Friedrich H)A09K25 User Manual

Service Manual

A SERIES

Single Package
Vertical Air Conditioning System
A – H Suffi x Models

MODELS
V(E,H)A09K25*** V(E,H)A09K34*** V(E,H)A09K50***
V(E,H)A12K25*** V(E,H)A12K34*** V(E,H)A12K50***
V(E,H)A18K25*** V(E,H)A18K34*** V(E,H)A18K25***
V(E,H)A24K25*** V(E,H)A24K34*** V(E,H)A24K50***
V(E,H)A24K75*** V(E,H)A24K10*** V(E,H)A24K00***

VPSERVMN (4-05)

*** Digits vary with model.

Table of Contents

Introduction ......................................................................3

Vert-I-Pak Model Number Identifi cation Guide ..............4

Serial Number Identifi cation Guide .................................4

H Suffi x Chassis Specifi cations ......................................5

E and G Suffi x Chassis Specifi cations ............................6

A and D Suffi x Chassis Specifi cations ............................7

Sequence Of Operation ................................................... 8

Electrical Supply ..............................................................9

Supply Circuit ...................................................................9

Supply Voltage .................................................................9

Control (Low) Voltage ......................................................9

Supply Voltage .................................................................9

Electrical Ground .............................................................9

Electrical Rating Tables ...................................................9

Undercharged Refrigerant Systems ..............................17

Overcharged Refrigerant Systems ................................18

Restricted Refrigerant Systems .....................................18

Capillary Tube Systems .................................................19

Reversing Valve — Description/Operation ...................19

Electrical Circuit And Coil ..............................................19

Testing Coil ....................................................................19

Checking Reversing Valves ...........................................20

Touch Testing Heating/Cooling Cycle ..........................20

Procedure For Changing Reversing Valve ....................20

Compressor Checks ......................................................21

Locked Rotor Voltage Test ............................................21

Single Phase Connections ...........................................21

Determine Locked Rotor Voltage .................................21

Electrical Requirements ...................................................9

Room Thermostats ........................................................10

Thermostat Location ......................................................10

Heat Anticipators ..........................................................10

Electrical & Thermostat Wiring Diagrams ................ 11-13

Indoor Blower - Air Flow ................................................14

Condenser Fan Motors ..................................................14

Blower Wheel Inspection ...............................................14

Cooling ........................................................................... 14

Heating (Electric) ..........................................................14

External Static Pressure ................................................14

Checking External Static Pressure ...............................15

Checking Approximate Airfl ow ...................................... 15

Electric Heat Strips ........................................................15

Locked Rotor Amperage Test ........................................21

Single Phase Running & Locked Rotor Amperage .......21

External Overload ..........................................................21

Checking the External Overload ...................................21

Checking the Internal Overload .....................................21

Compressor Single Phase Resistance Test .................22

Compressor Replacement .............................................22

Capacitors ...................................................................... 23

Capacitor Check With Capacitor Analyzer ....................23

Capacitor Connections ..................................................23

Emergency Heat Switch ................................................24

Wiring Diagram Index .............................................. 25-26

9-18 Electrical Troubleshooting Chart – Cooling .........39

2-Ton Electrical Troubleshooting Chart – Cooling .......40

Airfl ow Charts ................................................................16

Refrigerant Charging .....................................................16

Method Of Charging ......................................................17

2

Refrigerant System Diagnosis – Cooling ......................41

Refrigerant System Diagnosis – Heating ...................... 41

Electrical Troubleshooting Chart –Heat Pump .............42

Introduction

This service manual is designed to be used in conjunction with the installation manuals provided with each air
conditioning system component. Air conditioning systems consist of BOTH an evaporator (indoor section) and a
condenser (outdoor section) in one closed system, and a room thermostat. When so equipped, accessories such as
electric strip heaters are also considered part of the system.
This service manual was written to assist the professional HVAC service technician to quickly and accurately diagnose
and repair any malfunctions of this product.

This manual, therefore, will deal with all subjects in a general nature. (i.e. All text will pertain to all models).

IMPORTANT: It will be necessary for you to accurately identify the unit you are

servicing, so you can be certain of a proper diagnosis and repair.
(See Unit Identifi cation.)

WARNING

The information contained in this manual is intended for use by a qualifi ed service technician who is familiar

with the safety procedures required in installation and repair, and who is equipped with the proper tools and

test instruments.

Installation or repairs made by unqualifi ed persons can result in hazards subjecting the unqualifi ed person

making such repairs to the risk of injury or electrical shock which can be serious or even fatal not only to them,

but also to persons being served by the equipment.

If you install or perform service on equipment, you must assume responsibility for any bodily injury or property

damage which may result to you or others. Friedrich Air Conditioning Company will not be responsible for any

injury or property damage arising from improper installation, service, and/or service procedures.

3

Model Identifi cation Guide

MODEL NUMBER V E A 24 K 50 RT A

SERIES

V=Vertical Series

E=Cooling with or without electric heat

H=Heat Pump

DESIGN SERIES

A = 32" and 47" Cabinet

NOMINAL CAPACITY

A-Series (Btu/h)

09 = 9,000

12 = 12,000

18 = 18,000

24 = 24,000

VOLTAGE

K = 208/230V-1Ph-60Hz

Serial Number Identifi cation Guide

SERIAL NUMBER

L K A V 00001

Decade Manufactured

J = 9 K = Not Used
L = 0

YEAR MANUFACTURED

A = 1 E = 5 J = 9
B = 2 F = 6 K = 0
C = 3 G = 7
D = 4 H = 8

PRODUCTION RUN NUMBER

PRODUCT LINE

R = RAC
P = PTAC
E = EAC
V = VPAK
H = SPLIT

EN GI NEER ING CODE

OPTIONS

RT = Stan dard Re mote Op er a tion
SP = Sea coast Pro tect ed

ELECTRIC HEATER SIZE
A-Series

00 = No electric heat
25 = 2.5 KW
34 = 3.4 KW
50 = 5.0 KW
75 = 7.5 KW
10 = 10 KW

MONTH MANUFACTURED

A = Jan D = Apr G = Jul K = Oct
B = Feb E = May H = Aug L = Nov
C = Mar F = Jun J = Sep M = Dec

4

VERT-I-PAK® H SUFFIX CHASSIS SPECIFICATIONS

VEA/VHA9K-24K

VEA09K VEA12K VEA18K VEA24K VHA09K VHA12K VHA18K VHA24K

COOLING DATA

Cooling Btu/h 9500/9300 11800/11500 18000/17800 24000 9500/9300 11800/11500 18000/17800 23500

Cooling Power (W) 880 1093 2070 2526 905 1124 2070 2474

EER 10.8 10.8 8.7 9.5 10.5 10.5 8.7 9.5

Sensible Heat Ratio 0.74 0.72 0.70 0.70 0.74 0.72 0.70 0.70

HEAT PUMP DATA

Heating Btu/h N/A N/A N/A N/A 8500/8300 10600/10400 15700/15500 22500
COP @ 47°F N/A N/A N/A N/A 3.0 3.2 3.0 3

Heating Power (W) N/A N/A N/A N/A 830 971 1705 2200

Heating Current (A) N/A N/A N/A N/A 4.4/4.9 5.5/6.1 9.2/10.2 11.4

ELECTRICAL DATA

Voltage (1 Phase, 60 Hz) 230/208 230/208 230/208 230/208 230/208 230/208 230/208 230/208

Volt Range 253-198 253-198 253-198 253-198 253-198 253-198 253-198 253-198

Cooling Current (A) 4.1/4.3 4.9/5.3 9.2/10.2 11.2/12.4 4.2/4.4 5.0/5.5 9.2/10.2 11.2/12.4

Amps L.R. 21 21 47 68 21 21 47 68

Amps F.L. 3.7 4.5 7.9 10.2 3.7 4.5 7.9 10.2

Indoor Motor (HP) 1/4 1/4 1/4 1/4 1/4 1/4 1/4 1/4

Indoor Motor (A) 1.2 1.2 1.4 2 1.2 1.2 1.4 2

Outdoor Motor (HP) N/A N/A N/A 1/4 N/A N/A N/A 1/4

Outdoor Motor (A) N/A N/A N/A 2 N/A N/A N/A 2

AIRFLOW DATA

Indoor CFM* 300 350 550 750 300 375 550 750

Vent CFM 60 60 60 80 60 60 60 80
Max. ESP .3" .3" .3" .3" .3" .3" .3" .3"

PHYSICAL DATA

Dimensions (W x D x H) 23 x 23 x 32 23 x 23 x 32 23 x 23 x 32 23 x 23 x 47 23 x 23 x 32 23 x 23 x 32 23 x 23 x 32 23 x 23 x 47

Net Weight (Lbs) 114 124 144 167 114 125 144 167

Shipping Weight (Lbs) 125 135 155 180 125 135 155 180

R-22 Charge 25 29 42 68.5 23.5 27 42 63.5

* Normal Value Wet Coil @ .1" ESP.

