SWITCHING OVERVOLTAGE IN 30KV AND 6KV SWITCHGEAR

[Parkpower]

Hi gentlemen,

Are surge arrestors needed to protect incoming cubicles and transformer or large motor feeder cubicles from switching overvoltage?

IF vacuum breakers are used,ABB 30kV and 6kV switchgear always install surge arrestors. But sometimes Siemens and Schneider do not install the surge arrestors.

Is there any IEC or IEEE code requirement concerning surge arrestors in switchgear?


Thanks,


Parkpower

 

[rbulsara]

Good companies observe good practices! Cheap ones seek excuses to become competitive.

SA at vacuum breakers are generally intended for taking care of overvoltages due to switching and it is a good practice. It is also a relatively inexpensive protection for unwanted surges coming from outside for any reason.


Rafiq Bulsara

http://www.srengineersct.com

 

[odlanor]

IEEE std 1313.1 – IEEE Standard for insulation Coordination – Definitions, Principles and Rules – 1996 (R2002):
switching overvoltage standard are applied only to system with maximum voltage > 242kV.