Question on Dedicated Space for panelboards in Conference Room

Status
Not open for further replies.
Hi there,

First time posting, long time lurker. I recently started a new job a few months ago as the facilites electrician for moderate sized machine shop. Over the past few months, I've been working my way through the plant fixing up any code deficiences or electrical issues I have come across.

My question concerns dedicated space in regards to panelboards in the facility's main conference room.

Sometime in the years before I started working here the company converted several machining areas into one large conference room (~40' x 80')- they left all of the existing panels and enclosures in place, however, with no clear warning designations or dedicated space indication (other than a few old "stay clear 3ft" stickers slapped on the panel covers). All of the electrical equipment in question is located in a corner of the room (mostly 480v) and along the adjacent wall (mostly 120/208V). The 480V equipment is directly in line with the entrance to the room, along the perpendicular wall facing the door. There are no barriers preventing people from coming within acceptable clearance areas in front of the equipment. All of the smaller 120V stuff already violates NEC 110.26(A)(1) because it is enclosed in cabinets which are so close to the front of the panels the doors cannot even be opened more than a 1/4 of the way, and nearly impossible to reach the panel screws to take the cover off (this issue has already been addressed). Corporate will also be having an arc flash study done this year (to comply with new labelling and incident zone requirements).

My question is in regards to the larger-sized equipment located in the room (by larger I mostly mean 480v).

First off, the room is being used as a large conference room, with frequently 100+ people gathering in it. Currently, there is talk from management of converting the room into office space by installing 40 cubicles. I've checked NEC Article 518 [Assembly Occupancies] and NEC 110.26 [Working Clearance] and could not find the answers I was hoping to get.

The question I have is in regard to the following equipment: (1) 120/208Y Panel, (1) 277/480Y Panel, (1) 277/480Y Distribution Panel, (1) 75kVa 480 to 120/208 Floor Mount Transformer. Now, according to NEC 110.26, the equipment has proper working clearances, as far as width, height, and depth goes (the room is pretty much open). The issue I have is with the definition of "dedicated equipment space" and general safety for unqualified people. According to NEC 110.26(F), dedicated equipment space reads as, "All switchboards, panelboards, distribution boards, and motor control centers shall be located in dedicated spaces and protected from damage." - does this mean the company will have to enclose all of the equipment in a dedicated "electric room" with access by qualified personell only by building walls and having a lockable egress? Or will simply cautioning off the area with means such as balusters/tape/chain, etc suffice? As of right now, the equipment is right out in the open in clear view with no precautionary measures. Are any of these required spaces affected by NFPA Arc Flash requirements? I hope I am correct in the assumption that the area in question will have to be walled off from the general populace, as just from looking at it, it seems to be unsafe. I have to back up my claims with concrete evidence to management though, and prove that it is a code/safety violation. I can provide images of the equipment if necessary.

Any help or guidence that you guys could lend me would be greatly appreciated.

Thanks again!
 

charlie b

Moderator
Staff member
Location
Lockport, IL
Occupation
Retired Electrical Engineer
All of the smaller 120V stuff already violates NEC 110.26(A)(1) because it is enclosed in cabinets which are so close to the front of the panels the doors cannot even be opened more than a 1/4 of the way, and nearly impossible to reach the panel screws to take the cover off (this issue has already been addressed).
This part I cannot visualize. A sketch or photo would help. But the rest of your concerns are non-issues, in my opinion. As long as they maintain the required working spaces clear of any obstacles, there is no reason they can't use the room as a conference area or an open office area. The fact that people can walk in front of the panel (i.e., walk into the working space) is not a problem. If a person is actually working on a panel, then the area should be cordoned off, to keep people from interfering with the work.

As to your questions about the ?dedicated space,? that is not referring to the room in which the panels are located. That is all about the space directly above and directly below the panel itself. You can?t, for example, run a pipe over a panel, unless the pipe is at least 6 feet above the top of the panel and there is a drip shield in place.
 

