24" clearance to give room for person throwing disconnect.

[Chev]

We have been told that there is a required clearance of 24" to the side of an electrical enclosure that must be allowed for someone to stand while throwing a disconnect. We work primarily with 3 phase 480 volts. I saw another post from a few years back but all that was addressed was the clearance in front (42") and above (6'6") plus the standard width (30"). I can't find it and Mr. Google was no help, so here I am!

 

[S'mise]

Working space was 110.26(f) in the past code, but that should get you close.
Usually 3ft working clearance in front of panel and 6 1/2 ft vertically.

 

[iceworm]

We have been told that there is a required clearance of 24" to the side of an electrical enclosure that must be allowed for someone to stand while throwing a disconnect. ...

Nope. As S' said, 110.26.A .
Width of working space, as wide as the equipment, min 30" - for equipment ... "likely to require examination, adjustment, servicing, or maintenance while energized".

Non-fused disconnects (maintenance safety switch for example) often are not required to even have that. For example, HVAC motors tucked up in the overhead often have a disconnect switch right next to them and all you can see of the switch is the front. 110.26.A.4 Limited access is new this cycle, but doesn't change anything for non-fused safety switches.

That being said, all the electricians I've been around have been taught to stand to the side when opening current breaking contacts. Some will get pretty vocal if there isn't space to stand off to the side. If this is something that might be opened under *significant load*, I agree.

Definition: *significant load*:
A 3hp, 208V, 3ph, motor is not
A 100hp, 480V, 3ph is.
Everything in between - subject to interpretation;

 

[charlie b]

We have been told that there is a required clearance of 24" to the side of an electrical enclosure that must be allowed for someone to stand while throwing a disconnect.

It's not in the NEC. Whether OSHA has something to say on the subject is beyond my knowledge. So my inclination is to offer two questions to you: (1) Who told you this, and (2) What would that person give you as the source of this "requirement"?

 

[charlie b]

I will add that I was once a participant in a review of a switchboard failure incident. We were tasked with determining the cause and extent of damage and the likelihood that repairs could be possible. One of the maintenance crew was present in the room when it happened. He was talking over a radio to a person in another part of the building, and gave the instruction for the other person to energize the board. But he moved to the side of the board before he gave that instruction. That is why he lived to tell the tale. The board exploded, throwing the panel cover across the room and sending molten metal everywhere. He was, very fortunately, far enough to the side to avoid any injury. But he was still shaken by the incident several days later, when I spoke with him.

 

[sameguy]

480v is a 10' danger taped off no entry without ppe and proper need.