What exactly are the allowable clearance distances for bus plugs. On our 2000 amp bus the plugs can be installed top or bottom mounted. In parts of our plant, if top mounted, you would not have 42 inches of clear space. (The ceiling would be within that distance). Also, on our 400 amp and 600 amp bus we have clearance problems because of the way they were installed 45 years ago. Almost all of the bus has one side facing the truss in the ceiling, or has other obstructions within the 42 inch limit, like fire sprinkler systems or old steam lines. These bus plugs are not items that get serviced or require much maintenance while hot, so do they have to have the clearances that floor mounted panels would need. Thanks in advance.
Bus plug safety
- Thread starter jbivens
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Re: Bus plug safety
I believe the depth of the working space from table 110.26(A)(1) is intended to include a "step back distance". (If an arc occurs or if the electrician gets shocked, he/she can step back from the panel without running into a wall or another panel.) So having 42" above a disconnect doesn't seem to be the intent of the code. In addition, I'm not sure what good a step back distance does for anyone standing on a ladder.
On the other hand, the disconnects still need to meet the first sentance of 110.26. "Sufficient access and wroking space shall be provided and maintained about all electric equipment..." Notice that this part doesn't say anything about having to work on equipment that is hot. It also doesn't say the distances in table 110.26(A)(1) have to be met.
Steve
I believe the depth of the working space from table 110.26(A)(1) is intended to include a "step back distance". (If an arc occurs or if the electrician gets shocked, he/she can step back from the panel without running into a wall or another panel.) So having 42" above a disconnect doesn't seem to be the intent of the code. In addition, I'm not sure what good a step back distance does for anyone standing on a ladder.
On the other hand, the disconnects still need to meet the first sentance of 110.26. "Sufficient access and wroking space shall be provided and maintained about all electric equipment..." Notice that this part doesn't say anything about having to work on equipment that is hot. It also doesn't say the distances in table 110.26(A)(1) have to be met.
Steve
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