ABB PST - Page 165

Low Voltage Products & Systems 165
ABB Inc. • 888-385-1221 • www.abb-control.com AC 1006.9 - 5/03
Chapter 11 - Troubleshooting
Status Possible cause
Underload protection • Check and correct the reason for
the underload.
• Check that the settings are
according to the operation
conditions.
Locked rotor protection • Check the bearings of the motor
and load.
• Check that the load is not running
stiff.
High current protection • Check the circuits including the
motor for any insulation fault, phase
to phase or ground fault.
Phase imbalance protection • Check the main voltage and the
motor circuit.
• Restart the motor and check the
phase currents.
Phase reversal protection • Check the phase sequence on the
line side to (L1-L2-L3).
A fault current, higher than 8 times
the softstarter rating has occurred.
Unbalance in the phase currents.
The phase sequence is not
correct.
Solution
The motor current is below set
level and time.
The motor is running stiff for some
reason.
A damaged bearing or a stuck
load could be possible causes.
Power on ProtectionFault
Prot Underload
Reset Back
Power on ProtectionFault
Prot Locked Rot
Reset Back
Power on ProtectionFault
Prot High I
Reset Back
Power on ProtectionFault
Prot Phase Imb.
Reset Back
Power on ProtectionFault
Prot Phase Rev
Reset Back