ELECTRIC HEAT DATA

VEA/VHA09,12

Heater Watts 2500/2050 3400/2780 5000/4090 2500/2050 3400/2780 5000/4090

Heating Btu/h 8500/7000 11600/9500 17000/13900 8500/7000 11600/9500 17000/13900

Heating Current (Amps) 10.6/9.3 14.5/12.5 20.9/18.2 10.6/9.3 14.5/12.5 20.9/18.2

Minimum Circuit Ampacity 15 19.9 27.9 15 19.9 27.9

Branch Circuit Fuse (Amps) 15 20 30 15 20 30

Basic Heater Size 2.5 Kw 3.4 Kw 5.0 Kw 2.5 Kw 3.4 Kw 5.0 Kw

VEA/VHA18,24

Heater Watts 2500/2050 3400/2780 5000/4090 2500/2050 3400/2780 5000/4090 7500/6135 10000/8180

Heating Btu/h 8500/7000 11600/9500 17000/13900 8500/7000 11600/9500 17000/13900 25598/20939 34130/27918

Heating Current (Amps) 10.6/9.3 14.5/12.5 20.9/18.2 10.9/9.9 14.8/13.4 21.7/19.7 32.6/29.5 43.5/39.3

Minimum Circuit Ampacity 15 19.9 27.9 17.2/15.9 22.1/20.3 30.7/28.1 44.3/40.4 57.9/52.7

Branch Circuit Fuse (Amps) 15 20 30 25/25 25/25 35/30 45/45 60/60

Basic Heater Size 2.5 Kw 3.4 Kw 5.0 Kw 2.5 Kw 3.4 Kw 5.0 Kw 7.5 Kw 10.0 Kw

VE/VHA09 VE/VHA12

Voltage 230/208 230/208

VE/VHA18 VE/VHA24

Voltage 230/208 230/208

5

VERT-I-PAK

Model V(E,H)A09 V(E,H)A12 V(E,H)A18 V(E,H)A24
Voltage (V)
Refrigerant
Chassis Width
Chassis Depth
Chassis Height **
Shipping W x D x H
Supply Duct Collar ***
Drain Connection
Min. Circuit Amps
CFM Indoor
Max. Duct ESP

** Height includes 2" duct collar & isolators under unit. *** Factory collar accepts 10" fl ex duct.

®

E & G SUFFIX CHASSIS SPECIFICATIONS

230 / 208 230 / 208 230 / 208 230 / 208

R-22 R-22 R-22 R-22

23.125" 23.125" 23.125" 23.125"

23.125" 23.125" 23.125" 23.125"

32.25" 32.25" 32.25" 47.25"

26" x 28.5" x 35.0" 26." x 28.5" x 35" 26" x 28.5" x 35" 26" x 28.5" x 50"

10" 10" 10" 10"

3/4" FPT 3/4" FPT 3/4" FPT 3/4" FPT

.3 in. water .3 in. water .3 in. water .3 in. water

See Chassis Nameplate

Page 11

VEA/VHA9K-24K

COOLING DATA

Cooling Btu/h 9500/9300 11800/11500 18000/17800 24000 9500/9300 11800/11500 18000/17800 23500

Cooling Power (W) 880 1093 2070 2526 905 1124 2070 2474

EER 10.8 10.8 8.7 9.5 10.5 10.5 8.7 9.5

Sensible Heat Ratio 0.74 0.72 0.70 0.70 0.74 0.72 0.70 0.70

HEAT PUMP DATA

Heating Btu/h N/A N/A N/A N/A 8500/8300 10600/10400 15700/15500 22500
COP @ 47°F N/A N/A N/A N/A 3.0 3.2 3.0 3

Heating Power (W) N/A N/A N/A N/A 830 971 1705 2200

Heating Current (A) N/A N/A N/A N/A 4.4/4.9 5.5/6.1 9.2/10.2 11.4

ELECTRICAL DATA

Voltage (1 Phase, 60 Hz) 230/208 230/208 230/208 230/208 230/208 230/208 230/208 230/208

Volt Range 253-198 253-198 253-198 253-198 253-198 253-198 253-198 253-198

Cooling Current (A) 4.1/4.3 4.9/5.3 9.2/10.2 11.2/12.4 4.2/4.4 5.0/5.5 9.2/10.2 11.2/12.4

Amps L.R. 21 21 47 68 21 21 47 68

Amps F.L. 3.7 4.5 7.9 10.2 3.7 4.5 7.9 10.2

Indoor Motor (HP) 1/4 1/4 1/4 1/4 1/4 1/4 1/4 1/4

Indoor Motor (A) 1.2 1.2 1.4 2 1.2 1.2 1.4 2

Outdoor Motor (HP) N/A N/A N/A 1/4 N/A N/A N/A 1/4

Outdoor Motor (A) N/A N/A N/A 2 N/A N/A N/A 2

AIRFLOW DATA

Indoor CFM* 300 350 550 750 300 375 550 750

Vent CFM 60 60 60 80 60 60 60 80
Max. ESP .3" .3" .3" .3" .3" .3" .3" .3"

PHYSICAL DATA

Dimensions (W x D x H) 23x23x32 23x23x32 23x23x32 23x23x47 23x23x32 23x23x32 23x23x32 23x23x47

Net Weight (Lbs) 114 124 144 167 114 125 144 167

Shipping Weight (Lbs) 125 135 155 180 125 135 155 180

R-22 Charge 25 29 42 68.5 23.5 27 42 63.5

* Normal Value Wet Coil @ .1" ESP.

VEA09K VEA12K VEA18K VEA24K VHA09K VHA12K VHA18K VHA24K

ELECTRIC HEAT DATA

VEA/VHA09,12

Heater Watts 2500/2050 3400/2780 5000/4090 2500/2050 3400/2780 5000/4090

Heating Btu/h 8500/7000 11600/9500 17000/13900 8500/7000 11600/9500 17000/13900

Heating Current (Amps) 10.6/9.3 14.5/12.5 20.9/18.2 10.6/9.3 14.5/12.5 20.9/18.2

Minimum Circuit Ampacity 15 19.9 27.9 15 19.9 27.9

Branch Circuit Fuse (Amps) 15 20 30 15 20 30

Basic Heater Size 2.5 Kw 3.4 Kw 5.0 Kw 2.5 Kw 3.4 Kw 5.0 Kw

VEA/VHA18,24

Heater Watts 2500/2050 3400/2780 5000/4090 2500/2050 3400/2780 5000/4090 7500/6135 10000/8180

Heating Btu/h 8500/7000 11600/9500 17000/13900 8500/7000 11600/9500 17000/13900 25598/20939 34130/27918

Heating Current (Amps) 10.6/9.3 14.5/12.5 20.9/18.2 10.9/9.9 14.8/13.4 21.7/19.7 32.6/29.5 43.5/39.3

Minimum Circuit Ampacity 15 19.9 27.9 17.2/15.9 22.1/20.3 30.7/28.1 44.3/40.4 57.9/52.7

Branch Circuit Fuse (Amps) 15 20 30 25/25 25/25 35/30 45/45 60/60

Basic Heater Size 2.5 Kw 3.4 Kw 5.0 Kw 2.5 Kw 3.4 Kw 5.0 Kw 7.5 Kw 10.0 Kw

6

VE/VHA09 VE/VHA12

Voltage 230/208 230/208

VE/VHA18 VE/VHA24

Voltage 230/208 230/208

VERT-I-PAK® A - D SUFFIX CHASSIS SPECIFICATIONS

Model V(E,H)A09 V(E,H)A12 V(E,H)A18
Voltage (V) 230 / 208 230 / 208 230 / 208
Refrigerant R-22 R-22 R-22
Chassis Width 23.125" 23.125" 23.125"
Chassis Depth 23.125" 23.125" 23.125"
Chassis Height ** 32.25" 32.25" 32.25"
Shipping W x D x H 26" x 28" x 35" 26" x 28" x 35" 26" x 28" x 35"
Supply Duct Collar *** 10" 10" 10"
Drain Connection 1/2" MPT 1/2" MPT 1/2" MPT
Drain Hose **** 12" long 12" long 12" long
Thermostat Harness 36" long 36" long 36" long
Power Cord 60" long 60" long 60" long
Min. Circuit Amps See Chassis Nameplate
CFM Indoor Page 15
Fan Speeds 222
Max. Duct ESP .3 In. water .3 In. water .3 In. water

NOTES: ** Height includes 2" duct collar & isolators under unit. *** Factory collar accepts 10" fl ex duct.

