Confused...30x36 space for new main breaker panel

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  #1  
Old 08-26-12, 08:58 PM
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Question Confused...30x36 space for new main breaker panel

Hello to all, this is my first of many post. I'm currently installing a breaker panel inside a new basement addition. I've already installed the meter with main switch outside.

I'm confused about the code requirement that states you need a 30x36 unobstructed space around the breaker panel. My question is does the 30x36 space include the space occupied by the breaker panel. Or do I to have 36" above the top of the panel and 36" below the bottom of panel. And 30" from each side of the breaker panel. The attached photos show where I plan on putting the panel.
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Another question... The ground I plan on using is "rebar" placed in the concrete wall. The rebar is attached to the rebar in the footing. Is this the only ground I need or do I need to use a rod in the ground. I have no metal gas or water pipes. See attached pic.
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I look forward to your comments.
Dan
 
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  #2  
Old 08-26-12, 09:57 PM
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Thirty six inches in front of the panel and thirty inches side to side. It does not need to be centered in the thirty inch side to side space. The analogy often use is if you can put a refrigerator box in front of it you have enough space. Maximum height of the top breaker is six feet seven inches.
 
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Old 08-27-12, 05:09 AM
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The NEC allows your Ufer or CEE to be the only ground.
 
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Old 08-27-12, 08:32 AM
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My question is does the 30x36 space include the space occupied by the breaker panel. Or do I to have 36" above the top of the panel and 36" below the bottom of panel. And 30" from each side of the breaker panel.
The required clear space in front of the panel is a rectangular solid, 36" deep and 30" wide, extending from the floor to the ceiling. This space can be shifted side-to-side, so long as the entire panel is within the 30" width. Which leads me to a question:
The attached photos show where I plan on putting the panel.
The NEC requires that a panel be mounted vertically:
240.33 Vertical Position.
Enclosures for overcurrent devices shall be mounted in a vertical position unless that is shown to be impracticable. Circuit breaker enclosures shall be permitted to be installed horizontally where the circuit breaker is installed in accordance with 240.81. Listed busway plug-in units shall be permitted to be mounted in orientations corresponding to the busway mounting position.
and the 30" width assumes that the panel is mounted in a vertical position. Does your permit allow you to mount this panel horizontally? If so, the 30" width should be increased to equal the side-to-side measurement of the panel enclosure in this case.

Edit to add: Perhaps I misinterpreted something. Did you just lay your panel enclosure on top of the foundation to illustrate its location in the space, and you're planning to mount it vertically?
 

Last edited by Nashkat1; 08-27-12 at 09:16 AM.
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Old 08-27-12, 09:15 AM
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I don't think mounting that panel vertically is impractical to allow an exception to 240.33
 
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Old 08-27-12, 09:20 AM
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I don't think mounting that panel vertically is impractical to allow an exception to 240.33
I agree. If the distance AFF to the uppermost breaker is an issue, I'm imagining that the panel could be mounted in a purpose-built frame just in front of the exterior wall.
 
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Old 08-27-12, 10:14 AM
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I did plan on mounting it horizontally.
 
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Old 08-27-12, 10:18 AM
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I don't think your inspector will allow a horizontal panel. Why do you want it horizontal?
 
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Old 08-27-12, 10:22 AM
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I find it odd that almost every HoH show that works with the panel....it's horizontal 90% of the time it seems.

In this case...It looks like the panel is too tall for the area above the block? Could just be the pic. And that would put the main too high I would think?
 
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Old 08-27-12, 10:41 AM
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Horizontal mounting is allowed in Canada where many of the shows seem to originate.

If the area is not tall enough there are other code issues to deal with.

The other part of 240.33 to be concerned with is this part "Circuit breaker enclosures shall bepermitted to be installed horizontally where the circuit breaker
is installed in accordance with 240.81." which requires UP to be ON. Half of the panel could not be used for breakers if mounted horizontally.
 
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Old 08-27-12, 11:47 AM
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I did plan on mounting it horizontally.
Does your permit specifically allow that? You did pull a permit, didn't you?

Mounting that panel horizontally is not feasible. What do you think of mounting it vertically in front of the wall?
 
