[evermod]

Hi all,

I'm looking at a meter/panel combo mounted to the exterior wall of a house, there are a couple things I'm not happy about. I've made two drawings to help desbribe the situation:

First pic is of the exterior, second shows the backside where the wires are routed through a rough hole chiseled out of the exterior stucco. The cables are properly clamped into separate knockouts in the panel so at least there's that. There currently is no sealant or gasket of any kind between the wall and the panel; pretty sure this doesn't meet any kind of standards for a legit install. I'd like to change things to something less cringe-inducing. I'm also not opposed to re-routing the cables through the knockouts on the bottom of the panel exterior; would like some ideas on how to best handle this.

 

[HandyAndyInNC]

Has this work already been completed? If so, was there a specification in the contract about the way you wanted the conductors ran thru a wall? Did you specify that all conductors be ran out of the bottom? This is another place where conduit or a wire trough be used to make a clean route from the meter to the breaker box inside. Did you specify any of those things? Why would you have both the meter and the breaker box outside? Just the meter should be outside. Everything else should be inside. I would have specified that everything between the pole and the breaker box be in conduit. Yes, there still would have been one hole, but it is easily sealed with caulk. People will go the cheapest and fastest way to do the work. And that is what I see here. Unless you specify and both parties sign off on that as agreed, they can run the conductors as they please. There is nothing that is not under the umbrella of the NEC that was done. Asking these questions after the fact is a lot more work to change.

 

[chandler48]

You can't expose NM cable to the elements. Routing them through the back is the best way to do it. If you want a semi-hermetic seal, use OSI Quad Max on the top of the meter base/breaker panel down the two sides and across the bottom with a small gap to allow moisture to exit. It will keep rain water, etc. from encroaching. Are you, by chance, in Colorado?

 

[Jim Port]

You should not have individual conductors leaving the panel.

 

[chandler48]

I noticed at my daughter's house in Colorado, their breaker panel is outside, next to the meter base. All their wiring goes out the back of the panel to distribution.

 

[evermod]

You can't expose NM cable to the elements. Routing them through the back is the best way to do it. If you want a semi-hermetic seal....

You should not have individual conductors leaving the panel.

I'm located in So Cal if that makes any difference. Regarding NM vs individual conductors, I figured if I was going to add anything run through conduit it would not be NM. Back to that hole in the wall, my concern over the lack of weatherproofing has less to do with my preferences and more to do with what an inspector might expect to see here. While the drawings convey the gist of it they make it appear much better than it actually is; I suspect if I just posted a pic of what's there it would be considered a prime example of half-assery (all done before my ownership, btw). As it stands, all it would take to get moisture into the wall cavity would be a a couple hits to the exterior with a pressure washer.

Some searching turned up this thread:

https://www.diychatroom.com/f18/how-rough-opening-main-panel-585730/

The OP had some concerns over how the transition from panel to the walls interior should be configured, similar to mine. Pics of his box appear to show some sort of boot or grommet around a big ol' bundle of NM shoved through. Pretty sure this is only slighly better than my example from a weatherproofing standpoint. Unfortunately this thread didn't yield much in the way of solutions.

If all it takes to fix this situation (and make an inspector happy) is forming a gasket with some sealant then I'll do just that. However, I do find it hard to believe that there isn't a very specific way to handle this.

 

[evermod]

I noticed at my daughter's house in Colorado, their breaker panel is outside, next to the meter base. All their wiring goes out the back of the panel to distribution.

Where I am, exterior mounted meter/load center combos were the norm for a long time, some recessed and some surface mounted. In fact, some neighbors down the block, whose homes were build much, much later (80's) have similar meter/load center configs. About the only time you see conduit going in or out of a meter/load center combo around here is to accomodate later work and/or subpanel additions.

 

[seharper]

And they'll be back. NEC 2020 requires a disconnect be outside the building. Once the builders optimize for cost, it'll mean outdoor main panels all over again.

 

[EdLank]

A mandated shut off outside the house? Does that not make it pretty easy for someone to do damage to a property by turning off power, and if the entire panel were out there, play games by choosing specific circuits to kill, like heat?

 

[Jim Port]

It would give miscreants that option for mischief.

 

[jbfan]

A mandated shut off outside the house? Does that not make it pretty easy for someone to do damage to a property by turning off power, and if the entire panel were out there, play games by choosing specific circuits to kill, like heat?

Never in all my years have I had a customer complain about that.

 

[Oso954]

The exterior disconnects have been required for many years in some jurisdictions by local amendment. They are sometimes referred to as fire department disconnects. They allow the FD to kill power to the building before they start spraying water around.

If you have a solar system, you would also be required to have a second disconnect for it.

With our climate (at least in most areas) the outdoor main panel isn't a problem. You have more working space around them than most interior panels would have. Most people don't pile stuff in front of them or otherwise infringe on the work space.

And no, people generally don't play around with your electric service.

 

[betelgeuse]

If you're that worried about tampering....All external panels (NEMA 3R) have means for padlocking.

The FDs carry bolt cutters.

 

[seharper]

Exactly! NEC 2020 doesn't say you can't lock it.

I can tell you they were hugely helpful when we had our lost-neutral incident last year, the lineman had to rework both our connection and the next door neighbors, so (I was hanging around to watch and gofer so he wouldn't have to bring the bucket down) he sent me to warn and shut off the neighbors. I could do it easily. I gather in indoor-main-breaker states, the crews just jumper it...

 

[evermod]

If some clown-hat was hell-bent on messing w/you, given the choice between spray- painting your wall, lobbing a brick through a window or playing w/your breaker box I think one or both of the first two will win out every time.

I don't think there's a padlock made that can scare off a fireman's axe, they might have second thoughts on axeing live wires though, vs gaining access to a switch. I would have no problem locking a panel IF I was afraid of leaving it unlocked.

Back to installation issues, I found this which is sure to stir things up and create more questions:

https://forums.mikeholt.com/threads/article-312.89164/

It deals with the requirement for an open airspace behind an exterior-mounted metal panel cabinet. Seems like hardly anybody enforces this requirement and even fewer bother to attempt some form of compliance.

Say somebody had the wild idea of meeting the 1/4" airspace requirement, well then wires clamped to randomly spaced rear knockouts make less sense. As I see it one has a few choices: they could form a fat gasket immediately around the area occupied by the clamped wires or run a large diameter very short length of conduit connecting the cabinet to the wall cavity thus giving you one, round hole to seal around. Or would two separate mid-size diameter conduits be better? Concerning the conduit approach, what should it look like on the inside and what can be run through?

 

[Jim Port]

Although done in some areas, there is no code acceptable way to enter the back of the panel through a large conduit sleeve.

 

[evermod]

Although done in some areas, there is no code acceptable way to enter the back of the panel through a large conduit sleeve.

I read about such things not raising any flags in some locales but hearing you say there's no applicable code makes sense to me. Too many ways this could go wrong I think, like somebody stuffing the sleeve full with as many NM cables that'll pysically fit. So that idea is out.

I'm also finding threads on the technical aspects of NM running to an exterior panel (damp/wet location). Something that seems to get done quite frequently although it shouldn't pass(?).

With that, I'm looking into running dual-rated conductors through flexible liquid-tight NM conduit from the panel up to J boxes in the attic, transition to NM cable at that point. Does anybody see any problem with this? The main attraction here is being able to transition from a horizontal to vertical route w/o having to use an exposed 90deg conduit body or pull box inside the house; that is unless there's reason I can't use these in the wall cavity behind the panel:

http://www.aifittings.com/catalog/liquid-tight/45-degree-non-metallic-connectors/