Trane TR200 Operator's Manual page 71

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