Series 16/18/160/180-Model C Maintenance Manual, GFZ-62755EN ...

B–62755EN/012. HARDWARE Noise suppressorThe AC/DC solenoid and relay are used in the power magnetics cabinet.A high pulse voltage is caused by coil inductance when these devices areturned on or off.This pulse voltage induced through the cable causes the electronic circuitsto be disturbed.To reduce the pulse voltage, use a spark killer for an AC device or a diodefor a DC device.Notes on selecting the spark killerUse a spark killer consisting of a resistor and capacitor in series. This typeof spark killer is called a CR spark killer.(A varistor is useful in clamping the peak voltage of the pulse voltage, butcannot suppress the sudden rise of the pulse voltage. FANUC thereforerecommends a CR spark killer.)The reference capacitance and resistance of the spark killer shall conformto the following based on the current (1(A)) and DC resistance of thestationary coil :1) Resistance (R): Equivalent to DC resistance of the coil2) Capacitance (C):I 210I∼ 2(µF)20Equivalent circuit of the spark killerRCSpark killerAC relayMotorSpark killer129