Friedrich V(E, H)A09K25 service manual Electrical Troubleshooting Chart Cooling

9-18 ELECTRICAL TROUBLESHOOTING CHART — COOLING

NO COOLING

Insure that Fuses

are good and/or that Circuit Breakers are On

O.K.

Set thermostat to

Nothing operates,

"Cool," move the Temp.

entire system

lever below the present

appears dead

Room Temp.

O.K.

No

Yes

Line voltage present

Check Supply Circuit

Compressor and Fan

Compressor runs but

Fan runs but

Motor should now

at the Transformer

No

for loose connections

Fan doesn't

Compressor doesn't

No

operate

Primary

or broken wiring

Yes

Yes

Yes

Yes

24 Volts at

Problems indicated with

Turn Fan Switch of Room

See Refrigerant Circuit

Transformer

Thermostat to "On"

diagnosis if unit still is

Secondary?

No

Control Transformer

position or jump "R" to

not cooling properly

Yes

"G" at Terminal board

O.K.

24 Volts present at

Check Supply Circuit

Cool Relay?

No

for loose connections or

broken wiring

Yes

No

Problems indicated with

Does Fan Motor operate

Room Thermostat or

Control Wiring

now?

No

Problem indicated in

24Volts at Coil

Yes

Control Wiring and/

Terminals of Blower

No

or Room Thermostat

Relay?

Problem indicated in

Yes

Control wiring and/or

Room Thermostat

Line Voltage

Problems indicated

available at fan

No

in Blower Relay

speed switch

(on models so

equipped)

Yes

Fan Motor operates,

Compressor and fan

but Compressor

No

motor should now

doesn't

operate

Is Line Voltage present

Check Fan

Yes

Yes

at Motor Leads?

No

Speed Switch

(on models so equipped)

Supply Circuit

Is Locked Rotor

Yes

or Blower Relay on later

problems, loose

See Refrigerant

models

Connections, or bad

Voltage a minimum of

Circuit Diagnosis if

Relays

No

197 Volts?

unit still is not cooling

Yes

properly

Check Capacitor, is

Replace Capacitor

Capacitor Good?

No

Replace Capacitor

Are Capacitor and (if

and/or Start Assist

so equipped) Start

Yes

Device

No

Assist good?

Possible motor

Yes

Motor should run

problem indicated.

No

Check motor

thoroughly

Allow ample time

Have System

for pressures to

No

Pressures Equalized?

equalize

Yes

Possible Compressor

problem indicated.

Compressor should

No

See Compressor

run

Checks

39