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Posted By: harold endean Re:Panels - 03/21/10 01:41 AM
Are you allowed to install a sub panel in an attic?

How about a service panel?
Posted By: Rewire Re:Panels - 03/21/10 01:45 AM
As long as you meet space and accessability requirements
Posted By: EV607797 Re:Panels - 03/21/10 01:59 AM
I see them all the time around here, especially with multiple HVAC system zones. 100A sub panel to feed two heating sections in heat pump installations is fairly common in larger homes to feed backup heat.

I consider such an installation no different that the requirement to have a disconnect for the equipment anyway. Isn't a disconnect essentially the same thing as a sub-panel for the most part? In the instances that I encounter, this is just a case of these disconnects being contained within a single enclosure.
Posted By: gfretwell Re:Panels - 03/21/10 02:31 AM
How do they get around 110.26?

If this is just a disconnect and the overcurrent protection for the branch circuit is in a properly serviceable location it is winked at but if this is the panelboard at the load end of a feeder or a tap I would really have to hear a story if I could not see 110.26(A) (1) through (3) satisfied.

There is always a nagging inconsistency in how we enforce 110.26(A). I have seen inspectors who are pedantic about the outside disconnect clearances for an HVAC condenser and then have no problems with the air handler disco stuffed in the corner of the closet with the air handler. I have seen some that you needed a skinny arm to even reach.
Posted By: EV607797 Re:Panels - 03/21/10 02:45 AM
Greg, the ones I have encountered are for air handlers with backup heat are 240V only, so there is no requirement for a neutral. The ones I've seen are 4-circuit panels with 100 amp MLO panels to house two 2-pole breakers. They are all over the place around here. I should have clarified that there are no vacant pole spaces to allow "Harry Homeowner" to add a breaker for a ceiling fan.

Nevertheless, they still are technically sub-panels.

Don't make me go there........
Posted By: frenchelectrican Re:Panels - 03/21/10 03:14 AM
I have see the subpanels in the attic but service panels once a while not very often due the POCO regulations plus local insepctors may have issue with nonOCPD'ed service entrance conductors in the attic space.

BTW Wisconsin say unfused service condutors are limited to 1.5 meter {5 feet} max

France - rather have all it outside much as possible but only allowed indoor short as possible

Unless you have main disconnection outdoor then after that it pretty much unlimited.

Posted By: Rewire Re:Panels - 03/21/10 02:46 PM
I would think ambient temps could lead to breakers tripping
Posted By: HotLine1 Re:Panels - 03/22/10 01:44 AM
I've come accross a few recently, only issue I had (As Rewire said) was ambient temps. That was addressed via adequate ventilation, installed by HVAC contractor.

As to a service panel being in the attic, as long as unprotected conductors are addressed, I see no issue.

Posted By: Rewire Re:Panels - 03/22/10 02:11 PM
We put them in unfinished basements so why not an unfinished attic,I think a permenate stair would be required.
Posted By: gfretwell Re:Panels - 03/22/10 04:19 PM
I guess I have just never seen an attic with 6'6" of headroom for the required 36x30 working space.
Since NFPA seems OK with a panel stuffed with AFCI/GFCIs in an un-airconditioned garage they must not see heat as being an issue. (in spite of most MCCBs being rated at 40C)
Posted By: HotLine1 Re:Panels - 03/23/10 01:18 AM
The McMansions have no issue with 6'6", or 36x30. A few have enough sq footage and clear ceiling heights to 'finish' into living space, if only zoning (and egress) would allow.

Posted By: gfretwell Re:Panels - 03/23/10 01:42 AM
A McMansion here would still only have a 5:12 roof and those "Mediterranean" roof lines with hips everywhere make this a maze of truss members. I guess it is just a question of what they build.
Posted By: Rewire Re:Panels - 03/23/10 02:39 AM
I wouldn't want to crawl into the attic just to reset a breaker
Posted By: gfretwell Re:Panels - 03/23/10 08:05 AM
I guess that is John's point. He sees attics where there is no crawling involved. You can walk up to the panel normally.
It would have to be that way to get my OK.
I did allow some attic mounted panels in the Ringling (the circus people) mansion but it was air conditioned space with a 7-8 foot ceiling. I still made them add a better access ladder (permanently mounted) and closer to the panel than the existing one which did require crawling over mechanicals to get to it.
Posted By: HotLine1 Re:Panels - 03/23/10 01:36 PM
Clear the air time....
The 'attic' would have to be accessable, not one that requires a portable ladder, but fixed stairs. The ceiling height of 6'6" is required, with the 30-36 clearances. A clear path from the point of egress is also necessary; no crawling thru trusses.

I have not seen, nor heard of any EC thinking about the service being in the attic, but...ya never know.

Posted By: SteveFehr Re:Panels - 03/25/10 05:31 PM
There are two entirely different kinds of attics being discussed here. One is a maze of trusses. The other is a large lofted space with a floor and headroom and easy access from a stairwell. I'd say flat NO to putting a panel in most houses in my area, but quite a few houses, especially in new england, have steep pitched or simply high-peak roofs with no trusswork and not only have quite useable space, but often full stairs up to them.

A friend of mine's attic is so large, he built a full apartment in it with stairs and everything- all finished, heated, etc. He put a full sized door opening into the attic-attic portion to use for storage and access to the HVAC equipment. In this case, the attic would easily meet all accessibility requirements, and the only problem problem I'd see with putting an electrical panel there is how hot it would get in the summer.
Posted By: Rewire Re:Panels - 03/29/10 05:00 AM
with so many better places to put the panel the attic would be my last choice
Posted By: harold endean Re:Panels - 03/29/10 01:50 PM
I have seen attics with a ton of head room and windows that open up there. Plus a lot of attics have roof fans which keep the attic at a nice cozy 90-100 deg. (F). As for work space clearances, here in NJ we have a rehab code that allows less than idea conditions for head room. (if existing). I have seen a lot of old houses with fuse boxes in their attics also.
Now granted if the attic was made up with trusses, there wouldn't be floor boards and a panel up there would be out of the question.
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