MODELS V(E,H)A09K25 V(E,H)A09K34 V(E,H)A09K50 V(E,H)A12K25 V(E,H)A12K34 V(E,H)A12K50 V(E,H)A18K25 V(E,H)A18K34 V(E,H)A18K50

Cooling Cap. (Btu/h) 9500/9300 9500/9300 9500/9300 11500/11300 11500/11300 11500/11300 17200/17000 17200/17000 17200/17000

Cooling Power (W) 950 950 950 1200 1200 1200 1911 1911 1911

SEER 10.0 10.0 10.0 10.0 10.0 10.0 10.0 10.0 10.0

Water Removal (Pts/h) 2.1 2.1 2.1 2.8 2.8 2.8 4.0 4.0 4.0

Cooling SHR 0.77 0.77 0.77 0.76 0.76 0.76 0.75 0.75 0.75

Heater Size (KW) 2.5 3.4 5.0 2.5 3.4 5.0 2.5 3.4 5.0

Heating Cap.(Btu/h) 8500/7000 11600/9500 17000/13900 8500/7000 11600/9500 17000/13900 8500/7000 11600/9500 17000/13900

Heating Power (W) 2500/2050 3500/2780 5000/4090 2500/2050 3500/2780 5000/4520 2500/2050 3500/2780 5000/4520

Heating Current (A) 11.9/11.2 15.9/14.6 22.6/20.6 11.9/11.2 15.9/14.6 22.6/20.6 11.9/11.2 15.9/14.6 22.6/20.6

Heating Cap.(Btu/h) 8000/7800 8000/7800 8000/7800 11200/11000 11200/11000 11200/11000 15700/15500 15700/15500 15700/15500

Heating Power (W) 950 950 950 1200 1200 1200 1830 1830 1830

Heating Current (A) 4.4/4.9 4.4/4.9 4.4/4.9 5.2/6.0 5.2/6.0 5.2/6.0 9.0/10.0 9.0/10.0 9.0/10.0

0

COP @ 47

Voltage (V) 230/208 230/208 230/208 230/208 230/208 230/208 230/208 230/208 230/208

LRA - Comp. (A) 2 0 20 20 26.3 26.0 26.3 45 45 45

Cooling Current (A) 4.4/4.9 4.4/4.9 4.4/4.9 5.5/6.1 5.2/6.0 5.2/6.0 7.6 7.6 7.6

MIN. Ckt. Amps (A) 15 20 30 15 20 30 15 20 30

Power Connection POWER CORD POWER CORD POWER CORD WITH OPTION TO HARD WIRE

Refrigerant R-22 R-22 R-22 R-22 R-22 R-22 R-22 R-22 R-22

Unit Width (in.) 23.125 23.125 23.125 23.125 23.125 23.125 23.125 23.125 23.125

Unit Depth (in.) 23.125 23.125 23.125 23.125 23.125 23.125 23.125 23.125 23.125

Unit Height* (in.) 32.25 32.25 32.25 32.25 32.25 32.25 32.25 32.25 32.25

Shipping Weight (lbs.) 125 125 125 135 135 135 155 155 155

Indoor CFM ** 300 300 300 375 375 375 550 550 550

Fresh Air CFM** 60 60 60 60 60 60 60 60 60

Motor 230V, 1/4 HP 230V, 1/4 HP 230V, 1/4 HP 230V, 1/4 HP 230V, 1/4 HP 230V, 1/4 HP 230V, 1/4 HP 230V, 1/4 HP 230V, 1/4 HP

Motor Amps** 1.4 1.4 1.4 1.4 1.4 1.4 1.4 1.4 1.4

F 3.0 3.0 3.0 3.0 3.0 3.0 2.4 2.4 2.4

*Height includes 2" high duct collar and 5/8" isolators under unit.
**Normal Value Dry Coil on High Speed @ .3" ESP.

Due to continuing research in new energy-saving technology,
specifi cations are subject to change without notice.

Capacity rated at standard conditions:
COOLING–
950F DB/750F WB outdoor, 800F DB/670F WB indoor
HEATING– (reverse cycle)

0

F DB/430F WB outdoor, 700F DB/600F WB indoor

47

7

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 diffi cult 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:

1. "Heat always fl ows 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"

3. "Flow is always from a higher pressure area to a lower
pressure area."

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 fi nned
surface facilitates the transfer of heat from the refrigerant to
the relatively cooler outdoor air.

When a suffi cient 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 fl ow across the condenser coil.

The Vert-I-Pak 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 refrigerant leaves the condenser coil through the liquid
li ne as a WAR M high press ure liquid. It nex t wil l pass throu gh
the refrigerant drier (if so equipped). It is the function of the
drier to trap any moisture present in the system, 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.

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.

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 fi nned 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.

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 fl ow across
the evaporator 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 low pressure (suction) created by the compressor causes
the 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

8

Electrical Supply

WARNING: Electrical shock hazard.

Turn OFF electric power at fuse box or service panel
before making any electrical connections and ensure a
proper ground connection is made before connecting line
voltage.

All electrical connections and wiring MUST be installed by
a qualifi ed electrician and conform to the National Electrical
Code and all local codes which have jurisdiction.

Failure to do so can result in property damage, personal
injury and/or death.

Supply Circuit

The system cannot be expected to operate correctly unless
the system is properly connected (wired) to an adequately
sized single branch circuit. Check the installation manual
and/or technical data for your particular unit and/or strip
heaters to determine if the circuit is adequately sized.

Electrical Rating Tables

NOTE: Use copper conductors ONLY
Wire sizes are per NEC. Check local codes for

overseas applications

Supply Voltage

To insure proper operation, supply voltage to the system
should be within fi ve (5) percent (plus or minus) of listed
rating plate voltage.

Control (Low) Voltage

To insure proper system operation, the transformer
secondary output must be maintained at a nominal 24 volts.
The control (low) voltage transformer is equipped with
multiple primary voltage taps. Connecting the primary,
(supply) wire to the tap (i.e., 208 and 240 volts) that most
closely matches the MEASURED supply voltage will insure
proper transformer secondary output is maintained.

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 specifi ed range
can be expected to cause operating problems. Their cause
MUST be investigated and corrected.

Electrical Ground

GROUNDING OF THE ELECTRICAL SUPPLY TO ALL
UNITS IS REQUIRED for safety reasons.

A through D Suffi x

250 V Receptacles and Fuse Types

Units Only

AMPS 15 20 * 30

RECEPTACLE

MANUFACTURER PART NUMBERS

Hubbell 5661 5461 9330
P & S 5661 5871 5930
GE GE4069-1 GE4182-1 GE4139-3
Arrow-Hart 5661 5861 5700

TIME-DELAY TYPE
FUSE 15 20 30

(or HACR circuit breaker)

HACR — Heating, Air Conditioning, Refrigeration
* May be used for 15 Amp applications if fused for 15 Amp

Recommended branch circuit wire sizes*

Nameplate maximum circuit

breaker size

15A 14
20A 12
30A 10

AWG — American Wire Gauge
* Single circuit from main box
** Based on copper wire, single insulated conductor at 60°C

AWG Wire size**

Electrical Requirements

NOTE: All fi eld wiring must comply with

NEC and local codes. It is the
responsibility of the installer to
insure that the electrical codes are
met.

Wire Size Use ONLY w iring size r ecomme nded

for single outlet branch circuit.

Fuse/Circuit Use ONLY type and size fuse or

HACR circuit breaker

Breaker Indicated on unit's rating plate (See

sample on page 6).

Proper current protection to the unit

is the responsibility of the owner.

Grounding Unit MUST be grounded from branch

circuit to unit, or through separate
ground wire provided on permanently
connected units. Be sure that branch
circuit or general purpose outlet is
grounded.

Wire Sizing Use recommended wire size given in

the tables below and install a single
branch circuit. All wiring must comply
with local and national codes. NOTE:
Use copper conductors only.

9

Room Thermostats

Room thermostats are available from several different
manufacturers in a wide variety of styles. They range from
the very simple Bimetallic type to the complex electronic
set-back type. In all cases, no matter how simple or
complex, they are simply a switch (or series of switches)
designed to turn equipment (or components) "ON" or "OFF"
at the desired conditions.

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.

