Vented Panels on 4160VAC Switchgear

[buffalonymann]

My facility installed new 4160VAC switchgear about 16 months ago; the enclosure rear access panels are vented. I can't remember ever seeing vented access panels on medium voltage gear. Anybody care to comment?

 

[Jraef]

Depends on what's inside. High amperage bus bars often need ventilation.

 

[ron]

Not unusual.

Unless the equipment is listed as arc resistant and tested per IEEE C37.20.7[FONT=Arial, Arial, sans-serif] (which yours is not with vented panels in the rear), the doors should always be considered to be shrapnel during a fault.[/FONT]

 

[Tony S]

Once you see the aftermath of a MV flashover you’ll realise why they vent to the back. We had a 50 year old 11kV OCB flashover. Had anyone been at the front they would have been dead. The switchroom looked like a bomb had gone off, the shrapnel had to be chiselled out of the brickwork.

Even LV gear can be a death trap. A fire on one of our plants forced me open a dependant manual switch on load. I’d been taught the “left hand rule” never stand directly in front of a switch. The cast iron front blew out, I was just slightly singed.

 

[Jraef]

This video gives a pretty good idea of the risks involved. If you keep watching, they show it in SlowMo