35
P/N: 192047082 (REV AD) 627NH
March 2022
VARIABLE SPEED ELECTRIC CHAIN HOIST WITH
OPTION
TROUBLESHOOTING
Table 11. Troubleshooting
Trouble
Probable Cause
Remedy
1. Hook does not respond to the control
station or control device.
A. No voltage at hoist - main line or branch circuit
switch open; branch line fuse blown or circuit
breaker tripped.
A. Close switch, replace fuse or reset breaker.
B. Phase failure (single phasing, three-phase unit
only) - open circuit, grounded or faulty connection
in one line of supply system, hoist wiring,
reversing contactor, motor leads or windings.
B. Check for electrical continuity and repair or replace
defective part.
C. The upper or lower limits have stopped the hoist
motion.
C. Press the “other” control and the hook should respond.
Adjust limit switches as described on page 19.
D. Wrong voltage or frequency.
D. Use the voltage and frequency indicated on hoist
identification plate.
E. Low voltage.
E. Correct low voltage condition as described on page 11.
F. Brake not releasing - open or shorted coil
winding; armature binding.
F. Check electrical continuity and connections. Check that
correct coil has been installed. Check brake adjustment
as described on page 18.
G. Excessive load.
G. Reduce loading to the capacity limit of hoist as indicated
on the identification plate.
H. Signal connections have unplugged from brake
board.
H. Firmly press the 6- and 13-pin connection plugs into
board. Limits have to be cleared and reset if hoist moves
without encoder input. Verify safe limit operation before
proceeding.
2. Hook moves in wrong direction.
A. Wiring connections reversed at the control
station.
A. Check connections with the wiring diagram.
B. Reversal of motor leads.
B. Refer to installation instructions on page 8.
3. Hook lowers but will not raise.
A. Excessive load.
A. See item 1H.
B. Open hoisting circuit - open; control station
contacts faulty; upper limit position has been
reached.
B. Check electrical continuity and repair or replace defective
part. Check operation of limit switch as described on
page 12.
C. Phase failure.
C. See item 1B.
4. Hook raises but will not lower.
A. Open hoisting circuit - open; control station
contacts faulty; upper limit position has been
reached.
A. Check electrical continuity and repair or replace defective
part. Check operation of limit switch as described on
page 12.
5. Hook lowers when hoisting control is
operated.
A. Phase failure.
A. See item 1B.
B. Phase reversal.
B. Refer to installation instructions on page 11.
6. Hook does not stop promptly.
A. Brake slipping.
A. Check brake adjustment as described on page 18.
B. Excessive load.
B. See item 1H.
