Werbung
8. Trouble shootings
Before performing any trouble shooting on the chain hoist,
de-energize the supply of electricity as hazardous voltages are
present in the hoist and in connections between components.
Symptom
Loss of power or wrong voltage/frequency
Power cutoff switch cuts off the power
Hoist will not
Motor overheated
operate
Motor burned out
Brake does not release
Improper installation or wearing of carbon
brush
Escape or open circuit of carbon brush lead
Down circuit open
Can lift, but fail
Malfunction of the Down contact of the
to lower
pendant switch
Down circuit open
Hoist overloaded
Considerable voltage drop
Can lower,but
fail to lift
Fault friction clutch
Malfunction of the Up contact of the pendant
switch
Melted B contact of pendant switch
Burnt diode
Burnt D type resistor
Short circuit
Having too much carbon powder on carbon
brush holder
Burnt motor
Hoist overloaded
Considerable voltage drop
Fail to lift the
load rated
Incorrect carbon brush specification or too
short
Burnt, deformation of carbon brush holder
The gap of ratchet brake is too large
Load drifts
excessively when
Malfunction of pressed spring of ratchet brake
hoist is stopped
Improper installation of cap screw
Oil leakage
Damaged or deformed oil packing
Fail to install oil packing
Possible cause
-12-
Remedy
Check power supply against the rating on the
name plate
Reduce load to within rated capacity of hoist
and reset by manual
Take a rest and perform the hoist according to
its duty cycle percentage rated at 25%ED
Replace motor
Check or replace brake assembly
Check or replace carbon brush
Check or replace carbon brush lead
Check down limit switch for malfunction
Replace pendant switch
Check down limit switch for malfunction
Reduce load to within rated capacity of hoist
Applied voltage shall fall into +10% of rated
voltage on the name plate.
If abnormal operation or slippage occurs do
not attempt to disassemble or adjust the
friction clutch. Replace the malfunctioning
friction clutch with a new or factory adjusted
part.
Replace pendant switch
Replace pendant switch
Replace diode and pay attention to its poles
Replace resistor
Disassembly the motor and clean carbon
powder
Replace motor
Reduce load
Applied voltage shall fall into +10% of rated
voltage on the name plate
Replace carbon brush
Replace carbon brush holder
Adjust the ratchet brake
Replace the pressed spring
Proper installation of cap screw
Replace oil packing
Install oil packing
Werbung
