Leakage Current - YASKAWA SGM Series User Manual

8.3.4 Leakage Current

Since AC Servomotors are driven under high−frequency PWM control, a high−frequency leak-
age current flows through the grounding stray capacitance of the motor winding, power cable,
SERVOPACK, and other devices.
This current may cause a malfunction of the ground fault interrupter or the ground fault protec-
tion relay installed in the power supply curcuit.
When installing a ground fault interrupter, always use a fast−response ground−interrupter or one
designed for PWM inverters so the high−frequency current will not be detected.
The size of the leakage current varies depending on the factors such as the cable length, ambient
temperature, and humidity.
The following table shows the leakage current measured by the resistance method, as described
in the Japan Electrical Manufacturer's Association (JEMA) Standards.
Motor Capacity
30 W to 200 W
Note 1. For 100 V motors, the leakage currents are approximately 1/2 of those in the
table.
2. These currents were obtained using motor power cable whose length is 5 m
or shorter.
400 W
750 W
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8.3 Wiring Specifications
Leakage Current
2 mA to 5 mA
5 mA to 10 mA
10 mA to 15 mA
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