Troubleshooting - McQuay 5WSS Serie Manual De Instrucciones

• Troubleshooting must be performed by authorized dealer or qualified contractor.
Fault
Unit cannot start
Neither fan coil unit and
compressor run
Compressor does not
operate.
Insufficient cooling
or heating.
Insufficient water flow
through heat exchanger
Noisy operation

TROUBLESHOOTING

1. Power supply plug disconnected.
2. Circuit breaker or fuse tripped / blown.
3. Wiring connection
4. If fault persist, contact your installer.
1. The fuse may be blown or circuit breaker opened.
2. Check electrical circuit or motor winding for shorts or grounds. Investigate for
possible over loading. Replace fuse if necessary.
3. Check wiring connections. Wire may be loosening. Replace or tighten.
4. Control system may be faulty.
1. Check capacitor if available. Replace capacitor if faulty.
2. Check wiring connection. Wire may be loosening. Replace or tighten.
3. The high pressure switch may tripped due to:
a) No or insufficient water flows into and leaves heat exchanger. May be clogged.
b) Water entering temperature higher than the maximum operating conditions.
c) Not enough air flow into fan coil unit. May be due to dirty filter or block by object,
cardboard and etc (heating mode).
d) Fan coil motor failure (heating mode).
e) Unit over-charged. Release some of the refrigerant charge.
4. The compressor internal/external overload protection is opened. If the compressor body
is extremely hot, the overload will not reset until it cooled down.
5. The compressor winding may be grounded to the compressor shell. If so, replace
the compressor.
1. Check controller temperature setting.
2. Filter may be clogged. Check and clean the filter.
3. Check capillary tube for possible restriction of refrigerant flow. Replace capillary tube
if proven so.
4. The reversing valve may be defective (valve position is not shifted properly), creating
a bypass of refrigerant. Check the reversing valve coil connection.
5. Check for restriction of air and water flow.
6. Refrigerant leakage. Check all piping bends and connection for leakage. Repair the
leakage area or replace with new piping.
7. Window or door wide open.
8. Unit may be under-sized.
1. Valves are not opened fully.
2. Circulating water pump is faulty.
3. Water pipes or strainers are clogged.
1. Check for loose bolts or screws.
2. Make sure rubber isolators are used for installation.
3. Check for water balance to unit for proper water flow rate.
4. Check for tubing touching compressor or other surface. Readjust tubing by bending
it slightly.
5. Fan (fan coil unit) knocking / hitting on its housing.
6. May be due to worn compressor bearing.
Cause / Check Point
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