Location

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
fl oor in an area of average temperature, with good air
circulation. Close proximity to the return air grille is the
best choice.

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.

Measuring Current Draw

Thermostat Location

In order to accomplish this, the heat output from the
anticipator must be the same regardless of the current
fl owing through it. Consequently, some thermostats have
an adjustment to compensate for varying current draw in
the thermostat circuits.

The proper setting of heat anticipators then is important
to insure proper temperature control and customer
satisfaction. A Heat anticipator that is set too low will
cause the heat source to cycle prematurely possibly never
reaching set point. A heat anticipator that is set too high
will cause the heat source to cycle too late over shooting
the set point.

Heat Anticipators

Heat anticipators are small resistance heaters (wired
in series with the "W" circuit) and built into most
electromechanical thermostats. Their purpose is to prevent
wide swings in room temperature during system operation
in the HEATING mode. Since they are wired in series,
the "W" circuit will open if one burns out preventing heat
operation.

The heat anticipator provides a small amount of heat to
the thermostat causing it to cycle (turn off) the heat source
just prior to reaching the set point of the thermostat. This
prevents exceeding the set point.

10

The best method to obtain the required setting for the
heat anticipator, is to measure the actual current draw in
the control circuit ("W") using a low range (0-2.0 Amps)
Ammeter. After measuring the current draw, simply set
the heat anticipator to match that value.

If a low range ammeter is not available, a "Clamp-on" type
ammeter may be used as follows:

1. Wrap EXACTLY ten (10) turns of wire around the jaws
of a clamp-on type ammeter.

2. Connect one end of the wire to the "W" terminal of
the thermostat sub-base, and the other to the "R"
terminal.

3. Turn power on, and wait approximately 1 minute, then
read meter.

4. Divide meter reading by 10 to obtain correct anticipator
setting.

Electronic thermostats do not use a resistance type
anticipator. These thermostats use a microprocessor
(computer) that determines a cycle rate based on a
program loaded into it at the factory.

Typical Electrical & Thermostat Wiring Diagrams

VEA/VHA 24K

FOR 208 VOLT MODELS ONLY

MOVE THE WHITE WIRE AS

RT2

THERMOSTAT

(FRONT)

SHOWN BELOW

BLACK

COM.

208V 240V

WHITE

THERMOSTAT CONNECTIONS

(EAR)

UP

G
R

R

W

Y

WHITE

BROWN

TERM BOARD

BROWN

YELLOW

YWRGBC

TRANSFORMER

24V

BLACK

B

C

RED

RED

c

CAPACITOR

HERM

WHITE

QUICK DISCONNECT

L1

BLACK

BLUE

COM.

TRANSFORMER

24V

208V

L2

WHITE

240V

GREEN

SEE NOTE #6

TO MOTOR

MOUNT

WHITE

RED

BLACK

RED

BLACK

BLACK

GREEN

CONDENSER

MOTOR

RED

BLACK
BLUE
RED

"F"

S

COMP WIRE HARNESS

R

C

"F"

"F"

COMPRESSOR

FAN

BLACK

BLUE

GREEN

RED

YELLOW

WHITE

123

COMPR RELAY

4

LOW AMBIENT

RED

BLACK

WHITE

BROWN

RED

COIL, SOLENOID

RED

BLACK

WHITE

CONTROL

WIRE NUT (RED)

WHITE

RED

PRESSURE

SWITCH

YELLOW

CAPACITOR

YELLOW

HEATER

2.5 KW & 3.4 KW
5 KW

WHITE

FAN

RELAY

2

2 4

1 3

BLACK

BLACK

c

FAN

BROWN

HERM

RED

REV VALVE

4

31

RELAY

WHITE

BLUE

HEAT

RELAY

(2.5KW/3.4KW

2 4

1 3 123

BLACK

BLACK

RED

C

H

L

GREEN

BLOWER

MOTOR

5 KW)

T-STAT
DEFROST

INSULATOR

2-REQ'D

WIRE NUT (RED)

SEE NOTE #4

BLACK

TO MOTOR
MOUNT

7.5 KW & 10 KW

RED

RELAY

2 4

1 3

HEATER

HEAT

(2.5KW/3.4KW

5 KW)

BLACK

BLACK

RED

RED

HEAT
RELAY
(7.5KW/10KW) (7.5KW/10KW)

2

4

1

BLACK

BLACK

HEAT
RELAY

4

3

NOTE: THE DIAGRAM ABOVE ILLUSTRATES THE TYPICAL THERMOSTAT WIRING AND 208

VOLT TRANSFORMER WIRING. SEE THE UNIT CONTROL PANEL FOR THE ACTUAL
UNIT WIRING DIAGRAM AND SCHEMATIC.

11

Typical Electrical & Thermostat Wiring Diagrams

G & H Suffi x

COM. 208V 240V

RT1

THERMOSTAT

(FRONT)

12

NOTE: THE DIAGRAM ABOVE ILLUSTRATES THE TYPICAL

THERMOSTAT WIRING AND 208 VOLT TRANSFORMER
WIRING. SEE THE UNIT CONTROL PANEL FOR THE
ACTUAL UNIT WIRING DIAGRAM AND SCHEMATIC.

Typical Electrical & Thermostat Wiring Diagrams

A – E Suffi x

FOR 208 VOLT MODELS ONLY:

MOVE THE WHITE WIRE AS

SHOWN BELOW.

13

Indoor Blower - Airfl ow

The current Vert-I -Pak 9, 12, & 18 use a dual shaft, permanent
split capacitor, single speed motor to drive indoor blower and
outdoor fan. Earlier model VERT-I-Pak units used 2-speed
motors. The Vert-I-Pak 24 uses an individual, single shaft,
permanent split capacitor, single speed motor for the indoor
blower, and a separate motor drives the outdoor fan.

Different size (HP) motors and/or different diameter blower
wheels are used in different models to obtain the required
airfl ow.

Indoor Blower - Airfl ow

The current Vert-I -Pak 9, 12, & 18 use a dual shaft, permanent
split capacitor, single speed motor to drive indoor blower and
outdoor fan. Earlier model VERT-I-Pak units used 2-speed
motors. The Vert-I-Pak 24 uses an individual, single shaft,
permanent split capacitor, single speed motor for the indoor
blower, and a separate motor drives the outdoor fan.

Different size (HP) motors and/or different diameter blower
wheels are used in different models to obtain the required
airfl ow.

Condenser Fan Motors

The current Vert-I-Pak 9, 12, & 18 units use a dual shaft,
permanent split capacitor, single speed motor to drive indoor
and outdoor fan. Earlier models used a 2-speed motor. The
Vert-I-Pak 24 uses and individual, single shaft, permanent
split capacitor, single speed motor for the outdoor fan, with a
separate motor driving the indoor blower.

Blower Wheel Inspection

Visually inspect the blower wheel for the accumulations
of dirt or lint since they can cause reduced airfl ow. Clean
the blower wheel of these accumulations. If accumulation
cannot be removed, it will be necessary to remove the
blower assembly from the unit for proper wheel cleaning.

Cooling

A nominal 400 (350-450 allowable) CFM per ton of airfl ow
is required to insure proper system operation, capacity,
and effi ciency. Factory-set blower speeds should provide
the proper airfl ow for the size (Cooling capacity) of the unit
when connected to a properly sized duct system.

Cooling (VEA/VHA 24)

When the thermostat is set for cooling mode (SYSTEM
switch set to COOL and FAN switch to AUTO) a rise in room
temperature will make It also causes a 24-volt signal on the
“Y” thermostat conductor through the high pressure and low
ambient switches energizing the compressor relay, turning
on the compressor and outdoor fan motor. A 24-volt signal
on the “G” thermostat terminal to the Fan Relay, turning on
the indoor blower motor.

Heating (Electric)

When using electric heaters, select the blower speed that
provides adequate airfl ow across the elements to prevent
overheating and cycling on limit and/or premature failure.
CHECK THE EXTERNAL STATIC PRESSURE, and then
consult the AIR FLOW DATA to determine the ACTUAL air
fl ow delivered for the factory selected fan speed. This will
be especially important on change-outs using an existing
duct system that may not have been properly sized to
begin with.

Heating (VEA/VHA 24)

When the thermostat is set for heating mode (System switch
set to HEAT and FAN switch to AUTO) it will make a 24­volt signal on the “B” thermostat terminal to energize the
Reversing Valve Relay. A drop in room temperature, will
make a 24-volt signal on the “W” thermostat terminal to the
Defrost Thermostat, and “G” thermostat terminal to the Fan
Relay. The Defrost Thermostat will determine whether the
unit should run in Heat Pump, or Electric Heat, based on the
outdoor temperature. (See Defrost Thermostat page 24)

External Static Pressure

External Static Pressure can best be defi ned 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 airfl ow (Friction) in the air distribution
system EXTERNAL to the VERT-I-PAK cabinet.

