3.2 Electrical specifications
3-8
3. Wiring
Selection of circuit breaker
For the selection of the circuit breaker, perform it according to the following items.
● 3 times of the rated current flows to the controller during the acceleration/deceleration.
Select an interrupter that does not trip with this value of current. If a trip occurs, select an
interrupter that possesses the rated current of one grade higher. (Check the operation
characteristics curves in the product catalog.)
● Select an interrupter that does not trip with the in-rush current. (Check the operation
characteristics curves in the product catalog.)
● Consider the current that enables to cutoff the current even when a short circuit current is
flown for the rated cutoff current.
Rated interrupting current > Short circuit current = Primary power capacity / Power voltage
● Consider margin for the rated current on the circuit breaker.
Rated current for circuit breaker >
Motor power capacity [VA] / AC input voltage × Safety margin (1.2 to 1.4 times)
Selection of leak current breaker
● A ground fault circuit interrupter needs to be selected carefully considering the purposes of
prevention of fire and protection of human.
● Leak current varies depending on the motor wattage, cable length and the surrounding
environment. Measure the leak current at the point where a ground fault circuit interrupter is
to be installed when leakage protection is conducted.
● For the leakage breaker, use a harmonic applicable type.
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