Equipment In Front of Arc Rated Switchgear

[ThePunisher]

Hi all, I have a technical query that would require some of your experienced thoughts.

WE have an arc rated MV and LV switchgear provided with arc flash ducting that diverts the arc energy outside the building walls. It was customary in previous designs that we do not place any equipment (panelboards, battery chargers, IT cabinets, etc.)in front of these arc rated switchgear.

However, it occurs to me, that the switchgear is already having mechanical arc mitigation by itself and we should be able to locate certain electrical equipment in front of it. Of course, personnel must still wear the appropriate PPE labeled on the switchgear.

Can we locate small electrical equipment on front of arc rated switchgear and comply only with working clearance requirements? I would think, our reliability folks would argue with me...however, arc flash protection is for personnel safety and not for equipment. Since, the switchgear is already arc rated with proper mechanical strength and energy venting, I would think it will not be an issue placing an equipment on front of it.

regards,

 

[wayne440]

You may get strenuous objection from site personnel if the proposed equipment is to be located in a potential (or perceived) escape route regardless of the PPE requirement.

 

[jraef]

The entire purpose of buying Arc Resistant gear is to facilitate exactly what you are wanting to do. That's why you paid the big bucks for it. Otherwise you could have just restricted access to qualified workers with the proper PPE.

If your gear is truly certified as Arc Resistant per ANSI C37.20, you should be in the "No PPE required" category to just be in front of it, as long as all the doors are closed, there are no known defects, it has been properly installed and maintained per the mfrs instructions.


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