha, gasoline, benzene, etc., to clean the  
decorative front or air discharge grilles.  
4. Reassemble the system, including new drier strainer  
and capillary tube.  
Use a damp (not wet) cloth when cleaning the control  
area to prevent water from entering the unit, and possibly  
damaging the electronic control  
5. Proceed with step 8-10 on previous page.  
4. Fan Motor & Compressor  
The fan motor & compressor and are permanently  
lubricated, and require no additional lubrication.  
ROUTINe MAINTeNANCe  
WARNING  
5. Wall Sleeve  
Inspect the inside of the wall sleeve and drain system  
periodically (annually or semi-annually) and clean as  
required. Under extreme conditions, more frequent  
cleaning may be necessary. Clean both of these areas  
with an antibacterial and antifungal cleaner. Rinse both  
items thoroughly with water and ensure that the drain  
outlets are operating properly.  
ELECTRICAL SHOCK HAZARD!  
Turn off electrical power before service or  
installation. All eletrical connections and wiring  
MUST be installed by a qualified electrician  
and conform to the National Code and all local  
codes which have jurisdiction. Failure to do so  
can result in property damage, personal injury  
and/or death.  
30  
eLeCTRICAL TROUBLeshOOTINg ChART - COOLINg  
9k BTU, 12k BTU, & 18k BTU  
NO COOLING OPERATION  
Before continuing  
check for Error  
Insure that Fuses  
are good and/or that  
Circuit Breakers are  
on and voltage is 208/230  
Codes, see  
electronics control  
diagnostics and  
test mode, page 15  
O.K.  
Set thermostat to  
"Cool," and the Temp.  
below the present  
Room Temp.  
Nothing operates,  
entire system  
appears dead  
Yes  
No  
O.K.  
Check Supply Circuit’s  
jumper at transformer. If  
okay, replace board  
Line voltage present  
at the Transformer  
Primary  
Compressor and Fan  
Motor should now  
operate  
Compressor runs but  
Blower/Fan doesn't  
Fan runs but  
Compressor doesn't  
No  
No  
Yes  
Yes  
Yes  
Yes  
Problems indicated with  
Control Transformer  
replace board  
24 Volts at  
See Refrigerant Circuit  
diagnosis if unit still is  
not cooling properly  
“R” Terminal on board  
No  
No  
Yes  
24 Volts present at  
Y terminals on  
t-stat and board?  
Problems indicated with  
Room Thermostat or  
Control Wiring  
Yes  
208/230 Volts present  
at #1 relay on board?  
Replace board  
Yes  
Defective t-stat  
defective control wiring  
or transformer  
24V at t-stat and  
control wiring?  
No  
No  
Yes  
Yes  
Compressor and fan  
motor should now  
operate  
No  
Yes  
Problems indicated  
in Blower Relay  
of board  
Is Line Voltage present  
at Motor Leads?  
No  
Supply Circuit  
problems, loose  
Connections, or bad  
Relays/Board  
Is Locked Rotor  
See Refrigerant  
Circuit Diagnosis if  
unit still is not cooling  
properly  
Yes  
Voltage a minimum of  
197 Volts?  
No  
No  
Yes  
Check Capacitor, is  
Capacitor Good?  
Replace Capacitor  
No  
No  
Replace Capacitor  
and/or Start Assist  
Device  
Are Capacitor and (if  
so equipped) Start  
Assist good?  
Yes  
Possible motor  
problem indicated.  
Check motor  
Yes  
Motor should run  
thoroughly  
Allow ample time  
for pressures to  
equalize  
Have System  
Pressures Equalized?  
No  
No  
Yes  
Possible Compressor  
problem indicated.  
See Compressor  
Checks  
Compressor should  
run  
31  
eLeCTRICAL TROUBLeshOOTINg ChART - COOLINg  
24k BTU  
NO COOLING OPERATION  
Before continuing  
check for Error  
Insure that Fuses  
are good and/or that  
Circuit Breakers are  
on and voltage is 208/230  
Codes, see  
electronics control  
diagnostics and  
test mode, page 15  
O.K.  
Set thermostat to  
"Cool," move the Temp.  
lever below the present  
Room Temp.  
Nothing operates,  
entire system  
appears dead  
Yes  
No  
O.K.  
