2-Ton Electrical Troubleshooting Chart - Cooling - Friedrich 000 BTU'S Service Manual

ELECtRICaL tRoUBLESHootIng CHaRt - CooLIng
Compressor and outdoor
fan motor run but indoor
blower does not run
Yes
24V at t-stat and 24V at t-stat and
control wiring? control wiring?
No No
Yes Yes
Yes
Is Line Voltage present
at Motor Leads?
No
Yes
Check Capacitor, is
Capacitor Good?
No
Yes
Motor should run
No
24k BtU
NO COOLING OPERATION
are good and/or that
Circuit Breakers are
on and voltage is 208/230
"Cool," move the Temp.
lever below the present
Compressor outdoor
Indoor blower runs but
fan motor and indoor
outdoor fan motor and
blower should now
No
compressor do not run
Yes
See Refrigerant Circuit
diagnosis if unit still is
not cooling properly
Defective t-stat
defective control wiring
or transformer
Problems indicated
in Blower Relay
of board
Replace Capacitor
Possible motor
problem indicated.
Check motor
thoroughly
Before continuing
check for Error
Insure that Fuses
Codes, see
electronics control
diagnostics and
test mode, page 15
O.K.
Set thermostat to
Nothing operates,
entire system
appears dead
Room Temp.
No
O.K.
Line voltage present
at the Transformer
operate
Yes
"R" Terminal on board
24 Volts present at
Y terminals on
t-stat and board?
208/230 Volts present
at #1 relay and "OD"
terminal on board?
208/230 Volts present
at compressor's
Supply Circuit
problems, loose
Voltage a minimum of
Connections, or bad
Relays/Board No
Replace Capacitor
Are Capacitor and (if
and/or Start Assist
Device
No
Allow ample time
for pressures to
Pressures Equalized?
equalize No
Possible Compressor
problem indicated.
Compressor should
See Compressor
No
Checks
Yes
Check Supply Circuit's
jumper at transformer. If
okay, replace board
Primary
No
Yes
Problems indicated with
24 Volts at
Control Transformer
replace board
No
Yes Yes
Problems indicated with
Room Thermostat or
No Control Wiring
Yes
Yes
Replace board
No
Yes
Check contactor
If defective replace
contactor? No
Yes
Compressor and
outdoor fan motor
should now operate
No
Is Locked Rotor
See Refrigerant
Circuit Diagnosis
197 Volts?
if unit still is not
cooling properly
Yes
so equipped) Start
Assist good?
Yes
Have System
Yes
run
Yes
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