Carultch

Senior Member
Location
Massachusetts
Dedicated space is unrelated to the occupancy of the room. It doesn't require that you keep the equipment in a locked utility room where only electricians go. Few, if any rules require that.

Dedicated space means that for equipment requiring it, you cannot put any foreign systems within the FOOTPRINT of that space, either above or below. The dedicated space extends all the way down to the structural floor or grade, and it extends up either 6 ft above the top of the equipment, or up to the structural ceiling. This doesn't mean that you need a dedicated room for your electrical work. It just means that you need dedicated space based on the physical size of the electrical equipment.

Foreign systems would be systems such as plumbing, gas, HVAC and ductwork. Systems that other trades build, who do not work with electricity, and can present a hazard to your equipment. You cannot place their equipment or their piping/ductwork in the dedicated space of your equipment.

Dedicated space is dedicated to all electrical work. You can have conduits from other unrelated electrical systems, pass through the dedicated space of your equipment. The space is dedicated to the electrical installation.

A gray area on this rule that you might anticipate is communication/data systems. Do these count as "foreign to the electrical installation", or do these count as part of the electrical installation? Most communication/data systems work with electricity and are covered by the NEC. Fiber optics are non-electrical, but still covered in the NEC. Since the people installing the DATCOM systems are likely also familiar with the NEC, and there is seldom a hazard to your equipment because of theirs, I would see it as part of the electrical installation.
 
Thanks for the replies!

My main concern was having such large panels unprotected so close to all of their workers. Like I said, I couldn't find anything that said it wasn't acceptable, but I really wanted to double check before the went forward in moving all of their cubicles into the room.
And thanks for the clarification of "dedicated space" - while I knew that it referred to the immediate surroundings of the energized equipment, I wasn't sure if there was something else about the definition that I was missing regarding having unqualified persons so close to the panels.
Thanks again!

@ charlie b:

I might be able to describe the area I was talking about a little better - as I mentioned before the area was once a machining area - the wall in question was just a bare wall - it has alarm system panels, lighting control panels, timeclocks, security panels, a few troughs, and (4) 120v panels. When they converted the room into a conference room, someone had the idea to box in all of this electrical equipment (for aesthetic purposes) in makeshift cabinets. I can only assume it was a regular maintenance guy just doing his job. The walls of these "cabinets", however, only come off the panels about 6 inches, and in several spots the way the doors on the cabinets are layed out, it prevents the door of the panel to open 90 degrees (110.26) or to even access the screws to open the covers.

I have included a picture I took of it the other day - note panel P-1 cannot be opened. Panel P-2 is fine; The panel below it the cover is falling off; The screws on the trough are inaccessable; et al.

IMG_20150212_080605.jpg
 

Attachments

  • IMG_20150212_080605.jpg
    IMG_20150212_080605.jpg
    128.8 KB · Views: 4

augie47

Moderator
Staff member
Location
Tennessee
Occupation
State Electrical Inspector (Retired)
That would constitute a violation. The equipment move have the 110.26 prescribed working space to the designated depth (36"-48" depending on factors)
The minimum space required would be 30" wide and 36" deep with no obstructions.

(Note that the 110.26 requirements are for equipment "likely to be worked on or examined while energized" and in most cases enclosed transformers are not included in that list)
 

charlie b

Moderator
Staff member
Location
Lockport, IL
Occupation
Retired Electrical Engineer
Let me add that the working clearance starts at the face of the panel. You can't have the front of the panel recessed any deeper than the front of the cabinet. The best way I have heard it described (by someone on this forum, I think, but I do not recall who) is that you have to be able to take the empty cardboard box that held your new refrigerator, and slide it in front of the panel. It has to be able to touch the face of the panel, and not bump into anything as you are sliding it into place. I like this method of describing what the working space needs to be.

The cabinet most definitely creates a code violation, and needs to be rebuilt. I would have them install floor-to-ceiling doors that, when open, give you access to all the panels.
 
Last edited:
Status
Not open for further replies.
Top