Switchgear Ground 1

[tulum]

Hello,


I have two pieces of switchgear (same man.);

(1) The ground bus is mounted on metal angles spaced every couple of feet (cont. throughout unit).

(2) The ground bus on the next unit is bolted flat to the enclosure wall (cont. throughout unit).

Are there any electrical issues with laying groundbus directly on enclosure like this?

Regards,
TULUM

 

[mpparent]

As far as I know, the Ground bus is always in direct contact with the enclosure for typical electrical equipment (except for an isolated ground).

Mike

 

[tulum]

mpparent,

I guess my question came from the fact that in a control house (switchgear inside a building) there is a standard in the mines to provide a ground bus inside that is mounted on 600v insulators.

What is the advantage of this? All the switchgear circuits are tied to this bus, however the switchgear circuits are also bonded to the building...

My only thoughts on both of these scenarios is the fact that theoretically the may produce a less resistive path fro ground current making it easier to monitor and keep at a safe potential.

Shots in the dark...


Regards,
TULUM

 

[RalphChristie]

Tulum,

What kind of switchgear? Metalclad? Seems the intention was a very simple form of busbar earth-fault protection - by lightly insulating from earth all metal framework. The framework is connected to earth at only one point and a CT connected over this connection.

See:

http://www.areva-td.com/servlet/Con...d=1017999014820&tab=Chapters&id=1056536208254

Download Chapter 15 (Busbar protection) pg 236 (Ch 15.6)