TROUBLE SHOOTING GUIDES
FWR - FWT
PROBLEM PROBABLE CAUSE SOLUTION
Motor Failure (Con't) Motor overloaded a. Check amperage at motor.
b. motor junction box.
If amperage outside of motor nameplate
limits, conduct additional field tests that
follow.
c. Check rotation of fan.
d. Correct rotation, if necessary.
e. Check motor shaft for freedom of movement.
f. Replace motor or motor bearings if
necessary.
g Check for excessive cfm and/or static
pressure.
h. Correct cause of high static pressure and
adjust airflow per start-up section
instructions
Overload. Compare actual amps a. Locate and remove source of excessive friction in
(measured) with nameplate motor or load.
rating b. Reduce load or replace with motor of greater capacity.
Single Phasing a. Check current at all phases (should be approximately
equal) to isolate and correct the problem.
Improper ventilation a. Check external cooling fan to be sure air is moving
properly across cooling fins.
b. Excessive dirt build-up on motor. Clean motor.
Unbalanced voltage a. Check voltage at all phases (should be approximately
equal) to isolate and correct the problem.
Rotor rubbing on stator a. Check air gap clearance and bearings.
b. Tighten “Through Bolts”.
Over voltage or under voltage a. Check input voltage at each phase to motor.
Open stator winding a. Check stator resistance at all three phases for
balance.
Grounded winding a. Perform dielectric test and repair as required.
Improper connections a. Inspect all electrical connections for proper
termination, clearance, mechanical strength and
electrical continuity.
b. Refer to motor lead connection diagram
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