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

2-TON 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 outdoor

Compressor and outdoor

Indoor blower runs but

at the Transformer

for loose connections

fan motor run but indoor

outdoor fan motor and

fan motor and indoor

No

blower does not run

compressor do not run

No

blower should now

Primary

or broken wiring

operate

Yes

Yes

Yes

Yes

24 Volts at

Problems indicated with

Turn Fan Switch of Room

See Refrigerant Circuit

Transformer

No

Thermostat to "On"

Secondary?

Control Transformer

position or jump "R" to

diagnosis if unit still is

not cooling properly

Yes

"G" at Terminal board

24 Volts present at

Check H.P. Switch is

O.K.

Cool Relay?

No

so equipped

Yes

No

Check Supply Circuit

Does indoor blower

for loose connections or

broken wiring

now operate?

No

Problem indicated in

No

24Volts at Coil

Yes

Control Wiring and/

Terminals of Blower

or Room Thermostat

Problems indicated with

Relay?

No

Problem indicated in

Room Thermostat or

Control Wiring

Control wiring and/or

Yes

Room Thermostat

Line Voltage

Problems indicated

available at fan

No

in Blower Relay

speed switch

(on models so

equipped)

Yes

Outdoor fan motor

Compressor and

operates, but com-

outdoor fan motor

No

pressor doesn’t

should now operate

Is Line Voltage present

Check Fan

Yes

Yes

at Motor Leads?

Speed Switch

No

(on models so equipped)

Supply Circuit

Yes

or Blower Relay on later

problems, loose

Is Locked Rotor

See Refrigerant

models

Connections, or bad

Voltage a minimum of

Circuit Diagnosis

Relays

No

197 Volts?

if unit still is not

Yes

cooling 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

See Compressor

No

run

Checks

40