7.2.3Attaching surge killers to control equipment

If communication errors happen in synch with the on/off signals from certain control equipment (referred to as "load" hereafter) such as no fuse breakers, electromagnetic contactors, relays, solenoid valves, and induction motors, surge noise interference is suspected.

If this problem happens, keep the ground cable and communication cable away from the load. If that is not possible, an installation of a surge killer will help reduce noise interference. Place the surge killer as close to the load as possible.

Remedy for AC inductive load

Keep the ground cable and communication cable away

 

 

from each other.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Output

 

 

 

 

C

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

L:Load

 

 

 

 

 

 

R

 

 

 

 

AC

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Place the surge killer near the load.

 

 

Output equipment

 

 

 

 

 

 

such as PLC output unit

 

 

 

 

 

 

Remedy for DC inductive load

Keep the ground cable and communication cable away

 

 

from each other.

 

 

 

 

 

L:Load

 

Output

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

D

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

DC

 

 

 

 

Place the surge killer near the load.

 

 

 

 

Output equipment

 

 

 

 

 

 

such as PLC output unit

 

 

 

 

 

 

7 - 6

7. WIRING

 

7.2 Wiring inside and outside the panel