GE VAT20 - Motor Inoperative Troubleshooting

44
(1) Motor inoperative
Is Power LED off ?
Is the circui
t breaker (MCCB)
switched ON?
Wiring short-circuit
Can not
Is the operation
switch on the RUN
position?
Motor over-load
Defective motor
Poor wiring
VAT20 malfunction
VAT20 malfunction
YES
Can you switch ON the
MCCB?
• Power source
abnormality
• Poor wiring
Place the operation
switch to RUN
position.
Is the
T1-T2,T2-T3,T3-T1
output voltage in balance
condition?
ABNORMAL
NO
YES
YES (When the motor is not connected, and the voltoge differences between
wires are within +/- 3% can be treated as in balance condition.)
Normal
(within +/- 10% of nominal value)
NO
NO
Is the
voltage between
L1-L2 power input terminals
normal?
NO
Is there
any output voltage on
motor T1-T2-T3?
VAT20 malfunction
NO