McQuay M5CKY28ER User Manual

M5LCY-II_(i) Troubleshooting
51
Error Codes Error Description Action
J5 Suction pipe thermistor short / open
Same as H9.
J6 Outdoor heat exchanger
J7
Subcooling heat exchanger
thermistor short/open
J8 Liquid pipe thermistor short/open
J9 Gas pipe thermistor abnormality
LC
Communication Error
(control PCB and inverter PCB)
1. Check fan motor connection.
2. Check if LED blinking normally at outdoor PCB.
L1 Outdoor PCB error
1. Check the range of power supply.
2. Check connection between compressor and PCB.
3. Check fan motor resistance.
4. Check the power supply waveform.
L3 Electrical box temperature rise
1. Restart the system.
2. Check sensor resistance value.
3. Check heat sink temperature and conditions.
4. Check outdoor fan.
5. Check the installation condition.
L4 Heat sink overheat
1. Restart the system.
2. Check the silicon grease condition on heat sink.
3. Check sensor resistance value.
4. Check heat sink temperature and conditions.
5. Check outdoor fan.
6. Check the installation condition.
L5 IPM error / IGBT error
1. Check stop valve.
2. Check with inverter checker.
3. Check the power transistor and supply voltage.
5. Check the compressor phase.
6. Check the discharge pressure.
7. Check the installation condition.
L8 Electrical thermal switch Contact dealers for assistance.
L9 Stall prevention
1. Check installation conditions.
2. Check stop valve.
3. Check difference between high and low pressure
side.
4. Check continuity on the power transistor.
5. Check the output voltage.
P1 Open phase or voltage unbalance
1. Check LED on outdoor PCB.
2. Check open phase of power supply voltage.
3. Check voltage balance between phases.
P4 Heat sink thermistor short / open Same as H9.
PJ Capacity setting error
1. Check the connection between capacitor and
outdoor PCB.

McQuay M5CKY28ER Specifications

General

Brand	McQuay
Model	M5CKY28ER
Category	Air Conditioner
Language	English