20
TROUBLE-SHOOTING
HOIST TROUBLE-SHOOTING
Condition
Troubles
Trouble-shooting methods
Doesn’t start
Electric power is property
supplied
Doesn’t start when pressing
hoisting and lowering
push- buttons.
Press the buttons hard.
Polish or clean the contact points.
Repair the control cable that
may be disconnected or faulty
contacts of the terminals.
Reverse performance of hoisting
& lowering push- buttons.
The contact of the limit switch
is disconnected, place the limit
handle to the normal position.
The motor hums or gets
overheated.
Repair disconnection of the
power source cable or bring the
cords connections to perfection.
Poor starting and drop of power
Single-phase operation
The motor hums or
temperture rises.
Use the correct voltage. Replace
faulty power source switch,
cable or fuse.
Motor stops occasionally in
operation
Limit switch turns off
Twist of the load chains or their
tangle causes the limit handle to
push up unintentionaly, when
pulling a load excessively at angle.
Position the load chains properly.
Lift the load vertically.
Replace the limit handle to proper
position.
Faulty contact
lntermittent or irregular operati-
on due to ineffective contact at
power source cable, terminal or
switches.
Have the faulty contactor
replaced by a person qualified to
perform hoist maintenance.
Overloading
The motor hums and over current
arises.
Lift loads within the rated load.
lneffective braking
Poor braking
Due to wear of the brake lining
on the brake wheel.
Have the faulty contactor
replaced by a person qualified to
perform hoist maintenance.
Slipping slowly all the way down
Mechanical brake.
Electrical accidents
Leak
The hoist generates electric shock
when touching metal
components.
The hoist should be earthed
effectively. Examine insulation
resistance . lnspect switches to
ensure that they are not moiste-
ned-keep them dry.
Table 13
