Mitsubishi Electric M70V Series Connection Manual page 230

(3) Example of surge absorber installation
An example of installing the surge absorber in the machine control panel is shown below.
A short-circuit fault will occur in the surge absorber if a surge exceeding the tolerance is applied. Thus, install a
circuit protection breaker in the stage before the surge absorber. Note that almost no current flows to the surge
absorber during normal use, so a breaker installed as the circuit protection for another device can be used for the
surge absorber.
Panel earth
leakage
Factory power
breaker
Input
power
Grounding
Grounding plate
CAUTION
1. The wires from the surge absorber should be connected without extensions.
2. If the surge absorber cannot be installed just with the enclosed wires, keep the wiring length of A and B to 2m
or less. If the wires are long, the surge absorber's performance may drop and inhibit protection of the devices
in the panel.
3. Surge absorber to be selected varies depending on input power voltage.
Transformer
Circuit
AC reactor
protector
A
Circuit
protector
B
Surge absorber installation
M70V Series Connection Manual
Appendix 2.6 EMC Countermeasure Parts
Circuit
protector
NC unit
Other device
(panel power
supply, etc.)
Contactor
MC
Power supply
unit
and
drive unit
Other device
(panel power
supply, etc.)
(1) Surge absorber
(Protection across phases)
(2) Surge absorber
(Protection across each phase's grounding)
Control panel
(relay panel,
etc.)
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