Chapter 3   Ambient Environment and Installation 
3-7 
Make external connections according to the following instruction. Check connections after wiring to 
make sure all connections are correct. (Do not use the control circuit buzzer to check connections) 
(A) Main circuit’s wiring must be separated from other high voltage or high current power line to avoid 
noise interference. Refer to the figures below: 
 
 
z  A noise filter in the output of the main circuit can suppress conducted noise.  
z  To prevent radiated noise, the wires should be put in a metal pipe and distance from signal 
lines of other control equipment should be more than 30 cm. 
 
 
 
 
 
 
 
Power Supply 
MCCB 
o
se  
Filter
 
 
Metal Box 
Metal Pipe 
Signal Wire
Controller 
above 
N310
Noise  
Filter 
Figure 3-4a) Installation Examples 
Figure 3-4b) Installation Examples using a filter and Isolation transformer 
Figure 3-4c) Installation Examples with Adjacent Signal Conductors