I am designing a place for myself and easiest place to route the underground electric service to is the outside wall of the garage. We are in a rainforest climate where it hovers around freezing and rains six days a week in the winter. The garage will be unheated. Should I be concerned about condensation inside the electrical panel? (A new house just built a couple of lots over from me has this exact setup and at first glance it seemed unwise to me. I mean if you bring your soaking wet car in there every day and it evaporates from the engine heat and then that vapour tries to condense somewhere I am afraid it will be the bus bars or breakers!)
thanks
John
Replies
Maybe....
.......consider a OCPD protected main disconnect only in the garage and move the breaker box into a more hospitable location inside of the conditioned space?
At least you would only be subjecting the disconnect to this environment.
Underground feed > meter pan > OCPD equipped disconnect inside of garage > SEP also equipped with a main breaker inside of the dry house.
Just a thought...
Jim
climate where it hovers around freezing and rains six days a week in the winter
must live down the street from me?
Pumphuse, barn, carshop, and a couple of sheds have their own panels, unheated. Going on 40 years for a couple of them, no problems so far......
...went 60 days once without seeing the sun. Summers however are dry, sunny, low humidity, warm (not too hot) and no bugs to speak of.
Junkhound, that is encouraging to hear. I guess my concerns are unfounded.
John
I can't speak for your climate in particular, but throughout much of the US South you see electrical panels on the outside of homes, protected from the weather only by the roof overhang. While I'm sure this does the panels no good, it doesn't seem to cause grevious harm, and it's not prohibited by code, so long as the panel enclosure is listed for use in an exposed situation.
First thing you need to do is read the Power company rules for locating your servicer. In most cases, you can find them at their web site.
You'll need at least the meter and a disconnect outside, where anyone can get to it. That's where the utility's wires go.
After that, you can put the panel nearly anywhere. Indeed, you can have several panels, each in a different location.
Electrical gear that is specifically rated for outdoor use will have plenty of places where condensation can drain out the bottom. Those enclosures are not even close to being sealed. Don't try to seal them, either!
And if you were really worried about this you could place a small heater near the bottom of the panel. I'm not sure exactly where you'd procure an appropriate heater or what would be needed to make it legal code-wise, but a 10-20 watt heater in the bottom of a closed panel would be sufficient to prevent condensation in most cases.
25watt lamp
we do that at work on outdoor electrical cabinets. Not the best for your green home though!
I would worry more about rot and mildew than damage to the panel. What do people do for hunidity control in general there?
rainscreen, decent roof overhangs, pray.....
Panel location
Like Amish electrician said. Service entry to the meter base and disconnect outside the garage, Then put the main panel in the house. By doing it as he suggested, you can located it for shorter home runs of the wiring. That alone will save you money and worry.
Suggest you get a licensed electrician for your install.
The problem there can be the clearance requirements. In many homes it's hard to find a suitable area that has the required (even if fictitious) clearance and accessibility, plus reasonable proximity to the areas to be served. In a garage you've inherently got the (fictitious) clearance, though proximity may be a problem. (Fictitious because there will always be stuff stored around it.)
Clearnces
Disconects are located outside the dwelling.
Clearances are met by them being next to the meter base.
Once a dissconect is installed, you can install your panels, or panels, inside the house where hey are convienent for shorter wire runs. A W/T knife disconect is cheaper than a W/T main panel.
Our electrical code is different than yours. There is no disconnect switch, the utility company just pulls the meter. The main breaker must be in the same panel box as the individual circuit breakers ("load centre").
Now the critical part - The portion between the meter socket and the main breaker "inside" the structure must be as short as possible (like 5.5" through the wall) or concrete encased. I believe this is due to that portion of the service connection being unprotected by the main breaker.
(I've got plenty of experience wiring homes and did my last place which passed three (3) levels of electrical inspection (utility company, city electrical and city building department (checking interconnection of smoke detectors etc). My main concern with this one is the concept of a panel in an unheated garage.)
Thanks
John
Electrical code
I'm sure you are quite capable of wiring your home. I didn't mean to insuate that you weren't.
Probably 95% of all residential service entrances are as you decribe, but the NEC does allow fro other methods of installation. Artical 230 and section 230.70 specifcaly cover service disconnecting means.
That is the reason I sugested you hire an electrician. Even if you don't want him to do the actual work it would be worth a few $$ to know that there are alternatives to what you know or have experienced. He will know not only the NEC but any local exceptions or additions to it.
Just for everyones general information the service disconecting means is not necessarily for the just the utility company's use. It provides a means for emergency personel to dissconect power to a structure. In most residential install this is accomplished by pulling the meter at the meter base, but the requirement may also be met by installing a dissconect switch, either fussed or a simple knife switch or automatic switch, i.e. circuite breaker.
One little trick you could do: Place the breakers that carry continuous load (refrigerator, commonly used lighting, AC, if that is run a lot, etc) low in the box. (Note that panel specs may limit the size of breakers in the lower portion of the box, so check that.) All breakers generate a little bit of heat, and if you can distribute that heat through the box (heat rises) then you'll have that critical fraction of a degree temp differenced needed to prevent condensation.
DanH - that's a good trick!
(NEC doesn't apply to us, we're in Canada)
Thanks all.
John
If you buy the proper enclosure that is rated for outdoors, you won't have any problems. Buy good breakers too. You will get decades of use out of them outside.