York CURBPAK CP23 Installation Operation & Maintenance page 65

MOTOR - EXCESSIVE VOLTAGE DROP
MOTOR - RUNS EXCESSIVELY HOT
MOTOR -WILL NOT START
MOTOR -RUNS NOISY UNDER LOAD
MOTOR – LOAD SPEED CONSIDERABLY
BELOW NAMEPLATE SPEED
MOTOR - EXCESSIVE VIBRATION
MOTOR - NOISY BEARINGS
YORK INTERNATIONAL
Excessive starting or running load. Reduce load or install larger motor.
Inadequate power supply. Consult power company.
Undersized power supply lines. Increase suppIy line sizes.
High resistance connections. Eliminate poor connections.
Motor overloaded. Reduce load or install larger motor.
Blocked ventilation. For OIDP motors blow out internal ventilation pas-
sages with air pressure and eliminate external interference to motor
ventilation. For TEFC motors clean external ventilation system and check
motor ventilation fan.
High ambient temperature over 40°C or 105°C. Reduce ambient tempera-
ture or provide outside source or cooler air.
Unbalanced current draw. Balance supply voltage. Check motor leads for
tightness.
Motor single phase condition. Eliminate single phasing problem.
Motor single phase condition. Shut power off. Eliminate single phasing
condition. Check motor leads for tightness.
Rotor or bearings locked or frozen. Shut power off. Check shaft for freeness
of operation. Replace bearings. Check overload relay sizing and verify
overload relays are in each of the 3 phases of the starter.
Motor single phase condition. If motor cannot be restarted it is single
phased. Eliminate single phasing condition.
Motor single phase condition. Check overload relay sizing and verify
overload relays are in each of the 3 phases of the starter.
Motor shaft bearing damaged. Replace bearing.
Motor overloaded. Reduce load or increase voltage.
Excessively low voltage. A reasonable overload or voltage drop will reduce
motor speed only 1 - 2%. A drop of any greater magnitude would be
questionable.
Inaccurate method of measuring RPM. Check motor using another RPM
measuring device or method.
Motor mounting loose. Check motor mounting and be sure it is tight and
solid.
Load unbalanced. Disconnect belt and restart motor. If vibration stops, the
load is unbalanced. Balance the load.
Remove drive sheave and tape 1/2 key in shaft keyway and restart motor. If
vibration stops the sheave is unbalanced. Replace sheave.
If after checking all other options above and motor still has excessive
vibration, the motor is unbalanced. Replace motor.
Bearing produces smooth mid-range hum. Normal fit, bearing is OK.
High whine. Internal fit of bearing too tight. Replace bearing and check it.
Low rumble. Internal fit of bearing too loose. Replace bearing, check fit.
Rough clatter. Bearing destroyed. Replace bearing. Avoid mechanical
damage, excessive greasing, wrong grease, solid contaminants and
water running into motor.
FORM 100.10-NOM2
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