Electrical Working Space

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dcheser

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If I have an Electrical Room with Two MCC's Face to Face both rated 800 amps. I have a working distance of 4' between them. I also have an aisle way per say around the ends of the equipment. The width of this aisle way is 30" on either end between the MCC and the wall. Is 30" sufficient or by code does this need to be larger say 36". If you can please site where I can find this in the code.
 

charlie b

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Lockport, IL
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The working space rule only applies to the portion(s) of the MCCs that can have the covers removed, so that a worker has access to the internals. If you can't get access from the sides, then you don't need working clearance on the sides.
 

dicklaxt

Senior Member
I don't recall for sure but I think OSHA means of egress minimum is 27" and there must be two excape paths. If those are good numbers then I think you got it covered.

dick
 

dcheser

Member
Thanks for the reply Charlie!! So 30 inches along the side is sufficient there is nothing in the code that dictates this? I am laying out the equipment and sizing the room and recieved a comment that a minimum of 36 inches is required. I can't find anything in the code book to support or dispute this.
 

charlie b

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Lockport, IL
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Let's be clear: Working space is one thing. Egress is another thing. I don't have a complete mental picture of your layout, and in particular I don't know where the door(s) might be. NEC article 110.26 tells us that you need 4 feet between the MCCs (presuming they are 480 volts or lower). You have that. I don't think I have seen an MCC with side-access panels, so I can't imagine needing working space on the sides. You would have to tell us if that were not the case. But as to making your way to the exit door(s), I do not know where to find the rules that give minimum widths of the pathways.
 

dicklaxt

Senior Member
I found this on the net and there are lots of rules to establish dimensions,the following is in general shall be,,,but I think if it is an emergency path around equipment is something less............probably ought to be what ever it takes to get yourself free from harm,,,,,,,,,,I made a copy for info only.

Osha 1910.37 Means of egress, general (f) Access to exits. (6) The minimum width of any way of exit access shall in no case be less than 28 inches. Where a single way of exit access leads to an exit, its capacity in terms of width shall be at least equal to the required capacity of the exit to which it leads. Where more than one way of exit access leads to an exit, each shall have a width adequate for the number of persons it must accommodate.


dick
 

dcheser

Member
Dick thanks for the info!!! I also did some additional digging and found the following:

The only reference the NEC makes to this is in regard to working space. Working space is required around electrical equipment that has or can have exposed live parts. Since the side of the MCC has nor will have no exposed live parts the Working Space does not apply. Referring to the International Building Code
Chapter 10 MEANS OF EGRESS 1017.2 Corridor Width - The minimum corridor width shall be as determined in section 1005.1, but not less than 44 inches (1118mm)
Exceprions:
1. Twenty Four inches (610mm) - for access to and utilization of electrical, mechanical or plumbing systems or equipment.
 
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