Mitsubishi Electronics MDS-D-SPJ3 Manuel D’Utilisation

Appendix 4 - 19

An example of installing the surge protector in the machine control panel is shown below.

A short-circuit fault will occur in the surge protector if a surge exceeding the tolerance is applied. Thus, install 

a circuit protector in the stage before the surge protector. Note that almost no current flows to the surge 

protector during normal use, so a circuit protector installed as the circuit protection for another device can be 

used for the surge protector.

Installing the surge absorber

1. The wires from the surge protector should be connected without extensions.

2. If the surge protector 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 protector's performance may drop and inhibit 

protection of the devices in the panel.

3. Surge protector to be selected varies depending on input power voltage.

B 

A 

MC

 

 Circuit
protector 

NC unit

 

Control panel

 

(relay panel,
 etc.)

 

Other device 
(panel power 
supply, etc.)

 

 

Other device 
(panel power 
supply, etc.)

 

 

Panel earth
leakage 
breaker

Input  
power

 

 Circuit
protector

 

AC reactor

 

Transformer

Grounding

Grounding plate

 

Factory power

 

Contactor  

 Circuit
protector 

drive unit

 

 

 

 

 

(1) Surge protector
     (Protection across phases)

(2) Surge protector
     (Protection across each phase's grounding)