
21
Incorrect or missing input voltage
Incorrect or missing DC bus voltage
Remote control wiring loading the power supply
Defective Control Card
Defective Interface Board
Defective or disconnected ribbon cables
Shorted SCR/Diode module
Shorted IGBT
Shorted soft charge rectifier
Shorted DC bus
Shorted brake IGBT
Mis-wired Dynamic Brake option
Start compensation set too high
Slip Compensation set too high
Improper current feedback
PID Regulator or Auxilary Reference misadjusted
Open winding in motor
Open connection to motor
One inverter phase missing. Test output phase balance, page 27.
One half of one inverter phase missing. Test output phase balance,
page 27.
6.
Motor Runs Unloaded But Stalls
When Loaded. (Motor may run rough
and VLT may trip.)
1.
Control Card Display Is Not Lit.
2.
Blown Input Line Fuses
3.
Blown Soft Charge Fuses
4.
Motor Operation Unstable (Speed
Fluctuating)
5.
Motor Draws High Current But
Cannot Start. (May appear to rock
back and forth.)
SYMPTOM/CAUSE CHARTS
SYMPTOM/CAUSE charts are generally directed towards the more experienced technician. The intent of these
charts is to provide a range of possible causes for a specific symptom. In doing so, these charts provide a direction,
but with limited instruction.
SYMPTOM
POSSIBLE CAUSES