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Old 08-27-12, 12:29 PM
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Pcboss....ohh...that would be a deal breaker if they mean all breakers have to be up. I doubt they meant just the main.

And I think I've seen panels where the main is up/down when the rest are side to side? I could be remembering the Navy.

I bet right now Dano is going "Say what? I thought this was going to be simple!".
 
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Old 08-27-12, 12:56 PM
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Vic, most breakers operate towards the center is on. Now if the panel is turned one entire side of the panel has the breakers down and on. The top half of the panel is now unusable. All breakers need to be up = on. Mains now operate sideways to allow the main to be at the bottom.
 
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Old 08-27-12, 01:09 PM
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I think I've seen panels where the main is up/down when the rest are side to side?
Sure, that's the way most panels are built. As I read it, Section 240.81 requires that the main be UP ON and DOWN OFF. All the others can be, and usually are, side-to-side.

That said, somewhere in there, IIRC, it's disallowed to mount breakers so that they are the exact oposite of that - IOW, DOWN ON and UP OFF. That's why Pcboss is saying
Originally Posted by pcboss
Half of the panel could not be used for breakers if mounted horizontally.
I bet right now Dano is going "Say what? I thought this was going to be simple!".
Yeah, but it ain't all that hard either. Between talking with his inspectors during the permitting process and afterward, reading Wiring Simplified, and asking questions here, he should pull through OK.
 
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Old 08-27-12, 01:11 PM
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Mains now operate sideways to allow the main to be at the bottom.
Oops! Been awhile since I did a stand-alone panel, and I forgot about that!
 
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Old 08-27-12, 01:24 PM
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Oh....I understood what you meant about the breakers.
 
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Old 08-27-12, 01:29 PM
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Well...I've got one of the meter box/panel combination things mounted outside and the main is at the bottom, right in line with the branch breakers. When I first looked at it I thought I didn't have a main breaker...till I looked closely and saw "service disconnect" stamped in the cover.
 
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Old 08-27-12, 01:35 PM
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I've got one of the meter box/panel combination things mounted outside and the main is at the bottom, right in line with the branch breakers.
And all of the breakers toggle - let me guess - side-to-side, right?
 
  #19  
Old 08-27-12, 01:49 PM
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Sure thought I would have this done by 7 this morning then go fishing.

Okay...Plans B and C

Plan B. Hang the panel vertical attached to 3/4" plywood. Part of it will hang over the block wall. I will maintaine the 6'7" height as per code. One issue is a purposed 30" closet door under the stairs. It may overlap the panel when open.

Plan C. Install the panel between the studs that support the stairs, panel would face outward into the room. My conserns here is wiill this be within code. And it reduceses the number of holes to run wire out of the box to the top only. How many 12g wires can you leagly run thru one cutouts in the panel?

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Comments and suggestions are appircated,
dano
 
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Old 08-27-12, 02:15 PM
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Plan B. Hang the panel vertical attached to 3/4" plywood. Part of it will hang over the block wall. I will maintaine the 6'7" height as per code. One issue is a purposed 30" closet door under the stairs. It may overlap the panel when open.
So long as the door can be closed that is not a problem. I'd go with plan"B". Just a comment. The box does not have to be centered in the thirty inch space. While not necessary if you wanted you could move it closer to the right to give more clearance for the closet door but it is not required.
 
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Old 08-27-12, 02:16 PM
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And all of the breakers toggle - let me guess - side-to-side, right?
Well..yeah....but I'm pretty sure my house in VA had an up/down main.....might be wrong. Like I said...more time in the Navy panels then in any house stuff.

Dano....the open door thing doesn't matter as long as when closed you have the space requirements.

I've seen people build cabinets around panels and I think one even had a hinged picture.
 
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Old 08-27-12, 03:16 PM
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Sure thought I would have this done by 7 this morning then go fishing.


Plan B. Hang the panel vertical attached to 3/4" plywood. Part of it will hang over the block wall. I will maintaine the 6'7" height as per code. One issue is a purposed 30" closet door under the stairs. It may overlap the panel when open.
Sounds good. Either move the panel far enough to the right to be beyond the open door, or just don't worry about it. The panel could be entirely covered by the open door as long as you have the 30" x 36" space when the door is closed.

