7
SECTION 5 - ELECTRICAL
SECTION 6 - TROUBLESHOOTING
3 PHASE ELECTRICAL DIAGRAM
Recommended Maintenance: Remove dirt accumulations in and around vent openings, by
vacuuming. Dirt accumulations can cause motor overheating and a fire hazard. Enclosed motors
can be cleaned with an air jet; wear eye protection.
Periodically inspect the installation. Check for dirt accumulations; unusual noises or vibration;
overheating; worn or loose couplings, sheaves and belts; high motor current; poor wiring or
overheated connections; loose mounting bolts or guards; and worn motor starter contacts.
WARNING!
Additional wiring will be required to get power to unit, which is not supplied with this product.
Motor Starters, disconnect, wiring, overloads, and thermal protection are NOT provided by the Manufacturer
All Field wiring should be performed by a qualified electrician and must meet all local, NFPA and NEC codes. Failure to install the proper electrical
wiring, thermal protection, and controls will void the warranty.
After completion of the field wiring, turn the unit on to check for proper rotation. Rotation is marked on the side of the blower housing. Backward
rotation will result in a much lower air flow, louder noise, and will over amp the motor. Check the motor nameplate before switching wires and
reversing rotation, to ensure the unit is operating at or below rated amp draw.
This chart suggests common answers to electric motor problems. The information is not all-inclusive and does not necessarily apply in all cases.
When unusual operating conditions, repetitive failures, or other problems occur, consult an electric motor service firm for assistance.
Symptom Possible Cause(s) Corrective Action
Motor fails to start
1. Blown fuses
2. Voltage too low at motor terminals due to line drop
3. Overload in motor starter tripped
4. Overload (internal thermal protector) tripped
5. Improper line connections
6. Motor may be overloaded
7. Defective motor or starter.
1. Replace with time-delay fuses. Check for grounded
winding
2. Consult local power company. Increase wire size (refer to
Tables A & B). Check for poor connections
3. Check and reset overload relay in starter. Check heater
rating against motor nameplate current rating
4. Check motor load. If motor has an automatic or manual
reset thermal protector, check if tripped
5. Check connections against diagram supplied with motor
6. Reduce load or increase motor size
7. Repair or replace
Motor does not come
up to speed or takes too
long to accelerate
1. Not applied properly.
2. Voltage too low at motor terminals
3. Starting load too high.
4. Excess loading; tight belts
5. Defective motor
6. Inadequate starting torque. High inertia load
1. Consult motor service firm for proper type. Use larger
motor.
2. Increase wire size (refer to Tables A & B). Check for poor
connections. Check for voltage unbalance (3-Phase)
3. Check load motor is carrying at start.
4. Reduce load; adjust belts. Increase motor size.
5. Repair or replace
6. Replace with larger motor
Motor stalls during
operation
1. Overloaded motor
2. Low motor voltage
1. Reduce load or increase motor size
2. Verify that nameplate voltage is maintained
6.1 Troubleshooting Chart
