480V SwGr access

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Jerry Romero

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We have a prefabricated electrical building. Inside is a 480V piece of switch gear which is situated with the back against a wall. The Engineer of record says we need to have doors or removeable building panels, in order to access the rear of the switch gear for service reasons. Is there a section in the code where this is illustrated?


Regards,
 

charlie b

Moderator
Staff member
Location
Lockport, IL
Occupation
Retired Electrical Engineer
I disagree with the engineer of record, if that person is saying that rear access is always necessary, or that the NEC requires it. It is up to the manufacturer of the equipment to say whether rear access is necessary. That will depend on the make and model of the gear.
 

GeorgeB

ElectroHydraulics engineer (retired)
Location
Greenville SC
Occupation
Retired
Jerry Romero said:
We have a prefabricated electrical building. Inside is a 480V piece of switch gear which is situated with the back against a wall. The Engineer of record says we need to have doors or removeable building panels, in order to access the rear of the switch gear for service reasons. Is there a section in the code where this is illustrated?

Regards,
I've worked in many an electrical room with back-to-back MCCs; I'm with the suggestion to see what the manufacturer specifies. If back-to-back are forbidden, there will be a major rethinking in design houses.
 

Ragin Cajun

Senior Member
Location
Upstate S.C.
Are we talking about a MCC or 480V switchGEAR. BIG difference.

All the switchGEAR I have worked with required rear access to make cable connections. I have one job where the prefab building has exterior, NEMA 3R doors behind the switchgear for rear access.


Then again, you never really know . . .

Check with the manufacturer.

RC
 

masterelect1

Senior Member
Location
Baltimore
Jerry Romero said:
We have a prefabricated electrical building. Inside is a 480V piece of switch gear which is situated with the back against a wall. The Engineer of record says we need to have doors or removeable building panels, in order to access the rear of the switch gear for service reasons. Is there a section in the code where this is illustrated?


Regards,

There are requirements under Art. 110 which talk of headroom, clear working space in front of equipment. illumination levels, number of entrances/exits etc.. I find no "shall" re: back accessibility of gear. Actually, if you look at the NEC 2005 handbook, pages 49,50 & 51, exhibits 110.14,15,18,&19 there are illustrations which depict switchboards against the wall with no obvious rear access.
 

ed downey

Senior Member
Location
Missouri
If this is Swithgear (UL 1558) you will need rear access.

If this is a Switchboard (UL 891) you will most likely not need rear accessibility.

you should definitely check with the manufacturer.

-Ed
 
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