Metal Enclosed Switchgear Vs. Arc Flash
Metal Enclosed Switchgear Vs. Arc Flash
(OP)
We have specified a metal enclosed switchgear built as per ANSI C37.20.1. An arc flash reduction system (ARMS) was specified (Eaton make) to reduce the arc flash. With ARMS activated at the incomer circuit breaker, the arc flash is substantially reduced at the switchgear bus side. The line side arc flash is still high though.
My concern is that, does the metal enclosed construction have adequate segregation between the switchgear bus side from the line side such that the line side arc flash will not propagate to the bus side?
Are the barriers between the incoming cable compartment and the bus sufficient? I appreciate any experience for this. Thanks.
My concern is that, does the metal enclosed construction have adequate segregation between the switchgear bus side from the line side such that the line side arc flash will not propagate to the bus side?
Are the barriers between the incoming cable compartment and the bus sufficient? I appreciate any experience for this. Thanks.






RE: Metal Enclosed Switchgear Vs. Arc Flash
RE: Metal Enclosed Switchgear Vs. Arc Flash
Rafiq Bulsara
http://www.srengineersct.com
RE: Metal Enclosed Switchgear Vs. Arc Flash
RE: Metal Enclosed Switchgear Vs. Arc Flash
Will insulating the bus in addition helps?
RE: Metal Enclosed Switchgear Vs. Arc Flash
Is this ANSI rated switchgear? There are ANSI standards for arc-rated switchgear.
Insulating the bus reduces the risk of arcing faults, but the potential hazard does not change. The worst-case of a three-phase arcing fault is always a possibility.
RE: Metal Enclosed Switchgear Vs. Arc Flash
Some of the 'squabbling' I mentioned relates to some manufacturers using fully insulated bars are able to claim that their gear is arc-proof by virtue of it being 'impossible' to strike an arc because the IEC test procedure doesn't allow insulation to be damaged in order to initiate the arc. I think certain manufacturers are playing cute games with the wording of the IEC document and as it stands the document essentially allows non-arc-rated boards to masquerade as arc-proof.
Maybe it is 'impossible' to strike an arc; I seem to remember that it was 'impossible' for a very famous liner to sink to the bottom of the North Atlantic too...
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RE: Metal Enclosed Switchgear Vs. Arc Flash
In this case, the ARMS will not be that useful except for bus faults only.