Resistance applied externally to the VERT-I-PAK (i.e. duct
work, coils, fi lters, etc.) on either the supply or return side
of the system causes an INCREASE in External Static
Pressure accompanied by a REDUCTION in airfl ow.

External Static Pressure is affected by two (2) factors.

1. Resistance to Airfl ow as already explained.

2. Blower Speed. Changing to a higher or lower blower
speed will raise or lower the External Static Pressure
accordingly.

These affects must be understood and taken into consideration
when checking External Static Pressure/Airfl ow to insure that
the system is operating within design conditions.

Operating a system with insuffi cient or excessive airfl ow
can cause a variety of different operating problems.
Among these are reduced capacity, freezing evaporator
coils, premature compressor and/or heating component
failures. etc.

System air fl o w s hould always be veri fi e d upon co mp letion
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 airfl ow.

14

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 specifi c
VERT-I-PAK.

1. Set up to measure external static pressure at the
supply and return air.

the case of the VERT-I-PAK, the condensate will cause
a reduction in measured External Static Pressure for the
given airfl ow.

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, fi lters, grilles.

2. Drill holes in the supply duct for pressure taps, pilot
tubes or other accurate pressure sensing devices.

3. Connect these taps to a level inclined manometer
or Magnehelic gauges.

4. Ensure the coil and fi lter are clean, and that all the
registers are open.

5. Determine the external static pressure with the
blower operating.

6. Refer to the Air Flow Data for your VERT-I-PAK
system to fi nd the actual airfl ow for factory-selected
fan speeds.

7. If the actual airfl ow is either too high or too low, the
blower speed will need to be changed.

8. Select a speed, which most closely provides the
required airfl ow for the system.

9. Recheck the external static pressure with the
new speed. External static pressure (and actual
airfl ow) will have changed to a higher or lower value
depending upon speed selected. Recheck the actual
airfl ow (at this "new" static pressure) to confi rm
speed selection.

10. Repeat steps 8 and 9 (if necessary) until proper
airfl ow has been obtained.

Checking Approximate Airfl ow

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 fl ow call be calculated by measuring the
temperature rise, then using tile following criteria.

KILOWATTS x 3413

Temp Rise x 1.08

= CFM

Electric Heat Strips

The approximate CFM actually being delivered can be
calculated by using the following formula:

DO NOT simply use the Kilowatt Rating of the heater (i.e.

2.5, 3.4, 5 .0 ) as this wil l r esult in a les s-than-c orrec t airfl ow
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.

EXAMPLE: Measured voltage to unit (heaters) is 230 volts.
Measured Current Draw of strip heaters is 11.0 amps.

230 x 11.0 = 2530
2530/1000 = 2.53 Kilowatts

2.53 x 3413 = 8635

EXAMPLE: Airfl ow requirements are calculated as follows:
(Having a wet coil creates additional resistance to airfl ow.
This addit ional resistance must be taken into consideration
to obtain accurate airfl ow information.

1 ½ TON SYSTEM ( 18,000 Btu)

Operating on high speed @ 230 volts with dry coil

measured external static pressure .20

Air Flow = 500 CFM

In the same SYSTEM used in the previous example but
having a WET coil you must use a correction factor of
.94 (i.e. 500 x .94=470 CFM) to allow for the resistance
(internal) of the condensate on the coil.

It is important to use the proper procedure to check external
Static Pressure and determine actual airfl ow. Since in

Supply Air 95°F
Return Air 75°F
Temper ature Rise 20

20 x 1.08 = 21.6

8635

= 400 CFM

21.6

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.

°

15

Airfl ow Charts A – D Suffi x

Chart A CFM @ 230 Volts - DRY COIL

Model

Fan Speed

ESP (in water)

—

V(E,H)A09/A12 V(E,H)A18

>

—

High

>

CFM

0.00 N/A 427 N/A 517

0.10 411 387 510 480

0.20 373 347 500 470

0.30 327 310 490 460

Low

CFM

High

CFM

Low

CFM

Ductwork Preparation

Pull the fl ex duct tight. Extra fl ex duct slack can greatly
increase static pressure

Explanation of charts

Chart A is the nominal dry coil VERT-I-PAK CFMs. Chart
B is the correction factors beyond nominal conditions.

Chart A – CFM

Model 18000 12000 / 9000

.00 520 420

.10 510 410

.20 500 370

.30 490 330

Chart B – Correction Multipliers

Correction Multipliers for:

230V 1.00

208V 0.97

Heating 1.00

Cooling 0.95

Chart B Correction Factors

To Correct for:

230 Volts 1.00

208 Volts 0.97

Dry Coil 1.00

Wet Coil 0.94

Chart C – VE/VHA CFM

.1" ESP 750 815
.2" ESP 725 780
.3" ESP 700 745
.4" ESP 675 700

All value s listed are inches W.C. with a wet
indoor coil with fi lt er inst alled.

Correction

Factor

VEA/VHA24K

Low High

Refrigerant Charging

Note: Because the earlier model Vert-I- Paks are sealed
systems, service process tubes will have to be installed.
First install a line tap and remove refrigerant from system.

The H suffi x model Vert-I-Paks have factory installed ser-

vice values. Make necessary sealed system repairs and
vacuum system. Weigh in charge according to the unit data
plate. Crimp process tube line and solder end shut. Do
not leave a service valve in the sealed system.

Proper refrigerant charge is essential to proper unit
operation. Operating a unit with an improper refrigerant
charge will result in reduced performance (capacity) and/or
effi ciency. Accordingly, the use of proper charging methods
during servicing will insure that the unit is functioning as
designed and that its compressor will not be damaged.

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 fl ow across
evaporator, etc.) are misdiagnosed as refrigerant charge

16

problems. The refrigerant circuit diagnosis chart will assist
you in properly diagnosing these systems.

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 specifi c type of failure will be infl uenced by the
amount of liquid being returned, and the length of time the
slugging continues.

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 suffi cient 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.

Method Of Charging

The acceptable method for charging the Vert-I-Pak 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.

2. Recover Refrigerant in accordance with EPA
regulations.

3. Install a process tube to sealed system.

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:

1. Install a piercing valve to remove refrigerant from the
sealed system. (Piercing valve must be removed from
the system before recharging.)

4. Make necessary repairs to system.

5. Evacuate system to 300 microns or less.

6. Weigh in refrigerant with the property quantity of
R-22 refrigerant.

7. Start unit, and verify performance.

8. Crimp the process tube and solder the end shut.

NOTE: In order to access the sealed system it will be necessary to install Schrader type
fi ttings to the process tubes on the discharge and suction of the compressor. Proper
recovery refrigerant procedures need to be adhered to as outlined in EPA Regulations.
THIS SHOULD ONLY BE ATTEMPTED BY QUALIFIED SERVICE PERSONNEL.

Undercharged Refrigerant Systems

An undercharged system will result in poor performance
(low pressures, etc.) in both the heating and cooling
cycle.

Whenever you service a unit with an under charge of
refrigerant, always suspect a leak. The leak must be
repaired before charging the unit.

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).

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 insuffi cient air over
the evaporator.

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. A check of the
amper age drawn by the compressor motor should show a
lower reading. (Check the Unit Specifi cation.) After the unit
has run 10 to 15 minutes, check the gauge pressures.

Gauges connected to system with an under charge will
have low head pressures and substantially low suction
pressures.

17

Overcharged Refrigerant Systems

Compressor amps will be near normal or higher.
Noncondensables can also cause these symptoms. To
confi rm, remove some of the charge, if conditions improve,
system may be overcharged. If conditions don’t improve,
Noncondensables are indicated.

Whenever an overcharged system is indi cated, always
make sure that the problem is not caused by air fl ow
problems. Improper air fl ow over the evaporator coil may
indicate some of the same symptoms as an overcharged
system.

An over charge can cause the compressor to fail, since it
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

Restricted Refrigerant Systems

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.

of the evapora tor will not be encountered because the
refriger ant will boil later if at all. Gauges connected to
system will usually have higher head pressure (depending
upon amount of overcharge). Suction pressure should be
slightly higher.

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 specifi cation. 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.

The following conditions are based primar ily on a system
in the cooling mode.

Troubleshooting a restricted refrigerant system can
be diffi cult. The following proce dures are the more
common problems and solutions to these problems.
There are two types of refrigerant restrictions: Partial
restrictions and complete restrictions.

