Hitachi L Series, Service Manual

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5. Cautions for use
CAUTION
•
When it operates in the opposite direction to the push-button operation, switch the phase
sequence of the power supply or review the motor wiring and operation input wiring referring
to the connection diagram.
1. After installing the Electric chain hoist, please ensure to do a trial run following the attached "Hitachi Electric
chain hoist Owner's Manual".
2. Please avoid sudden reverse rotation (plugging) or excessive small motions (inching). These will put an
excessive load on the contacts of the motor and the electromagnetic contactor and decrease the product life.
3. If operated exceeded the ratings, the temperature of various parts of the Electric chain hoist will rise above the
allowable limit, causing burnout of the motor and shortening the lifetime of the mechanical parts. Even when
using over a short time in a concentrated manner, please do not exceed the prescribed start frequency and
duty factor for each model.
Example) When using the L-type (single speed) for 15 minutes in a concentrated way, set the start frequency
at 60 times / 15 minutes or less, and duty factor at 40% ED or less.
•
The start frequency is the number of times the push-button switch is pressed per hour (including inching).
•
Calculate the duty factor using the following formula.
Duty factor (%) =
×100
In the hour when the Electric chain hoist is used the most,
the total time (minutes) the motor is powered
60 (minutes)