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Symptom Possible cause Test Solution
Overload trips
Motor overloaded Motor is drawing too much current for
the application.
Perform startup and verify motor current
is within specifications. If not, reduce the
load on the motor.
Loose connections Look for signs of overheating on
connections to OL.
Perform pre-startup check for loose
connections and tighten. Replace any
overheated components and wires.
OL not set correctly An improperly set OL can cause the OL
to trip too soon. See pre-startup
procedure for correct setting.
Set correct motor current on OL.
Contactor fails
to pull in
Contamination Remove contactor and check for
contamination.
If contamination is found, repair or
replace.
Defective coil Compare coil resistance to contactor
specification. Inspect the coil for signs
of overheating and damages.
If readings are not the same or if there
are visible signs of damage, replace the
coil or contactor.
Auxiliary contact binding action Remove auxiliary contacts and test
contactor action.
If contactor operates with auxiliaries
removed, replace auxiliary contacts.
Contactor fails
to drop out
Contamination Remove the contactor and check for
contamination.
If contamination is found, repair or
replace.
Defective coil Compare coil resistance to functional
contactors of the same size.
If readings are not the same or there are
visible signs of damage, replace the coil
or contactor.
Auxiliary contact binding action Remove auxiliary contacts and test
contactor action.
If the contactor operates with auxiliaries
removed, replace auxiliary contacts.
Mains current
imbalance
greater than
3%
Problem with mains power Rotate incoming power leads into
option panel one position; A to B, B to
C, and C to A.
If the imbalanced leg follows the wire, it
is a power problem. Causes can vary.
Contact an electrician or power expert
for a solution.
Problem with option panel Rotate incoming power leads into
option panel one position; A to B, B to
C, and C to A.
If the imbalanced leg stays on the same
option panel input terminal, it is a
problem with the option panel. Contact
the factory for assistance.
Motor current
imbalance
greater than
3%
Problem with motor or motor wiring Rotate outgoing motor leads one
position; U to V, V to W, and W to U.
If the imbalanced leg follows the motor
lead, the problem is in the motor or
wiring to the motor. Causes can vary.
Contact an electrician or motor expert
for a solution.
Problem with option panel Rotate outgoing motor leads one
position; U to V, V to W, and W to U.
If the imbalanced leg stays on the same
option panel output terminal, it is a
problem with the option panel. Contact
the factory for assistance.
Start Up Troubleshooting
7-4 BAS-SVX49A-EN