McQuay M5MSY18BR User Manual

47
Troubleshooting M5MSY_(i)
Error
Codes
Error Description Action
H8 AC current sensor error
1. Restart the system.
2. Check capacitor voltage.
3. Measure the rectifi er input voltage.
4. Check compressor harness wire.
5. Check with inverter checker.
H9 Outdoor air thermistor short / open
1. Check the sensor connection.
2. Check the sensor resistance value.
J1 Pressure sensor error
1. Check pressure sensor connection.
2. Check pressure and voltage level.
J3
Compressor discharge pipe ther-
mistor short /open / misplaced
1. Check the sensor connection.
2. Check the sensor resistance value.
3. Check indoor coil sensor resistance value.
J5 Suction pipe thermistor short/ open Same as H9.
J6 Outdoor heat exchanger Same as H9.
J7
Subcooling heat exchanger
thermistor short/ open
Same as H9.
J8 Liquid pipe thermistor short/ open Same as H9.
J9 Gas pipe thermistor abnormality Same as H9.
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.
4. Check the 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 M5MSY18BR Specifications

General

Brand	McQuay
Model	M5MSY18BR
Category	Air Conditioner
Language	English