insulation behind electrical panel

[gumbudah]

I'm installing a squar d qo main electrical panel in my garage, which is built from 2x6. Since the box is only about 3.5" deep, I plan to fill behind it with polystyrene insulation board. Any problem using polystyrene behind the main panel as far as contact/heat creation?

 

[Teken]

Normally the panel needs to be affixed to a wood panel, what ever is underneath the wood at that point is fine . . .

 

[gumbudah]

This will be a flush mount so, the box is recessed into the stud cavity about 3". There are holes in the side of the box, so I've mounted it through the sides to the studs. I put 2" of rigid behind it. Too bad I forgot that I needed to secure the PVC coupling to it prior to mounting it! oh well, it's only four screws.

 

[tfi racing]

Normally the panel needs to be affixed to a wood panel, what ever is underneath the wood at that point is fine . . .

I have never seen that requirement anywhere in any code book,please elaborate.

 

[Norcal]

I have never seen that requirement anywhere in any code book,please elaborate.

It's not required, but "customary" when it is residential panel surface mounted, the OP's panel is flush mounted.

To answer the original question, I see no issue with insulation behind the loadcenter.

 

[nehog]

I'd think that any insulation should be fireproof (fiberglass) however... Just makes sense.

 

[gumbudah]

On the fireproofing, it'd be probably a good thing, but I have two comments.
1. rigid provides r5/inch, I have 2 inches available, so R10, whereas fiberglass will be a little over 3/inch so approx r6-7. I'd like to get as much as possible.
2. As I've read in other forums, and as I understand it, elecrtical panels should not heat to the point of causing combustion in a wall. Yes, a little excess heat maybe, but shouldn't be significant unless there is a loose wire somewhere that's causing an intermitten/arcing/high resistance situation that would elevate temps....
That said, thanks for the feedback!

 

[nehog]

The fireproofing is more when things go 'wrong' as in you have a fault (lightning strike for example) and a major arc-through. The loss of a little R value around the box should not be critical...

 

[WVBrady]

I have been wondering the same thing. What I was concerned about was, without insulation, would there be a problem with condensation?

 

[351cmach]

I have been wondering the same thing. What I was concerned about was, without insulation, would there be a problem with condensation?

I have this same question.

I have my panel recessed between 2x6 studs, behind the panel is not insulated. I just had the walls plastered and now notice I have condensation in the panel. Its still very humid in the garage. I know the condensation will lessen. when things dry out. Should I insulate behind the panel or will it be ok in the future when the cover is on and things dry out?