Check Supply Circuit’s  
jumper at transformer. If  
okay, replace board  
Line voltage present  
at the Transformer  
Primary  
Compressor outdoor  
fan motor and indoor  
blower should now  
operate  
Compressor and outdoor  
fan motor run but indoor  
blower does not run  
Indoor blower runs but  
outdoor fan motor and  
compressor do not run  
No  
No  
No  
No  
Yes  
Yes  
Yes  
Yes  
Problems indicated with  
Control Transformer  
replace board  
24 Volts at  
“R” Terminal on board  
See Refrigerant Circuit  
diagnosis if unit still is  
not cooling properly  
Yes  
Yes  
24 Volts present at  
Y terminals on  
t-stat and board?  
Problems indicated with  
Room Thermostat or  
Control Wiring  
Yes  
Yes  
208/230 Volts present  
at #1 relay and “OD”  
terminal on board?  
Replace board  
Defective t-stat  
defective control wiring  
or transformer  
24V at t-stat and  
control wiring?  
No  
No  
No  
Yes  
Yes  
208/230 Volts present  
at compressor’s  
contactor?  
Check contactor  
If defective replace  
Yes  
Yes  
Compressor and  
outdoor fan motor  
should now operate  
No  
Problems indicated  
in Blower Relay  
of board  
Yes  
Is Line Voltage present  
at Motor Leads?  
No  
Supply Circuit  
problems, loose  
Connections, or bad  
Relays/Board  
Is Locked Rotor  
See Refrigerant  
Circuit Diagnosis  
if unit still is not  
cooling properly  
Yes  
Voltage a minimum of  
197 Volts?  
No  
No  
Yes  
Check Capacitor, is  
Capacitor Good?  
Replace Capacitor  
No  
No  
Replace Capacitor  
and/or Start Assist  
Device  
Are Capacitor and (if  
so equipped) Start  
Assist good?  
Yes  
Possible motor  
problem indicated.  
Check motor  
Yes  
Motor should run  
thoroughly  
Allow ample time  
for pressures to  
equalize  
Have System  
Pressures Equalized?  
No  
No  
Yes  
Possible Compressor  
problem indicated.  
See Compressor  
Checks  
Compressor should  
run  
32  
eLeCTRICAL TROUBLeshOOTINg ChART  
heAT PUMP  
HEAT PUMP MODE  
SYSTEM COOLS WHEN  
HEATING IS DESIRED.  
Is Line Voltage  
Present at  
Solenoid Valve?  
NO  
Is Selector Switch  
set for Heat?  
YES  
NO  
Is the Solenoid  
Coil Good?  
Replace Solenoid Coil  
YES  
Reversing Valve Stuck  
YES  
Replace Reversing Valve  
33  
TROUBLeshOOTINg ChART - COOLINg  
REFRIGERANT SYSTEM DIAGNOSIS COOLING  
PROBLEM  
PROBLEM  
PROBLEM  
PROBLEM  
LOW SUCTION PRESSURE  
HIGH SUCTION PRESSURE  
LOW HEAD PRESSURE  
HIGH HEAD PRESSURE  
Low Load Conditions  
High Load Conditions  
Low Load Conditions  
High Load Conditions  
Low Air Flow Across  
Indoor Coil  
High Air Flow Across  
Indoor Coil  
Refrigerant System  
Restriction  
Low Air Flow Across  
Outdoor Coil  
Refrigerant System  
Restriction  
Reversing Valve not  
Fully Seated  
Reversing Valve not  
Fully Seated  
Overcharged  
Undercharged  
Overcharged  
Non-Condensables (air)  
Undercharged System  
Defective Compressor  
Moisture in System  
Defective Compressor  
TROUBLeshOOTINg ChART - heATINg  
REFRIGERANT SYSTEM DIAGNOSIS HEATING  
PROBLEM  
PROBLEM  
PROBLEM  
PROBLEM  
LOW SUCTION PRESSURE  
HIGH SUCTION PRESSURE  
LOW HEAD PRESSURE  
HIGH HEAD PRESSURE  
Low Air Flow Across  
Outdoor Coil  
Outdoor Ambient Too High  
for Operation in Heating  
Refrigerant System  
Restriction  
Outdoor Ambient Too High  
For Operation In Heating  
Refrigerant System  
Restriction  
Reversing Valve not  
Fully Seated  
Reversing Valve not  
Fully Seated  
Low Air Flow Across  
Indoor Coil  
Undercharged  
Overcharged  
Undercharged  
Overcharged  
Non-Condensables (air)  
in System  
Moisture in System  
Defective Compressor  
Defective Compressor  
34  
COOL wITh eLeCTRIC heAT  
eLeCTRICAL & TheRMOsTAT wIRINg DIAgRAM  
VeA 09/12/18 with 2.5 kw, 3.4 kw or 5kw  
eLeCTRIC heAT  
NOTE:  
THE DIAGRAM ABOVE, ILLUSTRATES THE TYPICAL THERMOSTAT WIRING FOR TWO SPEED  
FAN OPERATION. SEE THE UNIT CONTROL PANEL FOR THE ACTUAL UNIT WIRING DIAGRAM  
AND SCHEMATIC.  