A partial restriction allows some of the refrigerant to
circulate through the system.

With a complete restriction there is no circulation of
refrigerant in the system.

18

Restricted refrigerant systems display the same symptoms as
a "low-charge condition." When the unit is shut off, the gauges
may equal ize very slowly. Gauges connected to a completely
re stricted system will run in a deep vacuum. When the unit
is shut off, the gauges will not equalize at all.

Metering Device - Capillary Tube Systems

All units are equipped with capillary tube metering devices.

Checking for restricted capillary tubes.

1. Connect pressure gauges to unit.

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.

Reversing Valve Description/Operation

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
Vert-I-Pak 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
of the system. The pilot section of the valve opens and
closes ports for the small capillary tubes to the main valve
to cause it to shift.

NOTE: System operating pressures must be near
normal before valve can shift.

WARNING

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.

4. If the operating pressures are lower than normal
in both the heating and cooling mode, the cooling
capillary is restricted.

Electrical Circuit and Coil

(Reversing valve coil is energized in the heating cycle only).

1. Set controls for heating; valve should shift.

2. Check for line voltage at the heat relay, terminal #2

and L2 at the quick disconnect. If line voltage is not
present check the power supply.

Testing Coil

1. Turn off high voltage electrical power to unit.

2. Unplug line voltage lead from reversing valve coil.

DANGER OF BODILY INJURY OR DEATH

FROM ELECTRICAL SHOCK

The reversing valve solenoid is connected to
high voltage. Turn off electrical power before
disconnecting or connecting high voltage wiring
or servicing valve.

3. Check for electrical continuity through the coil. If you

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.

5. If coil tests okay, reconnect the electrical leads .

6. Make sure coil has been assembled cor rectly.

19

Checking Reversing Valve

NOTE: You must have normal operating pressures before

the reversing valve can shift.

Check for proper refrigerant charge. Sluggish or sticky
reversing valves can sometimes be remedied by reversing
the valve several time with the airfl ow restri cted to inc re ase
system pressure.

To raise head pressure during the cooling season the airfl ow
through the outdoor coil can be restricted . During heating
the indoor air can be restricted by blocking the return air.

Dented or damaged valve body or capillary tubes can
prevent the main slide in the valve body from shifting.

If you determine this is the problem, replace the 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.

CAUTION

Never energize the coil when it is removed

from the valve, as a coil burnout will result.

Touch Test in Heating/Cooling Cycle

The only defi nite 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.

NOTE: A condition other than those illustrated above, and
on page 19, indicate that the reversing valve is not shifting
properly. Both tubes shown as hot or cool must be the same
corresponding tempera ture.

Procedure For Changing Reversing Valve

1. Install Process Tubes. Recover refrigerant from sealed
system. PROPER HANDLING OF RECOVERED
REFRIGERA NT 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 fi ttings on new valve.

5. Remove solenoid coil from new valve.

6. Protect new valve body from heat while brazing with
plastic heat sink (Thermo Trap) or wrap valve body with
wet rag.

Reversing Valve in Heating Mode

Reversing Valve in Cooling Mode

7. Fit all lines into new valve and braze lines into new
valve.

8. Pressurize sealed system with a combina tion of R-22
and nitrogen and check for leaks, using a suitable leak
detector. Recover refrigerant per EPA guidelines.

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.

20

WARNING

DANGER OF BODILY INJURY OR DEATH

FROM ELECTRICAL SHOCK

When working on high voltage equipment - turn the
electrical power off before attaching test leads.

Use test leads with alligator type clips - clip to terminals,
turn power on, take reading - turn power off before
removing leads.

Compressor Checks

Locked Rotor Voltage (L.R.V.) Test

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 com­pressor. Restore power to unit.

CAUTION

Make sure that the ends of the lead do not touch the
compressor shell since this will cause a short circuit.

Determine L.R.V.

Start the compressor with the voltmeter 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 specifi ed on the rating plate. If less than
mini mum, check for cause of inadequate power supply; i.e.,
incorrect wire size, loose electrical connections, etc.

Amperage (L.R.A.) Test

The running amperage of the compressor is the most
important of these readings. A running amperage higher
than that indicated in the performance data indicates that
a problem exists mechanically or electrically.

Single Phase Running and L.R.A. Test

NOTE: Consult the specifi cation and perform ance section

for running amperage. The L.R.A. can also be found on
the rating plate.

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 am perage on the
meter. If the compressor does not start, the reading will
indicate the locked rotor amperage (L.R.A.).

External Overload

Some compressors are equipped with an exter nal overload
which senses both motor amperage and winding temperature.
High motor tempera ture or amperage heats the overload
causing it to open, breaking the common circuit within the
compressor.

Heat generated within the compressor shell, usually due
to recycling of the motor, is slow to dissipate. It may take
anywhere from a few minutes to several hours for the
overload to reset.

Checking the External Overload

With power off, remove the leads from com pressor
terminals. If the compressor is hot, allow the overload
to cool before starting check. Using an ohmmeter, test
continuity across the terminals of the external overload. If
you do not have continuity; this indicates that the over load
is open and must be replaced.

Internal Overload

Some compressors are equipped with an 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. Heat generated within the compressor shell,
usually due to recycling of the motor, is slow to dissipate. It
may take anywhere from a few minutes to several hours for
the overload to reset.

Checking the Internal Overload

A reading of infi nity (∞) between any two terminals MAY
indicate an open winding. If, however, a reading of infi nity
(∞) is obtained between C & R and C & S, accompanied
by a resistance reading between S & R, an open internal
overload is indicated. Should you obtain this indication,
allow the compressor to cool (May take up to 24 hours) then
recheck before condemning the compressor. If an open
internal overload is indicated, the source of its opening must
be determined and corrected. Failure to do so will cause
repeat problems with an open overload and/or premature
compr essor f ailure. Some p ossibl e cause s of an open i nte rn al
overload include insuffi cient refrigerant charge, restriction in
the refrigerant circuit, and excessive current draw.

21

Single Phase Resistance Test

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").

Add values "C" to "S" and "C" to "R" together and check resis­tance from start to run terminals ("S" to "R"). Resistance "S"
to "R" should equal the total of "C" to "S" and "C" to "R."

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.

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.

Complete evaluation of the system must be made whenever
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.

Many compressor failures are caused by the following condi­tions.

1. Improper air fl ow over the evaporator.

2. Overcharged refrigerant system causing liquid to be re­turned to the compressor.

Recommended Procedure for
Compressor Replacement

NOTE: Be sure power source is off, then disconnect all
wiring from the compressor.

1. Be certain to perform all necessary electrical and refrigera­tion tests to be sure the compressor is actually defective
before replacing .

2. Recover all refrigerant from the system though the process
tubes. PROPER HANDLING OF RECOVERED RE-

FRIGERANT 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.

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.

4. Carefully pour a small amount of oil from the suction stub

of the defective compressor into a clean container.

5. Using an acid test kit (one shot or conven tional kit), test

the oil for acid content according to the instructions with
the kit.

6. If any evidence of a burnout is found, no matter how

slight, the system will need to be cleaned up following
proper procedures.

3. Restricted refrigerant system.

4. Lack of lubrication.

5. Liquid refrigerant returning to compressor causing oil to
be washed out of bearings.

6. Noncondensables such as air and moisture in the system.
Moisture is extremely de structive to a refrigerant system.

7. Install the replacement compressor.

8. Pressur ize with a combinati on of R-22 and n it rogen a nd
leak test all connections with an electronic or Halide
leak detector. Recover refrigerant and repair any leaks
found.

Repeat Step 8 to insure no more leaks are present.

9. Evacuate the system with a good vacuum pump capable
of a fi nal vacuum of 300 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. Compressor
manufacturers will void warranties on units received not
properly sealed. Do not distort the manufacturers tube
connections.

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, electronic scales or similar
device is necessary.

22

WARNING

HAZARD OF SHOCK AND ELECTROCUTION. A
CAPACITOR CAN HOLD A CHARGE FOR LONG

PERIODS OF TIME. A SERVICE TECHNICIAN WHO

TOUCHES THESE TERMINALS CAN BE INJURED.

NEVER DISCHARGE THE CAPACITOR BY SHORTING

ACROSS THE TERMINALS WITH A SCREWDRIVER.

Capacitors

Many motor capacitors are internally fused. Shorting the
terminals will blow the fuse, ruin ing 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.

Capacitor Check With Capacitor Analyzer

The capacitor analyzer will show whether the capacitor is
"open" or "shorted." It will tell whether the capacitor is within
its microfarads 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

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.

