Clearance from Disconnecting means?

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scrublink

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A contractor installed a 60 Amp, 600 volt Disconnect in one of our mechanical rooms. He installed it about 2 inches in from the door frame. This is not behind the door. Several years back an inspector made me move a disconnect that was 6 inches from a door frame in a similar situation. That was a large job and the inspector was someone I had worked with so I moved it without questioning him. Before I talked to the contractor on this occasion I sat down with the "good" book and looked for some guidance. Couldn't find anything that would prohibit this switch from its present location. Any thoughts or input on this matter.

Specifics: 480 Volts, in a mechanical room with limited access. All other code issues have been complied with at this point.

Thank you in advance for you input.



Ed
 
As far as I know if the requirements in 110.26 are met then you would have a compliant installation with respect to working clearances.

Pete
 
The rules for working clearance require at least 30 inches side to side, and at least 36 inches away from the panel (possibly more), to remain clear. There is no rule that says a panel can?t be immediately next to a door frame. Your previous experience with the Inspector was an unfortunate example of an authority imposing his own will, and not limiting his inspection to the requirements in the code.
 
So I guess the door's swing doesn't have to be taken into consideration. That was my thinking. If the door is open or closed the installation is in compliance. When it is opening or closing it is not in compliance. I actually can see it as going either way, and that is always troubling. Black and white is better than shades of gray.



Ed
 
scrublink said:
If the door is open or closed the installation is in compliance. When it is opening or closing it is not in compliance.
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Not true at all.

You said the panel is not behind the door. So the door is hinged on the side opposite to the panel. The point on the door that is farthest from the hinge is the latch (or whatever it is called) that holds the door closed (keeps it from being pushed open by a passing breeze). The panel is farther from the hinge than that latch.

The hinge itself is the center of a circle that is described by the latch, as the door swings open. That circle never passes in front of the panel; the door never swings into the working clearance space. It can’t. The radius of the circle is shorter than the distance to the panel, no matter what position the door is in. Draw a picture on a sheet of paper, including the circle made by the swinging door and the working space, and you will see what I mean.
 
The way I am thinking about this is: There is no object in the way (within 30 inches) when the door is open or closed just when it is ajar. This would lead me to believe that this is in compliance.
 
scrublink said:
There is no object in the way (within 30 inches) when the door is open or closed just when it is ajar.
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You missed my point. There is no object in the way when the door is ajar either. A door ajar would not be within that 30 inch area. So yes, it is in compliance, regardless of the state of the door.
 
I can't seem to find to door jam requirement:
Table 110.26(A)(1) Working Spaces
Nominal Voltage to Ground
Minimum Clear Distance
Condition 1
Condition 2
Condition 3
0?150
900 mm (3 ft)
900 mm (3 ft)
900 mm (3 ft)
151?600
900 mm (3 ft)
1.1 m (31/2)
1.2 m (4 ft)
Note: Where the conditions are as follows:
Condition 1 ? Exposed live parts on one side of the working space and no live or grounded parts on the other side of the working space, or exposed live parts on both sides of the working space that are effectively guarded by insulating materials.
Condition 2 ? Exposed live parts on one side of the working space and grounded parts on the other side of the working space. Concrete, brick, or tile walls shall be considered as grounded.
Condition 3 ? Exposed live parts on both sides of the working space.
(2) Width of Working Space The width of the working space in front of the electric equipment shall be the width of the equipment or 750 mm (30 in.), whichever is greater. In all cases, the work space shall permit at least a 90 degree opening of equipment doors or hinged panels.
 
So, what you are telling me is that if I held a stick thirty inches from the disconnect that when I opened the door the stick would not be in the way. There is no way around the fact that 30 inches to the side of this disconnect is 28 inches into the door swing. I can't see it as being a real life issue, but I can see where an inspector might wish to argue about it.



Ed
 
The 30 inches can be measured from the center, either edge or any where in between. In other words, you could have 1" on the left side 11" across the disconnect itself and 18" to the right for a total of 30 inches, or any combination that would give you 30 inches of space when you are standing in front of this disconnect.

Roger
 
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And, the 30" width is only required when "working" on the device. If the door can be "blocked" open or shut then its location is a non factor.
 
OK. Now I see where we are not communicating successfully. I had been thinking that the required 30 inches of side-to-side clear space started at the door jamb, and went from that point away from the door. You had been thinking that the 30 inches began at the side of the panel, and went from that point into the direction of the door.

Look at Roger's comment, and tell me what you think now.
 
I think the measurement starts at the edge of the equipment away from the possible obstruction, across the equipment, and toward the possible obstruction.

This comes in handy when two pieces of equipment can share the majority of a single space; from the left edge of the left piece to the right edge of the right piece.
 
jim dungar said:
And, the 30" width is only required when "working" on the device. If the door can be "blocked" open or shut then its location is a non factor.
Click to expand...


I'm with Jim. The switch could be 2" from the edge of the door with a wall adjacent to the opposite side of the switch and still be code compliant.
 
Unless I'm mistaken, you can mount equipment behind a door as well. I personally don't see a problem with that. Just provide a door stop so the door doesn't bang into the equipment. Generally that's where I put the computer or telephone back boards. Note, the door is generally over 6 inches off the wall I'm using.

RC
 
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