Harrington Hoists and Cranes (N)ER Hoist - ((N)ER2) - Manual (Page 49)

49
Table 7-1 Troubleshooting Guide
Symptom Cause Remedy
Hoist will not lift rated
load or does not have
the proper lifting
speed
Hoist overloaded Reduce load to within rated capacity.
Low voltage in hoist's
power supply
Determine cause of low voltage and bring to within plus or minus
10% of voltage specified on the motor nameplate. The voltage
should be measured at the hoist contactor.
Brake drags/chatters
Check VFD for fault codes. Replace VFD or Interface Board if
needed.
Faulty friction clutch Replace.
Faulty VFD
(dual speed only)
Check fault codes (Reference Section 3.6). Reset VFD by
pressing Emergency Stop Button on pendant. Replace as
needed.
Load drifts
excessively when
hoist is stopped
Motor brake not
holding Check brake for proper “Brake Gap” dimension.
(Reference Table 5-7). Replace if needed.
Mechanical Load
brake not holding (ER2
only)
Replace as needed. (ER2 only, NER2 has no load brake.)
Faulty VFD
(dual speed only)
Check fault codes (Reference Section 3.6). Reset VFD by
pressing Emergency Stop Button on pendant. Replace as
needed.
Motor or brake
overheating
Excessive load Reduce load to within rated capacity of hoist.
Excessive duty cycle Reduce frequency of lifts.
Wrong voltage or
frequency Check voltage and frequency of power supply against the rating
on the nameplate on the motor.
Brake drags/chatters
Check VFD for fault codes. Replace VFD or Interface Board if
needed.
Extreme external
heating
Above an ambient temperature of 140°F, the frequency of hoist
operation must be reduced to avoid overheating of the motor.
Special provisions should be made to ventilate the hoist or
otherwise shield it from the heat.
Hoist operates
intermittently
Collectors making poor
contact Check movement of spring loaded arm, weak spring, connections,
and shoe. Replace as needed.
Contactor contacts
arcing
Check for burned contacts. Replace as needed.
Loose connection in
circuit Check all wires and terminals for bad connections. Replace as
needed.
Broken conductor in
Pendant Cord Check for intermittent continuity in each conductor the Pendant
Cord. Replace entire Pendant Cord if continuity is not constant.
Faulty VFD
(dual speed only)
Check fault codes (Reference Section 3.6). Reset VFD by
pressing Emergency Stop Button on pendant. Replace as
needed.