Friedrich SH20J30B-A Air Conditioner User Manual


 
12
PROBLEM POSSIBLE CAUSE TO CORRECT
Compressor
attempts to
start, or runs
for short
periods only.
Cycles on
overload.
Allow a minimum of two (2) minutes to allow pressures to
equalize before attempting to start.
Check voltage with unit operating. Check for other appliances
on the circuit. Unit should be on separate circuit for proper
voltage, and be fused separately.
Connect per wiring diagram.
Check by substituting a known good capacitor of correct rating.
Check for proper fan speed or blocked condenser.
Check for kinked discharge line or restricted condenser. Check
amperage.
Change compressor if all other corrections above are normal.
Compressor attempts to start
before system pressures are
equalized.
Low or fluctuating voltage.
Incorrect wiring.
Shorted or incorrect capacitor.
Restricted or low air flow through
condenser coil.
Compressor running abnormally
hot.
Overload opens too soon.
PROBLEM POSSIBLE CAUSE TO CORRECT
Compressor
does not
start - fan
motor
runs.
Check continuity of thermostat at coldest setting. Jump
contacts, if compressor runs, replace thermostat.
Check for nameplate voltage.
Test for continuity.
Check by substituting a known good capacitor of correct rating.
Check voltage at compressor terminals. If voltage is satisfactory,
replace compressor.
Check windings for continuity and resistance. Direct test
compressor. If direct test fails, replace compressor.
Thermostat contacts not closing.
Low voltage supply.
Switch (On-Off) inoperative.
Open capacitor.
Internal overload open.
Open or shorted compressor
windings
PROBLEM POSSIBLE CAUSE TO CORRECT
Set to coldest position. Test thermostat and replace if
necessary.
Clean as recommended in Owners Manual.
Use steam or detergents to clean.
Adjust air louvers.
Clean, check for leak and make repair.
Check amperage draw against nameplate. If not conclusive,
make pressure test.
Thermostat open or inoperative.
Dirty air filter.
Dirty or plugged condenser or
evaporator coil.
Poor air circulation in area being
cooled.
Low capacity - undercharge.
Compressor not pumping
properly.
Does not
cool, or
cools only
slightly
Fan motor
does not
run.
PROBLEM POSSIBLE CAUSE TO CORRECT
Check continuity across terminals 2 and 3.
Check by substituting a known good capacitor of the same
rating.
Direct test fan motor.
Connect per wiring diagram.
Replace Relay.
Rotate by hand, add oil, if noisy, replace.
Adjust for proper clearance.
Defective switch (On-Off).
Fan capacitor open.
Inoperative fan motor.
Incorrect wiring of fan circuit.
Relay open.
Check for seized motor bearings.
Bound fan blade or blower wheel.
TROUBLESHOOTING (Continued)