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Maintenance
AH-SVX008C-EN
41
Troubleshooting
Troubleshooting steps are listed in the following table.
Turn off all power to the unit before conducting any
troubleshooting procedures unless the procedure
specifically requires the system to operate. Keep hands,
clothing and tools clear of the electrical terminals and
rotating components. Equipment located in the ceiling can
pose unusual difficulties. Ensure that your footing is stable
at all times.
Table 10. Troubleshooting methods
Symptom
Probable Cause
Recommendation
Suction Pressure Too Low
a. Loss of refrigerant (excessive bubbles in
sight glass).
Locate and repair leak. Remove and clean or
replace valve.
b. Expansion valve stuck or obstructed (short
cycle or continuous running).
c. Clogged drier/strainer (feels cold).
Replace with new drier/strainer.
d. Dirty air filters.
Clean/replace filters.
Chilled Water Valve Fails to Open or Close
a. Temperature setpoint too high/low.
Adjust to correct temperature setting
b. No control power to the chilled water valve
Thermostat wired incorrectly. Check wiring
diagram and rewire if required.
c. Actuator failed.
Replace actuator.
Evaporator Coil Ices
Low airflow.
1.Check filters. Replace as needed.
2.Check for and clear any obstructions 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
minimum.).
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. Control transformer circuit breaker tripped.
Check for short circuit or ground fault; if none,
reset circuit breaker.
c. Defective contactor. Repair or replace.
Repair or replace.
d.Thermal overload tripped.
Reset overload and check amperage of motor.
Compare to setting on overload and adjust to
FLA. All direct-drive motors are internally
protected and do not require overload reset.
Control is Erratic
Wiring improperly connected or broken.
Check wiring against electrical drawing.
Condenser Pressure Too High
a. Non-condensable gas or air in system.
Recover system and recharge. Replace
drier/strainer. Evacuate to 50 microns and
recharge.
b. Condenser air intake is blocked
Remove debris and clean condenser.
c. Overcharge of refrigerant
Reclaim excess refrigerant from system.
d. Low water flow to water-cooled condenser
Reset-determine cause and fix.
e. Condenser fan not operating
Check pressure/temperature operating
switches and motor. Replace as needed.
f. Water/glycol temperature too high.
Check flow and operation of drycooler.
g. Condenser pressure regulating valve setting
too high
Adjust to obtain correct pressure.
h. Flow of water/glycol too low
1.Check glycol solution level and concentration.
2.Valves not open or partially open. Repair/
replace as needed.
3.Air in system - bleed system.
4.Check all strainers and clean if needed.
i. Water/glycol solution not mixed prior to
adding to syste
Remove solution and premix. Refill system.
Condenser Pressure Too Low
a. Loss of refrigerant (indicated bubbles in sight
glass).
Locate and repair leak. Recharge
b. Condenser fan controls not set.
Adjust or repair controls
c.Water regulating valve adjusted too low.
R407C - Readjust to 320 psig.
Summary of Contents for CeilAir CW
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