Lennox LGT Series Unit Information page 61

Failure
Locked Rotor
Braking Mode
Hall Error
Power Module Overheated
Motor Overheated
Gate Driver Error
Phase Failure
DC Link Voltage Low
DC Link Over-voltage
Line Over-voltage
Line Under-voltage
Communication Error
DC Link Voltage Low
Electronics Temp High
Power Module Temp High
Motor Temp High
DIRECT DRIVE BLOWER MOTOR TROUBLESHOOTING
Error Warning
No changes in hall signals within
o
Warning, no error code set, Motor
o
start not possible after 20 sec
Combination of 3 hall signals gives
o
false signal after one rotation
o Temperature > 115
Motor over-temperature protector
o
o Internal software fault
o Input voltage has phase imbalance
o Rectified DC link voltage is too low
o Rectified DC link voltage is too high
o Line voltage too high
Line voltage too low
o
Internal communication failure. Not
connected with master/slave wiring
Warning, not low enough to set error
o
Warning, not high enough to set
o
error code, Temperature > 95
Warning, not high enough to set
o
error code, Temperature > 105
Warning, not high enough to set
o
error code, Temperature > 130
TABLE 18
Reason
Check for obstruction keeping impeller from rotating
2000ms
Check for secondary airflow source in the system causing the
Measure voltage across each leg, Check electrical connections
C
o
Check operating conditions in blower compartment, Check for
high motor load (current draw), Check for corrosion-free and
opens
Measure voltage across each leg, Check electrical connections
Measure voltage across each leg, Check electrical
Measure voltage across each leg, Check electrical
code
C
o
Check operating conditions in blower compartment, Check for
high motor load (current draw), Check for corrosion-free and
C
o
C
o
Page 61
Troubleshoot
impeller to rotate backwards when off
secure electrical connections
connections, Repair low/high voltage leg(s)
Check low voltage wiring connections
connections, Repair low/high voltage leg(s)
secure electrical connections