19
Subject to change without notice.
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.
No Condenser Blower Operation
1.
Tripped Condenser Motor Contactor
Overload.
1.
Condenser blower motor moving too much air
due to no blower ducting attached. Close off
damper slide plate.
2.
If access panels are off of unit, replace access
panels.
UCA021 (0618)
