Harrington Hoists and Cranes SH Hoist - Manual (Page 5)

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7-2 ELECTRICAL WIRING
The Single phase hoist is to be used on single phase electrical power source (110 or 220 volt).
Compared with conventional home electrical equipment, a large capacity motor is used on the
hoist. Consult you local electric codes for proper wiring of the single phase hoist.
a) Connect RED and WHITE lead wires of the power supply cable to the switch in the main
switch box. Cables must be securely connected for safe operation.
b) Ground wiring
The GREEN wire with YELLOW stripe is the ground wire. This wire should always be
connected to a suitable ground. Unless the wire is grounded, operators may sometimes
feel a shock when touching any part of the hoist or chain. Do not paint the trolley running
surface of the beam when electrical grounding work is not provided on the copper
conductor.
c) Connection by wall outlet and plug
The best way of connection to power source is directly from power supply cable to main
power switch. When using a plug, it must be grounded.
8. NOTES ON TRIAL OPERATION
After initial installation of the hoist and before each day's use, perform a trial operation to
ensure the hoist functions properly.
a) Check voltage supply before each day's use. IF the voltage is not within plus or minus 10%
of the rated value, electrical devices may not function properly.
b) Check the control button. The depression of "UP" button must lift the load chain and the
depression of the "DOWN" button must lower the chain.
TIPS FOR SAFE OPERATION
1. FRICTION CLUTCH
The SH electric chain hoist is equipped with a built-in friction clutch as the overwinding
protection device. This clutch eliminated complex electrical circuitry and its simple
construction reduces trouble to a minimum.
a) Do not overload the hoist.
The friction clutch is not an overload protection device. The load to be lifted must be
within the capacity of the hoist. When the hoist is overloaded in excess of the slip torque,
the friction clutch slips allowing the motor to run freely, protecting the other parts. However,
if the hoist is overloaded close to the slip torque and if the load is forcibly lifted with the
clutch slipping, the lifted load may fail.
b) Do not overwind the hoist
The friction clutch will slip allowing the motor to run free when either the rubber cushion
hits the load chain guide or when the chain is overlifted or overlowered. However, do not
use this safety device as a means to stop the hoist.
c) Do not readjust the setting of friction clutch
The clutch is preset to function correctly before the hoist leaves the factory. Do not attempt
to readjust the clutch setting in the field.