Harrington Hoists and Cranes (N)ER Hoist - ((N)ER2) - Manual (Page 48)

48
Table 7-1 Troubleshooting Guide
Symptom Cause Remedy
Hoist will not operate
(continued)
Faulty magnetic
contactor Check coil for open or short circuit. Check all connections in the
control circuit. Check for open contactors. Replace as needed.
Faulty VFD
(dual speed only)
Check fault codes (Reference Section 3.6). Reset VFD by
pressing the Emergency Stop Button on pendant. Replace as
needed.
Faulty Interface Board Replace Interface Board.
Emergency Stop
Depressed on Push
Button Pendant
Control
“Hbb” will appear on the dual speed unit’s VFD display when the
Emergency Stop Button is depressed. Turn the Emergency Stop
Button clockwise to unlock the controls and allow hoist operation.
Defect in control
transformer Check transformer coil for signs of overheating. Disconnect
transformer and check for open winding.
Motor burned out
Replace motor frame/stator, shaft/rotor, and any other damaged
parts.
Hoist lifts but will not
lower
Down circuit open
Check circuit for loose connections. Check down side of limit
switch for malfunction.
Broken conductor in
pendant cord Check the continuity for each conductor in the cable. If one is
broken, replace entire cable.
Faulty magnetic
contactors Check coils for open or short circuit. Check all connections on
motor circuit. Check for burned contacts. Replace as needed.
Faulty VFD
(dual speed only)
Check fault codes (Reference Section 3.6). Reset VFD by
pressing Emergency Stop Button on pendant. Replace as
needed.
Faulty switch in
pendant Check electrical continuity. Check electrical connections.
Replace or repair as needed.
Hoist lowers but will
not lift
Hoist overloaded Reduce load to within rated capacity of hoist.
Low voltage in hoist's
power supply
Determine cause of low voltage and bring to within plus or minus
10% of the voltage specified on the motor nameplate. The
voltage should be measured at the hoist contactor.
Up circuit open
Check circuit for loose connections. Check up side of limit switch
for malfunction.
Broken conductor in
pendant cord Check the continuity of each conductor in the cable. If one is
broken, replace entire cable.
Faulty magnetic
contactor Check coils for open or short circuit. Check all connections on
motor circuit. Check for burned contacts. Replace as needed.
Faulty VFD
(dual speed only)
Check fault codes (Reference Section 3.6). Reset VFD by
pressing Emergency Stop Button on pendant. Replace as
needed.
Faulty switch in
pendant Check electrical continuity. Check electrical connections.
Replace or repair as needed.
Faulty friction clutch Replace.