Mitsubishi Electric CNC 700 Series Connection Manual page 183

Appendix 1. EMC Installation Guidelines
Example of surge absorber installation
Panel
From
leakage
power supply
breaker
200VAC
/230VAC
input
Ground
Precautions
(1) Use a thick wire that is as short as possible to increase the lightning surge absorbing effect as shown
with the bold lines in the installation example above.
Wire material :
Wire length
(2) When carrying out the insulation withstand voltage test on the power supply line, the surge absorber will
activate by the applied voltage, so always remove surge absorber (b).
(3) If a surge exceeding the tolerance is applied on the surge absorber, a short-circuit fault will occur. Thus,
always insert a circuit protector to protect the power supply line.
Normally, current is not passed to the surge absorber (a) and (b), so the circuit protector can be used for
the other devices.
Transformer
Circuit
MC
breaker
A
Circuit protector
Surge absorber (a)
Grounding plate
Example of surge absorber installation
2
Diameter 2mm or more
Length of wire connected to surge absorber (a) : A is 2m or less
Length of wire connected to surge absorber (b) : B is 2m or less
Length of wire connected to surge absorber (b) : C is 2m or less
1.6 EMC Countermeasure Parts
Circuit breaker
NC control
section
Other devices
(panel power
supply, etc.)
Reactor
NC drive
section
B
Other devices
(panel power
supply, etc.)
Surge absorber (b)
C
164
Control panel
(relay panel,
etc.)