Friedrich SH20L50-A Air Conditioner User Manual


 
12
TROUBLESHOOTING (Continued)
PROBLEM POSSIBLE CAUSE TO CORRECT
COMPRESSOR
ATTEMPTS TO
START, OR RUNS
FOR SHORT
PERIODS ONLY.
CYCLES ON
OVERLOAD.
Compressor attempts to start
before system pressures are
equalized.
Allow a minimum of two (2) minutes to allow pressures to
equalize before attempting to start.
Low or fl uctuating voltage.
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.
Incorrect wiring. Connect per wiring diagram.
Shorted or incorrect capacitor.
Check by substituting a known good capacitor of correct
rating.
Restricted or low air fl ow through
condenser coil.
Check for proper fan speed or blocked condenser.
Compressor running abnormally
hot.
Check for kinked discharge line or restricted condenser.
Check amperage.
Overload opens too soon.
Change compressor if all other corrections above are
normal.
COMPRESSOR
DOES NOT START -
FAN MOTOR RUNS.
Thermostat contacts not closing.
Check continuity of thermostat at coldest setting. Jump
contacts, if compressor runs, replace thermostat.
Low voltage supply. Check for nameplate voltage.
Switch (On-Off) inoperative. Test for continuity.
Open capacitor.
Check by substituting a known good capacitor of correct
rating.
Internal overload open.
Check voltage at compressor terminals. If voltage is
satisfactory, replace compressor.
Relay open Replace relay
Open or shorted compressor
windings
Check windings for continuity and resistance. Direct test
compressor. If direct test fails, replace compressor.
DOES NOT COOL,
OR COOLS ONLY
SLIGHTLY.
Thermostat open or inoperative.
Set to coldest position. Test thermostat and replace if
necessary.
Dirty air fi lter. Clean as recommended in Owner’s Manual.
Dirty or plugged condenser or
evaporator coil.
Use steam or detergents to clean.
Poor air circulation in area being
cooled.
Adjust air louvers.
Low capacity - undercharge. Clean, check for leak and make repair.
Compressor not pumping
properly.
Check amperage draw against nameplate. If not
conclusive, make pressure test.