From the supply line on a typical 230 volt circuit, a 115 volt
potential exists from the "R" terminal to ground through a
possible short in the capacitor. However, from the "S" or
start 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 identifi ed terminal is con­nected to the “S" or start terminal. The identifi ed 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
tem perature.

23

Emergency Heat Switch (Defrost Thermostat) Continuity Check

Electric Heat Switch Operation

(Heat Pumps Only)

The electric heat switch is a dual function control and is
shown on the wiring diagram as a defrost thermostat.
It may be adjusted using a screwdriver. As the control
shaft is rotated counter clockwise a detent will be
encountered. Turning the control past the detent will lock
out the compressor and acts as an emergency heat switch.
Turning the control shaft clockwise will lower the change
over point for compressor operation. The control it self is
a double throw, single pole switch operated by a bellows
and a gas fi lled capillary tube. The capillary tube senses
a combination of outdoor coil temperature and outdoor air
temperature. As the combined temperatures reach a point
that the outdoor coil is iced, where heat pump operation
is no longer effi cient, the control shuts off the compressor
and turns on the electric heat. At its lowest setting the cut
off point is approximately 25 degrees, the highest setting
is 52 degrees, with a 10 degree differential. It is possible,
under certain conditions, for the unit to cycle between
compressor and electric heat operation.

Electric Heat Switch Check Out

The switch may be checked out with an ohmmeter.
Remove and label the three wires from the switch.
Terminal 2 is common and the contacts make to Terminal
3 on temperature rise and to Terminal 1 on temperature
fall. With the control set in the emergency heat position
continuity should be read between Terminal 2 and Terminal
1 regardless of coil temperature. As the control shaft is
rotated clockwise, through the adjustment range, continuity
will be read between Terminal 2 and Terminal 3, providing
the temperature of the capillary tube is above 25º (± 5%). If
the temperature at the capillary tube is above approximately
52 degrees it may be necessary to place the end of the
capillary tube in ice water to determine if the control is
sensing temperature changes. Should the control lose the
gas charge in the capillary tube it will fail to the electric heat
position and the compressor will not operate.

