Clearance

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Tim Ganz

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What are the clearance rules for cabinets and panel boards. I know control cabinets need 3 foot clearnce on the fron but what about top and sides? Is it 3 foot on the sides? I see a lot of them mounted almost touching each other.
 
Tim Ganz said:
What are the clearance rules for cabinets and panel boards. I know control cabinets need 3 foot clearnce on the fron but what about top and sides? Is it 3 foot on the sides? I see a lot of them mounted almost touching each other.
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Take a look at 110.26 (F)(1) Dedicated Equipment Space several exceptions depending on ceiling height , drop ceiling etc. 6 foot zone above
 
These graphics from the NECH may help:

Working space:

workingspace.jpg



Dedicated equipment space:

Dedicatedspace.jpg
 
Why only 6'6" for working space?

Why only 6'6" for working space?

Why do they only allow 6'6" for working space? Let's say the top of a panel is 7' AFF and the panel extends 6" off of the wall. What prevents a tinner from running his 4 foot wide duct work at 6"7" AFF and 6 1/4" off of the wall right across the panel? He is above the working space and outside of the equipment space so I'd say he's compliant. Or am I looking at this wrong.
 
Tim Ganz said:
What are the clearance rules for cabinets and panel boards. I know control cabinets need 3 foot clearnce on the fron but what about top and sides? Is it 3 foot on the sides? I see a lot of them mounted almost touching each other.
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I agree that all the information you need is in the attachments and code sections others mention, but to your specific question, pieces of equipment can share the same working space. There are explanations about how far out associated equipment can extend above and below the equipment, but interestingly the same provision doesn't appear to apply to the sides. Perhaps we should propose a revision of this section to allow this. Anyway, two panels of the same depth can be mounted side by side and share the same working space, and I doubt most AHJ's would write up an installation where there was a small variance in the depths even though they could.
 
Tim Ganz said:
What are the clearance rules for cabinets and panel boards. I know control cabinets need 3 foot clearnce on the fron but what about top and sides? Is it 3 foot on the sides? I see a lot of them mounted almost touching each other.
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Generally speaking there is no requirement for side clearances unless the the specific equipment needs side access as in the case of some large switchboards or what have you.

Here is a pretty common installation.

CR-EQsystems.JPG


Roger
 
Microwatt said:
Why do they only allow 6'6" for working space? Let's say the top of a panel is 7' AFF and the panel extends 6" off of the wall. What prevents a tinner from running his 4 foot wide duct work at 6"7" AFF and 6 1/4" off of the wall right across the panel? He is above the working space and outside of the equipment space so I'd say he's compliant. Or am I looking at this wrong.
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You are missing the last sentence of 110.26(E). They reserve a minimum of 6'-6" in order to allow most of us (not all, I admit) to stand up straight while standing in front of the panel. It is a headroom clearance space, as the title of 110.26(E) suggests. But if the top of the equipment is higher off the floor than 6'-6", then the working space extends to the height of the top of the equipment.
 
Strathead said:
There are explanations about how far out associated equipment can extend above and below the equipment, but interestingly the same provision doesn't appear to apply to the sides.
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I never noticed that before. Wow, learning something new on a Friday, and even before my second cup of coffee. Thanks, Strat. :)

I have always avoided putting a 6 inch deep, 22 inch wide panel directly in between a pair of 9 inch deep panels, out of concern for the working clearance of the smaller panel. But I had not thought of it in terms of the 6 inch allowance for equipment above or below a panel. So I suppose you could describe that habit of mine as being, “accidental compliance.” :lol:
 
charlie b said:
You are missing the last sentence of 110.26(E). They reserve a minimum of 6'-6" in order to allow most of us (not all, I admit) to stand up straight while standing in front of the panel. It is a headroom clearance space, as the title of 110.26(E) suggests. But if the top of the equipment is higher off the floor than 6'-6", then the working space extends to the height of the top of the equipment.
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Thanks Charlie. You are right I did miss that part. OK lets say the duct work was brought up to the height of the top of the panel, 7'. It still would be very difficult for one of us to add conduits to that panel.

I'm actually currently dealing with this situation right now. I have someone who wants to run cable tray over a panel. He say's he heard it only needs to be 6'-7" off of the floor. I told him if it's above the panel it needs to be 6' above it and directed him to the NECH. I can see him now wanting to just move the tray out from the wall 6" in order to drop it down to the 6'-7" that he is looking for. If the top of the panel is at 6'-7" I dont see a violation but now I have to hang over his tray if I ever need to add a conduit. It just seems we are selling ourselves short on working space. We still have to work at heights greater than that of the equipment.
 
I feel your pain, Microwatt. Your description is correct. That would be a compliant installation, but a difficult one to work around in the future.
 
Tim Ganz said:
So I was wrong on the side clearnance but the 3 foot clearance from the front of the panel is still correct right?
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Could even be more in some conditions, see Table 110.26(A)(1) and the three conditions below it.

Roger
 
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