Koldwave KWV-20, Setup, Operation, And Maintenance Manual

Page: 11 / 12

Subject to change without notice.
11
KWV-20G*ATA**
REV — 02/26/20
TROUBLESHOOTING GUIDE
WARNING: BE AWARE OF HIGH POWER SITUATIONS WHILE TROUBLESHOOTING. THERE ARE
ALSO MOVING BELTS, BLOWERS, AND MOTORS WHILE POWER IS CONNECTED
TO THE UNIT. WHEN REACHING INTO ANY OF THE UNIT SECTIONS TO MAKE
ADJUSTMENTS TO THE UNIT. PLEASE DISCONNECT POWER FROM THE UNIT.
PROBLEM CAUSE DESCRIPTION
Power Lamp
(PL) OFF
1.
No voltage to unit.
1.
Check voltage at power supply and check for broken
power wires.
Power Lamp
(PL) ON
1. No cooling or no blower. 1. Check and/or replace defective selector switch.
2.
Check phase indicator light for correct phasing.
3. Check for defective phase monitor.
Unit Locked in Cooling Mode
1.
Thermostat incorrectly set.
2. Defective thermostat.
3.
Defective compressor contactor CCR.
1.
Check thermostat setting and selector switch mode.
2. Replace thermostat.
3.
Replace compressor contactor CCR.
No Cooling
1. Dirty air filter.
2. Check thermostat setting and mode selector
switch.
3. Defective power wiring to compressor.
4.
Defective compressor contactor CCR.
5. Defective compressor motor
6. Compressor won’t start.
7.
Compression pressures almost equalized.
8. Condenser motor tripped on overload may
have also caused high pressure trip.
1. Clean or replace air filters in front of evaporator coil.
2. Reset thermostat setting or mode selector switch.
3.
Check continuity of power wiring.
4. Replace compressor contactor CCR.
5.
Check motor windings for shorts or opens and/or
replace compressor if necessary.
6. Internal overload opened up. Wait one hour to see if
it resets and starts.
7. Defective compressor valves. Replace compressor.
8.
Reset the overload and also check and reset the
high pressure switch if required.
High Pressure Trips
1.
Condenser air inlet and/or outlets are restricted.
2. High-pressure switch open but doesn’t reset.
3.
Defective condenser blower motor.
4. Defective condenser blower motor contactor
CCR.
5.
System is over-charged or has non-
condensibles.
6.
Condenser blower v-belts loose, slipping, or
broken.
1.
Re-locate unit to a place with unobstructed airflow.
2. Replace high-pressure switch.
3.
Replace condenser blower motor.
4. Replace defective condenser blower motor contactor
CCR.
5.
Remove some refrigerant. If the high side pressure
doesn’t start to drop, recover the refrigerant and re-
charge with fresh R-410a to correct system charge.
6. Re-tighten or replace v-belts.
Low Pressure Trips
1.
Supply and return air grills in space are
restricted.
2. Dirty return air filter.
3.
Low-pressure switch open and does not reset.
4. Defective evaporator blower motor
5.
Defective evaporator blower motor contactor
CEM.
6. System might be under charged check sight
glass and perform leak checks.
7. Expansion valve is sticking or binding.
8.
Filter drier is dirty or plugged.
9. Evaporator blower v-belts loose, slipping, or
broken.
1.
Re-locate objects in front of air grills or re-locate
supply and return air grills in space.
2. Clean or replace air filter.
3.
Replace low-pressure switch.
4. Replace evaporator blower motor.
5.
Replace defective evaporator blower motor
contactor CEM.
6. Recover refrigerant, repair leaks, re-leak check,
evacuate and re-charge to system operating charge
7. Replace expansion valve.
8.
Replace filter drier.
9. Re-tighten or replace v-belts.