24

SWITCH POSITION TEMPERATURE AT CAPILLARY CONTINUITY READ

EMERGENCY HEAT N/A 1 and 2 = Electric Heat

ANYWHERE IN

ADJUSTMENT RANGE

ANYWHERE IN

ADJUSTMENT RANGE

ABOVE SET POINT 2 and 3 = Compressor

BELOW SET POINT 1 and 2 = Electric Heat

Wiring Diagram Index

MODEL DIAGRAM PAGE

VEA09K00 RTA ................... 80004910 ...................28

VEA09K00RTB ................. 80004910 ...................28

VEA09K00RTE ................. 80004910 ...................28

VEA09 K00RTG ................. 8000492 2 ...................34

VEA09 K00RTH ................. 80004922 ...................34

VEA09K25 RTA ................ 80004911 ....................30

VEA09K25RTB ................. 80004911 ....................30

VEA09K25RTE ................. 80004911 ....................30

VEA09 K25RTG ................. 8000 4923 ................... 35

VEA09 K25RTH ................. 8000 4923 ...................35

VEA09K34RTA .................. 80004911 ....................30

VEA09K34RTB ................. 80004911 ....................30

VEA09K34RTE ................. 80004911 ....................30

VEA09 K34RTG ................. 800 04923 ...................35

MODEL DIAGRAM PAGE

VEA12K34RTG .................. 80004920 ...................32

VEA12K34RTH .................. 800 04 920 ................... 32

VEA12K50RTA .................. 80004911 ....................30

VEA12K50RTB .................. 800 04911 ....................30

VEA12K50RTE .................. 800 04911 ....................30

VEA12K50RTG .................. 80004920 ...................32

VEA12K50RTH .................. 800 0 492 0 ...................32

VEA18K00RTA .................. 80 004910 ................... 28

VEA18K00RT B .................. 8 00 04910 ................... 28

VEA18K00RTC .................. 800 0 4910 ................... 28

VEA18K00RTD .................. 80004910 ...................28

VEA18K00RT E .................. 8 00 04910 ................... 28

VEA18K00RTG ................. 80004919 ...................31

VEA18K00RTH .................. 80004919 ...................31

VEA09K34RTH ................. 80004923 ...................35

VEA09K50RTA .................. 80004911 ....................30

VEA09K50RTB ................. 80004911 ....................30

VEA09K50RTE ................. 80004911 ....................30

VEA09 K50RTG ................. 80 004923 ................... 35

VEA09 K50RTH ................. 800 04923 ...................35

VEA12K00RTA .................. 80004910 ................... 28

VEA12K00RTB .................. 800 04910 ................... 28

VEA12K00RTE .................. 800 04910 ................... 28

VEA12K00RTG .................. 80004919 ...................31

VEA12K00RTH .................. 800 0 4 919 ................... 31

VEA12K25RTA .................. 80 004911 ....................30

VEA12K25RT B .................. 8 000 4911 ....................30

VEA12K25RT E .................. 8 000 4911 ....................30

VEA12K25RTG ................. 80004920 ...................32

VEA12K25RTH .................. 80004920 ...................32

VEA18K 25RTA .................. 80 004911 ....................30

VEA18K 25RTB .................. 800 04911 ....................30

VEA18K25RTC .................. 80004911 ....................30

VEA18K25RTD ................. 80004911 ....................30

VEA18K 25RTE .................. 800 04911 ....................30

VEA18K25RTG ................. 80004920 ...................32

VEA18K25RTH ................. 80004920 ...................32

VEA18K34RTA .................. 80004911 ....................30

VEA18K34RTB .................. 80 004911 ....................30

VEA18K34RTC .................. 800 04911 ....................30

VEA18K34RTD .................. 80004911 ....................30

VEA18K34RTE .................. 80 004911 ....................30

VEA18K34RTG ................. 80004920 ...................32

VEA18K34RTH .................. 80004920 ...................32

VEA18K50RTA .................. 80 004911 ....................30

VEA18K50RT B .................. 8 000 4911 ....................30

VEA12K34RTA .................. 80004911 ....................30

VEA12K34RTB .................. 800 04911 ....................30

VEA12K34RTE .................. 800 04911 ....................30

VEA18K50RTC .................. 800 04 911 ....................30

VEA18K50RTD .................. 80004911 ....................30

VEA18K50RT E .................. 80 00 4911 ....................30

25

MODEL DIAGRAM PAGE MODEL DIAGRAM PAGE

VEA18K50RTG ................. 80004920 ...................32

VEA18K50RTH .................. 80004920 ...................32

VEA24K00RTH ................. 80110500 ....................37

VEA24K10RTH ................. 80108800 ...................38

VEA 24K25RTH ................. 8010880 0 ...................38

VEA24K34RTH ................. 80108800 ...................38

VEA24K50RTH ................. 80108800 ...................38

VEA24K75RTH ................. 80108800 ...................38

VHA09K25RTA ................. 800004912 .................29

VHA09K25RTB ................. 8 00004912 .................29

VHA09K25RTE ................. 800004912 .................29

VHA09 K25RTG ................. 800004924 .................36

VHA09 K25RTH ................. 800004924 .................36

VHA09K34RTA ................. 800004912 .................29

VHA09K34RTB ................. 800004912 .................29

VHA09K34RTE ................. 800004912 .................29

VHA12K34RTH ................. 80004921 ...................33

VHA12K50RTA .................. 800 04912 ...................29

VHA12K50RTB .................. 800 04 912 ................... 29

VHA12K50RTE .................. 800 04912 ...................29

VHA12K50RTG ................. 80004921 ...................33

VHA12K50RTH ................. 80004921 ...................33

VHA18K25 RTA .................. 80 004 912 ................... 29

VHA18K25RTB .................. 80004912 ...................29

VHA18K25RTC ................. 80004912 ...................29

VHA18K25RTD ................. 80004912 ...................29

VHA18K25RTE .................. 80004912 ...................29

VHA18K25RTG ................. 80004921 ...................33

VHA18K25RTH ................. 80004921 ...................33

VHA18K34RTA .................. 80 004912 ...................29

VHA18K34RTB .................. 800 0 4912 ...................29

VHA18K34RTC .................. 80004912 ...................29

VHA09 K34RTG ................. 800004924 .................36

VHA09 K34RTH ................. 800004924 .................36

VHA09K50RTA ................. 800004912 .................29

VHA09K50RTB ................. 800004912 .................29

VHA09K50RTE ................. 800004912 .................29

VHA09 K50RTG ................. 8 00004924 .................36

VHA09 K50RTH ................. 8 00004924 .................36

VHA12K25RTA .................. 80 004912 ................... 29

VHA12K25RTB .................. 80004912 ...................29

VHA12K25RTE .................. 800 0 4 912 ...................29

VHA12K25RTG ................. 80004921 ...................33

VHA12K25RTH ................. 80004921 ...................33

VHA12K34RTA .................. 800 04912 ...................29

VHA12K34RTB .................. 800 04912 ................... 29

VHA12K34RTE .................. 8000 4912 ................... 29

VHA12K34RTG ................. 80004921 ...................33

VHA18K34RTD ................. 80004912 ...................29

VHA18K34RTE .................. 800 0 4912 ...................29

VHA18K34RTG ................. 80004921 ...................33

VHA18K34RTH ................. 80004921 ...................33

VHA18K50RTA .................. 80 004912 ................... 29

VHA18K50RTB .................. 80004912 ...................29

VHA18K50RTC ................. 80004912 ...................29

VHA18K50RTD ................. 80004912 ...................29

VHA18K50RTE .................. 80004912 ...................29

VHA18K50RTG ................. 80004921 ...................33

VHA18K50RTH ................. 80004921 ...................33

VHA24K10RTH ................. 80110300 ....................39

VHA 24K25RTH ................. 8 011030 0 ....................39

VHA 24K34RTH ................. 80110300 ....................39

VHA 24K50RTH ................. 80110300 ....................3 9

VHA24K75RTH ................. 80110300 ....................39

26

(A - D Suffi x only)

27

28

(A - D Suffi x only)

(A - D Suffi x only)

29

303132333435363738

9-18 ELECTRICAL TROUBLESHOOTING CHART — COOLING

NO COOLING

Insure that Fuses
are good and/or that
Circuit Breakers are

On

O.K.

Compressor runs but

Fan doesn't

Yes

Turn Fan Switch of Room

Thermostat to "On"

position or jump "R" to

"G" at Terminal board

O.K.

Does Fan Motor operate

Is Line Voltage present

Check Capacitor, is

now?

Yes

Problem indicated in
Control wiring and/or

Room Thermostat

at Motor Leads?

Yes

Capacitor Good?

Yes

Motor should run

Fan runs but

Compressor doesn't

No

24Volts at Coil

Terminals of Blower

Relay?

Line Voltage

available at fan

speed switch

(on models so

equipped)

Check Fan

No

No

No

Speed Switch

(on models so equipped)

or Blower Relay on later

models

Replace Capacitor

Possible motor

problem indicated.

Check motor

thoroughly

Yes

Yes

Yes

Set thermostat to

"Cool," move the Temp.

lever below the present

Room Temp.

Compressor and Fan

Motor should now

No

No

No

operate

See Refrigerant Circuit

diagnosis if unit still is

not cooling properly

Problem indicated in

Control Wiring and/

or Room Thermostat

Problems indicated

in Blower Relay

Supply Circuit

problems, loose

Connections, or bad

Relays

Replace Capacitor
and/or Start Assist

Device

Allow ample time

for pressures to

equalize

Possible Compressor

problem indicated.

See Compressor

Checks

O.K.

Yes

Nothing operates,

entire system

appears dead

No

Line voltage present

at the Transformer

24 Volts present at

No

No

No

No

Yes

Primary

Yes

24 Volts at
Transformer
Secondary?

Yes

Cool Relay?

Yes

Fan Motor operates,

but Compressor

doesn't

Is Locked Rotor

Voltage a minimum of

197 Volts?

Are Capacitor and (if

so equipped) Start

Assist good?

Have System

Pressures Equalized?

Compressor should

run

Yes

Yes

Yes

Yes

Check Supply Circuit

for loose connections

No

No

No

or broken wiring

Problems indicated with

Control Transformer

Check Supply Circuit

for loose connections or

broken wiring

Problems indicated with

Room Thermostat or

Control Wiring

Compressor and fan

motor should now

No

See Refrigerant

Circuit Diagnosis if

unit still is not cooling

No

operate

Yes

properly

39

2-TON ELECTRICAL TROUBLESHOOTING CHART — Cooling

NO COOLING

Insure that Fuses
are good and/or that
Circuit Breakers are

On

O.K.

Compressor and outdoor

fan motor run but indoor

blower does not run

Yes

Turn Fan Switch of Room

Thermostat to "On"

position or jump "R" to

"G" at Terminal board

O.K.

Does indoor blower

now operate?

Yes

Problem indicated in
Control wiring and/or

Room Thermostat

Is Line Voltage present

at Motor Leads?

Yes

Check Capacitor, is

Capacitor Good?

Yes

Motor should run

Indoor blower runs but
outdoor fan motor and
compressor do not run

No

24Volts at Coil

Terminals of Blower

Relay?

Line Voltage

available at fan

speed switch

(on models so

equipped)

Check Fan

Speed Switch

(on models so equipped)

No

or Blower Relay on later

models

No

Replace Capacitor

problem indicated.

No

Possible motor

Check motor

thoroughly

Yes

Yes

Yes

Set thermostat to

"Cool," move the Temp.

lever below the present

Room Temp.

Compressor outdoor

fan motor and indoor

blower should now

No

No

No

operate

See Refrigerant Circuit

diagnosis if unit still is

not cooling properly

Problem indicated in

Control Wiring and/

or Room Thermostat

Problems indicated

in Blower Relay

Supply Circuit

problems, loose

Connections, or bad

Relays

Replace Capacitor
and/or Start Assist

Device

Allow ample time

for pressures to

equalize

O.K.

Yes

Nothing operates,

entire system

appears dead

No

Line voltage present

at the Transformer

24 Volts present at

No

No

No

Yes

Primary

Yes

24 Volts at
Transformer
Secondary?

Yes

Cool Relay?

Yes

Outdoor fan motor

operates, but com-

pressor doesn’t

Is Locked Rotor

Voltage a minimum of

197 Volts?

Are Capacitor and (if

so equipped) Start

Assist good?

Have System

Pressures Equalized?

Yes

Yes

Yes

Check Supply Circuit
for loose connections

No

No

No

or broken wiring

Problems indicated with

Control Transformer

Check H.P. Switch is

so equipped

Check Supply Circuit

for loose connections or

broken wiring

Problems indicated with

Room Thermostat or

Control Wiring

Compressor and

outdoor fan motor

should now operate

No

See Refrigerant

Circuit Diagnosis

if unit still is not

cooling properly

No

No

Yes

40

Possible Compressor

problem indicated.

See Compressor

Checks

Compressor should

No

Yes

run

TROUBLESHOOTING CHART — COOLING

REFRIGERANT SYSTEM DIAGNOSIS COOLING

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 High Air Flow Across Refrigerant System Low Air Flow Across
Indoor Coil Indoor Coil Restriction Outdoor Coil

Refrigerant System Reversing Valve not Reversing Valve not
Restriction Fully Seated Fully Seated

Undercharged Overcharged Undercharged

Moisture in System Defective Compressor Defective Compressor

in System

Overcharged

Non-Condensables (air)

TROUBLESHOOTING CHART — HEATING

REFRIGERANT SYSTEM DIAGNOSIS HEATING

Low Suction Pressure High Suction Pressure Low Head Pressure High Head Pressure

Low Air Flow Across Outdoor Ambient Too High Refrigerant System Outdoor Ambient Too High
Outdoor Coil for Operation in Heating Restriction For Operation In Heating

Refrigerant System Reversing Valve not Reversing Valve not Low Air Flow Across
Restriction Fully Seated Fully Seated Indoor Coil

Undercharged Overcharged Undercharged Overcharged

Moisture in System Defective Compressor Defective Compressor

Non-Condensables (air)

in System

41

ELECTRICAL TROUBLESHOOTING CHART

HEAT PUMP

HEAT PUMP

SYSTEM COOLS WHEN

HEATING IS DESIRED.

Is Line Voltage

Present at

Solenoid Valve?

YES

Is the Solenoid

Coil Good?

YES

Reversing Valve Stuck

YES

NO

NO

Is Selector Switch

set for Heat?

Replace Solenoid Coil

42

Replace Reversing Valve

43

Use Factory Certifi ed Parts.

FRIEDRICH AIR CONDITIONING CO.

Post Office Box 1540 · San Antonio, Texas 78295-1540
4200 N. Pan Am Expressway · San Antonio, Texas 78218-5212
[phone] · FAX [phone]
www.friedrich.com

Printed in the U.S.A.

VPSERVMN (4-05)