Lennox LNIV2610 Service Manual page 19

9.2.5 IGBT excessive current protection
Check whether the connections between the
outdoor PCB and the IPM are good.
Yes
Check whether the IPM is affi xed to
the radiator tightly.
The unit does not work normally
Replace the IPM
9.2.6 Excessive or too low voltage protection
No
Is the power supply good?
Yes
Replace the outdoor e-box
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No
Fasten the IPM to the radiator
Replace the compressor
Make sure the power supply is normal
9.2.7 High temperature protection of compressor top
No
Does the compressor work?
Yes
Is the refrigerant circulation
volume normal?
No, Charge refrigerant
Replace the outdoor PCB
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)
9.2.8 Inverter compressor drive error
Are the connections to the compressor good?
Is the wiring sequence correct? Is the voltage
supply within the correct range?
Yes
No
Replace the outdoor PCB
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.
No
Is the connection OK? Re-connect the wiring
Yes
No
Is the protector OK? Replace it
Yes
No
Re-connect and test again.
Replace the inverter compressor
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