How are you planning to run the cables if you go with this plan? They have to be covered when you're done. See "Plan D" below.

Plan C. Install the panel between the studs that support the stairs, panel would face outward into the room. My conserns here is wiill this be within code. And it reduceses the number of holes to run wire out of the box to the top only. How many 12g wires can you leagly run thru one cutouts in the panel?
6 12AWG wires, but I think you're asking "How many 12-2/G or 12-3/G Type NM cables can you legally run thru each 1/2" knockout in the panel?" That answer is two 12-2/G cables or one 12-3/G cable, IIRC.

Why are you writing off the bottom of the panel for cable entry with this location? Why couldn't cables come down in the adjacent stud bays and loop up into the bottom of the panel? My concern with this location is that it will be difficult to feed from your meter and main breaker.

Plan D. Install the panel between a pair of studs framed up in front of the exterior wall. I'm imagining that that will put it close to the service entrance. With a careful design, you could bring branch circuit cables into both the top and bottom of the panel, and you could bring the service feeder cable into the top of the back. This could be finished out as a column with the panel visible, as a column with a recessed front for the panel and a hinged access, or as a cabinet with a recessed panel mount and one or two hinged doors.
 

Last edited by ray2047; 08-27-12 at 03:33 PM. Reason: Remove incorrect attribution.
  #23  
Old 08-27-12, 03:41 PM
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There should be plenty of knockouts in the top of the panel for the circuits. You cannot bring more than two cables into a knockout so don't plan on removing say the 2" KO and running a bunch of cables into the panel.
 
  #24  
Old 08-27-12, 05:31 PM
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Plan D. Install the panel between a pair of studs framed up in front of the exterior wall. I'm imagining that that will put it close to the service entrance. With a careful design, you could bring branch circuit cables into both the top and bottom of the panel, and you could bring the service feeder cable into the top of the back. This could be finished out as a column with the panel visible, as a column with a recessed front for the panel and a hinged access, or as a cabinet with a recessed panel mount and one or two hinged doors.
Plan D. I really don't want to put another panel on the exterior of the house. I already have a large combo meter/main breaker box mounted on the outside wall.

Why are you writing off the bottom of the panel for cable entry with this location? Why couldn't cables come down in the adjacent stud bays and loop up into the bottom of the panel? My concern with this location is that it will be difficult to feed from your meter and main breaker.
I like that idea of using the adjacent stud to run cable. In my case I don't think it would be difficult running the feed from the meter to the panel but it would be at least a 7' run. By placing the panel on the wall in the pic the run would be about 3'.

How are you planning to run the cables if you go with this plan? They have to be covered when you're done.
I planned on running the cables out the top and the sides to the ceiling of the basement and then to lights, plugs etc. Do they need to be covered as they leave the box? I've seen on the DYI shows where they come out of the box and into holes in the plywood mounting board directing them into the wall space.

Yeah, but it ain't all that hard either. Between talking with his inspectors during the permitting process and afterward, reading Wiring Simplified, and asking questions here, he should pull through OK.
I do have a permit but I don't know how receptive the inspectors are to on-site consulting. The book I have is Black & Decker The complete guide to Wiring.
 
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Old 08-27-12, 05:45 PM
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Well..yeah....but I'm pretty sure my house in VA had an up/down main.....might be wrong. Like I said...more time in the Navy panels then in any house stuff.
Years ago single phase loadcenters had mains that operated Up and Down, but that was before they were allowed to be flipped 180 degrees for bottom feeding. When they began allowing loadcenters to be either top or bottom fed, the mains switched side to side. By the way, a 3 phase loadcenter cannot be flipped 180 degrees and bottom fed as far as I am aware.
 
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Old 08-27-12, 07:29 PM
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a 3 phase loadcenter cannot be flipped 180 degrees and bottom fed as far as I am aware.
I've wired way more 3-phase panels than single-phase panels. Some of those were bottom fed, and some of those had a main breaker.
 
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