CM-ET Lodestar - Manual (Page 19)

15
TROUBLE SHOOTING
All Hoists
Table 8.
TROUBLE PROBABLE CAUSE CHECK AND 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 electical continuity and repair or
replace defective part.
C.) Upper or lower limit switch has opened
the control circuit.
C.) Press the “other” control and the hook
should respond. Adjust limit switches as
described on page 12.
D.) Open control circuit-open or shorted
winding in transformer, reversing contactor
coil or loose connection or broken wire in
circuit;mechanical binding in contactor
control station contacts not closing or
opening.
D.) Check electrical continuity and repair or
replace defective part.
E.) Wrong voltage or frequency.. E.) Use the voltage and frequency indicated on
hoist identification plate.
For three phase dual voltage unit, make
sure the connections at the voltage change
board are the proper voltage as
described on page 5.
F.) Low Voltage. F.) Correct low voltage condition as described
on page 5.
G.) Brake not releasing-open or shorted coil
winding; armature binding.
G.) Check electrical continutiy and connections.
Check that correct coil has been installed.
The coil for three phase dual voltage unit
operates at 230 volts when the hoist is
connected for either 230 volt or 460 volt
operation. Check brake adjustment as
described on page 11.
H.) Excessive load. H.) Reduce loading to the capacity limit of hoist
as indicated on the identifcation plate.
2.) Hook moves in wrong
direction.
A.) Phase reversal (three phase unit only). A.) Refer to installation instruction on page 8.
3.) Hook lowers but will not
raise.
A.) Excessive load. A.) See item 1H.
B.) Open hoisting circuit-open or shorted
winding in reversing contactor coil loose
connection or broken wire in circuit; control
station contacts not making; upper limit
switch contacts open.
B.) Check electrical continuity and repair or
replace defective part. Check operation of
limit switch as described on page 10.
C.) Phase failure (three phase unit only). C.) See item 1B.