36
37
9.2.5 IGBT excessive current protection
9.2.6 Excessive or too low voltage protection
Check whether the connections between the
outdoor PCB and the IPM are good.
Check whether the IPM is affi xed to
the radiator tightly.
Replace the IPM
Fasten the IPM to the radiator
Replace the compressor
No
Yes
The unit does not work normally
Is the power supply good?
Make sure the power supply is normal
Replace the outdoor e-box
Yes
No
9.2.7 High temperature protection of compressor top
9.2.8 Inverter compressor drive error
9.2.9 Zero crossing detection error
This alarm is triggered when the main chip can’t detect an over-zero signal. When such a failure occurs, the main control board must be faulty.
Does the compressor work?
Is the refrigerant circulation
volume normal?
Is the protector OK?
Replace the outdoor PCB
Replace it
Do the same problems occur
after recharging the gas?
There is a blockage (e.g in the capillary tubing
or at one of the weld points in the pipes)
Is the connection OK?
Re-connect the wiring
No
No
No
Yes
No, Charge refrigerant
Are the connections to the compressor good?
Is the wiring sequence correct? Is the voltage
supply within the correct range?
Re-connect and test again.
Replace the inverter compressor
Replace the outdoor PCB
Yes
No
No
Yes
Yes
E963_Lennox Luna Inverter Service Manual 1d.indd 36-37
E963_Lennox Luna Inverter Service Manual 1d.indd 36-37
14/12/11 12:56 PM
14/12/11 12:56 PM