35  
heAT PUMP wITh eLeCTRIC heAT  
eLeCTRICAL & TheRMOsTAT wIRINg DIAgRAM  
VhA 09/12/18 with 2.5 kw, 3.4 kw or 5kw  
eLeCTRIC heAT  
NOTE:  
THE DIAGRAM ABOVE, ILLUSTRATES THE TYPICAL THERMOSTAT WIRING FOR TWO SPEED  
FAN OPERATION. SEE THE UNIT CONTROL PANEL FOR THE ACTUAL UNIT WIRING DIAGRAM  
AND SCHEMATIC.  
36  
COOL wITh eLeCTRIC heAT  
eLeCTRICAL & TheRMOsTAT wIRINg DIAgRAM  
VeA 24 with 2.5 kw, 3.4 kw or 5kw eLeCTRIC heAT  
37  
heAT PUMP wITh eLeCTRIC heAT  
eLeCTRICAL & TheRMOsTAT wIRINg DIAgRAM  
VhA 24 with 2.5 kw, 3.4 kw or 5kw eLeCTRIC heAT  
38  
COOL wITh eLeCTRIC heAT  
eLeCTRICAL & TheRMOsTAT wIRINg DIAgRAM  
VeA 24 with 7.5 kw and 10 kw eLeCTRIC heAT  
39  
heAT PUMP wITh eLeCTRIC heAT  
eLeCTRICAL & TheRMOsTAT wIRINg DIAgRAM  
VhA 24 with 7.5 kw and 10kw eLeCTRIC heAT  
40  
TeChNICAL seRVICe DATA  
INDOOR COIL  
TEMPERATURE  
º F  
ELECTRICAL  
RATINGS  
OPERATING  
PRESSURES  
Refrigerant  
Charge  
OUTDOOR COIL Discharge Line Suction Line  
SERVICE DATA  
Cooling¹  
TEMPERATURE  
º F  
Temperature  
º F  
Temperature Super Heat Sub-Cooling  
º F  
Temperature  
Voltage  
Amps Supply Air  
Suction Discharge R-410A - Oz.  
Drop ¨  
22  
VEA09K**RTL  
VEA12K**RTL  
VEA18K**RTL  
VEA24K**RTL  
VHA09K**RTL  
VHA12K**RTL  
VHA18K**RTL  
VHA24K**RTL  
230/208  
230/208  
230/208  
230/208  
230/208  
230/208  
230/208  
230/208  
4.2  
5.2  
58  
57  
55  
55  
57  
55  
51  
51  
118  
116  
127  
125  
117  
119  
129  
128  
156  
158  
180  
170  
155  
165  
190  
174  
66  
59  
60  
61  
62  
65  
60  
60  
9
24  
17  
28  
34  
20  
23  
35  
32  
151  
141  
135  
135  
155  
145  
133  
140  
389  
396  
455  
440  
405  
450  
465  
480  
33.5  
32.0  
48.0  
65.0  
39.0  
42.0  
45.0  
74.0  
23  
12  
12  
10  
12  
15  
14  
12  
8.1  
25  
10.0  
4.1  
25  
23  
5.3  
25  
8.2  
10.6  
29  
29  
¹Test Conditions: 80º F, Room Air Temperature with 50% Relative Humidity, and 95º F, Outdoor Air Temperature with 40% Relative Humidity  
**Denotes Heater KW - Numbers Vary  
41  
TECHNICAL SUPPORT  
CONTACT INFORMATION  
FRIEDRICH AIR CONDITIONING CO.  
Post Office Box 1540 · San Antonio, Texas 78295-1540  
4200 N. Pan Am Expressway · San Antonio, Texas 78218-5212  
(210) 357-4400 · 1-800-541-6645 · FAX (210) 357-4490  
www.friedrich.com  
Printed in the U.S.A.  
VPK-ServMan-L (1-10)  
Printed in the U.S.A.  
FRIEDRICH AIR CONDITIONING CO.  
Post Office Box 1540 · San Antonio, Texas 78295-1540  
4200 N. Pan Am Expressway · San Antonio, Texas 78218-5212  
(210) 357-4400 · FAX (210) 357-4490  
www.friedrich.com  
VPK-ServMan-L (1-10)  
Printed in the U.S.A.  

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