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

ELECtRICaL tRoUBLESHootIng CHaRt - CooLIng

Compressor runs but
Blower/Fan doesn't
Yes
24V at t-stat and
control wiring?
Yes
Is Line Voltage present
at Motor Leads?
Yes
Check Capacitor, is
Capacitor Good?
Yes
Motor should run
40
9k BtU, 12k BtU, & 18k BtU
NO COOLING OPERATION
Fan runs but
Compressor doesn't
No
Yes
Defective t-stat
defective control wiring
No
or transformer
Problems indicated
in Blower Relay
No
of board
Replace Capacitor
No
Possible motor
problem indicated.
Check motor
No
thoroughly
Before continuing
Insure that Fuses
are good and/or that
electronics control
Circuit Breakers are
on and voltage is 208/230
test mode, page 15
O.K.
Set thermostat to
"Cool," and the Temp.
below the present
Room Temp.
No
O.K.
Line voltage present
Compressor and Fan
Motor should now
operate
Yes
See Refrigerant Circuit
"R" Terminal on board
diagnosis if unit still is
not cooling properly
208/230 Volts present
at #1 relay on board?
Supply Circuit
problems, loose
Connections, or bad
No
Relays/Board
Replace Capacitor
and/or Start Assist
Device
No
Allow ample time
for pressures to
No
equalize
Possible Compressor
problem indicated.
See Compressor
No
Checks
check for Error
Codes, see
diagnostics and
Nothing operates,
entire system
appears dead
Yes
Check Supply Circuit's
jumper at transformer. If
at the Transformer
okay, replace board
Primary
No
Yes
Problems indicated with
24 Volts at
Control Transformer
No
Yes
24 Volts present at Problems indicated with
Room Thermostat or
Y terminals on
No
t-stat and board?
Yes
No
Yes
No
Is Locked Rotor
Voltage a minimum of
197 Volts?
Yes
Are Capacitor and (if
so equipped) Start
Assist good?
Yes
Have System
Pressures Equalized?
Yes
Compressor should
run
replace board
Control Wiring
Replace board
Yes
Compressor and fan
motor should now
operate
Yes
See Refrigerant
Circuit Diagnosis if
unit still is not cooling
properly