CyberOne EC DX IOM Manual
Symptom
Probable Cause
Recommendation
Suction Pressure Too Low
a. Loss of refrigerant (excessive bubbles in
sight glass).
Locate leak and repair. Recharge system.
b.
Expansion valve stuck or obstructed
(short cycle or continuous running).
Remove and clean or replace valve.
Water/Glycol Valve Fails to Open
or Close
Evaporator Coil Ices
c.
Clogged drier/strainer (feels cold).
Replace with new drier/strainer.
d.
Dirty air filters.
Clean/replace filters.
a.
Temperature set point too high.
Adjust to correct temperature setting.
b.
No control power to the valve.
Thermostat wired incorrectly. Check wiring
diagram and rewire if required.
c.
Actuator failed.
Replace actuator.
1.
Check filters. Replace as needed.
2.
Check for and clear any obstructions
a.
Low airflow.
across or in the (supply) discharge air-
stream.
3.
Check correct rotation of evaporator
blower.
b.
Temperature setting too low.
Increase temperature setpoint (68 °F min.).
c.
Discharge air short cycling back to return. Check discharge grille orientation.
d.
Low refrigerant charge.
Find leak, repair and recharge system.
Blower Fails to Start
a. Power failure.
Check main voltage power source input
cable.
b.
Defective contactor.
Repair or replace.
c.
Condensate Switch Open.
Ensure unit is level.
Check that condensate pan is draining properly.
Clear obstructions.
d.
Motor starter protector tripped
Reset motor starter protector and check am-
perage of motor. Compare to setting of motor
protector and adjust FLA.
e.
Control transformer circuit breaker
tripped
Check for short circuit or ground fault; if none
reset circuit breaker.
f.
No control signal to fan(s).
Check the Control I/O Board for a 0-10
VDC control signal to the fan(s). Refer to the
electric drawing to determine the correct
I/O board terminal numbers. This must BE
done within 15 seconds of turning the
disconnect switch On or the controller will
go into Air Proving Alarm mode.
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