Mitsubishi Electronics FR-S500 instruction manual To-ground leakage currents

Main circuit terminals

1.2.5Leakage current and installation of ground leakage circuit breaker

Due to static capacitances existing in the inverter I/O wiring and motor, leakage currents flow through them. Since their values depend on the static capacitances, carrier frequency, etc., take the following countermeasures.

(1) To-ground leakage currents

Leakage currents may flow not only into the inverter's own line but also into the other line through the ground cable, etc.

These leakage currents may operate ground leakage circuit breakers and ground leakage relays unnecessarily.

Countermeasures

•If the carrier frequency setting is high, decrease the carrier frequency (Pr. 72) of the inverter.

Note that motor noise increases. Selection of Soft-PWM control (Pr. 70) will make it unoffending. (Factory setting)

•By using earth leakage circuit breakers designed for harmonic and surge suppression in the inverter's own line and other line, operation can be performed with the carrier frequency kept high (with low noise).

12