
B-65235EN/02 START-UP PROCEDURE 3. START-UP PROCEDURE
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(2) Power requirements
• The power requirement of the servo amplifier
unit is the sum of the power requirements of
individual servo motors.
• When a servo motor accelerates or decelerates
rapidly, it may require twice as much power as
the continuous rating momentarily. Check on the
input voltage required when more than one servo
motor accelarates or decelarates simultaneously,
and keep the voltage above 170VAC for three-
phase input and above 187 VAC for single-phase
input.
• Refer to Chapter 5 in Part III of FANUC SERVO
MOTER β series Description (B-65232EN) for
details of the power requirements.
3.2.2
Leakage Current and Selecting a Ground Fault Interrupter
Because the drive circuit for the servo amplifier unit
operates by a pulse width modulation control system using
IGBTs, high-frequency leakage current flows from the motor
windings and power lines to ground through stray
capacitance. This leakage current may cause the ground
fault interrupter or leakage protection relay installed in the
power line on the power supply side to malfunction. So they
must accommodate leakage from inverters so that they do
not malfunction.
(1) Leakage current from the motor
Determine the leakage current from each motor
according to the table below.
Motor model Leakage current of commercial
power frequency component
β1 to β6,
α0.5 (β0.5) to α2, αC3 to αC6
1.8 mA
αC12
2.0 mA