I am from Canada and supply electrical residential panels to a modular (mobile) home manufacturer. We are having a slight problem with the total number of circuits available in a single panel. We use either a 200A service (max. 40 circuits) or 100A service (max. 30 circuits).
My client is telling me he doesn't have enough space available to handle all the circuits required. I can't believe that a modular (mobile) home could use more than 40 circuits. However, let's say he does need more than 40, I need to know how many dedicated circuits are required by NEC for a single family residence. Such as AFCI (varies with number of receptacles in bedrooms), fridges, microwaves, GFCI breakers in kitchens, garages, bathrooms, washers/dryers, stoves.
If we find that my client is correct, that he needs 40 + circuits are there any suggestions as to how to accommodate this? Pony panels, one safety switch feeding 2 panels?
I really appreciate your assistance and look forward to your replies.
In order to determine the panel size, you should first-off have laod calculations for the mobile home. This dictates the service capacity required, although you can increase to amperage, with the utility co. blessings. IF you have a circuit quantity problem, you can install a sub-panel to gain additional branch space.
A 200 amp main (or 225 amp MLO) panel provides 40 or 42 circuits, maximum, as mandated by the NEC.
It seems unusual that you could have 40+ circuits in a mobile home. Is the heat electric??, along with the water heater, dryer, etc??
You can find a listing of the required circuits in the current NEC that is in force in your area John
These forums sure can humble oneself. What is a 'Pony panel? As you come to my rescue again. If I understand this correctly, Ken is talking about a MOBILE HOME, which is governed by Art 550. I can see his concern, the equipment can get costly.
HotLine1 (John). The size and amperage of the panel has been determined by the mobile home manufacturer and I would presume the supply authority and what size of service they are going to supply.
I understand the NEC mandate about maximum number of circuits but my client is having a tough time laying out the circuits in the mobile home. You see in Canada we have no restrictions on the number of circuits. That is, we can turn a 40 circuit 200A panel into nearly 80 circuits, the only restriction being that we need to use AFCI and GFCI breakers that take the full 1" or 2" spaces. The feeling here is that you still can't overload the panel, because you are still restricted by the amperage carrying capacity of the main device. Besides we are finding here that people are wanting separate dedicated circuits for fax machines, computers, in home offices. We have 12 poles in our panels that are dedicated and assigned for specific circuits - such as dryer, receptacle in laundry area, fridges, microwaves, washers, stoves, etc. So even a 32 circuit panel doesn't work without going to twin mounted breakers or quad type breakers.
That's the problem John, I don't have a current NEC book to reference and so I need some information regarding, I guess Art 550 as indicated by Pierre.
I thought it would be helpful to find out what specific circuits require their own dedicated breaker, see what's involved and once those are determined, then we know how many circuits we have left to do the "general wiring". As you can see from above in Canada you just keep adding breakers until you cover the circuits, with the U.S. requirements there is a little more work involved.
Bill Addiss (Bill). The number of circuits (40 and 30) are based on full size 1" wide breakers. That's what I need is the number of GFCIs, AFCIs, etc.
PCBelarge (Pierre). I guess that the word "Pony Panel" is Canadian lingo for sub panel. And you are correct that this is why my client doesn't want to use them, it adds a lot of cost to an all ready competitive product. Not just the panel but the extra feeder lengths, added breaker. This is why we don't have the same issue here. We can double up on the number of breakers. In the U.S. market you have definite restrictions.
I wonder if your client thinks that all of the additional "dedicated" circuits are necessary? Sometimes people think every electronic device needs a dedicated circuit when in fact it will opperate just fine if the wiring is installed properly considering any shared "neutral" conductors. Not to mention proper grounding practices.
My suggestion would be to ask for a list of expected equipment and their electrical demands. Based on that information, you will be able to help determine the circuitry for the unit.
Hope this helps! Dave
[This message has been edited by WebSparky (edited 07-03-2003).]
With either a large number of circuits, or incremental changes (re-model, additions, modular design), I begin to like the use of sub-panels. With sub-panels, more circuits are available, and the main panel's breakers serve to feed the sub-panels. The cost of a small panel is more than offset by the labor saved, and trouble-shooting eased.