200A Panel with less than 4/0 aluminum

[Doc13067]

I just looked at a job for installing mini splits in a modular home. I saw a Siemens 200A panel that looked about 20 years old with 4 vacant spaces. Just to make sure, I took the cover off and found service wires that are way too small, or so I thought. I didn’t have much time and will go back, but what I saw were aluminum wires that were definitely not 4/0. The panel had an inspection sticker on it so I’m baffled. These wires were 2/0 at best. Has anyone ever seen this? Is there something I’m not aware of or is this a major problem....

 

[jeff48356]

If the wire is 2/0, then just change out the main breaker with a 150A. The entire load of the home will likely never be anywhere near even 150A, especially if major heating appliances are gas-fired.

 

[Little Bill]

Look at the outside disconnect where most services for mobile/mfg homes is. They may be feeding the inside with less than 200A but just used a 200A panel.

 

[Doc13067]

Ah ok thank you good thinking! there may be a disconnect. There certainly are 4 wires coming in the bottom of the panel. However, the panel is bonded. Something is not right somewhere. But I like the idea of changing the main breaker if this indeed is not a sub panel.

 

[Doc13067]

So mobile homes commonly have a disconnect outside somewhere?

 

[augie47]

550.32 Service Equipment. (A) Mobile Home Service Equipment. The mobile home serv ice equipment shall be located adjacent to the mobile home and not mounted in or on the mobile home. The service equipment shall be located in sight from and not more than 9.0 m (30 ft) from the exterior wall of the mobile home it serves. ............................................................................................

 

[Doc13067]

Oh wait disregard, it is not bonded. I just noticed separate ground busses. So you are right! It’s a sub panel with a main somewhere with a lesser rating. I’ll find it next time. Thanks for the help.

 

[Fred B]

So mobile homes commonly have a disconnect outside somewhere?

Find the meter, it's usually there. Requirements for such in 550.32
Augie you beat me just went to post and it updated

 

[Doc13067]

550.32 Service Equipment. (A) Mobile Home Service Equipment. The mobile home serv ice equipment shall be located adjacent to the mobile home and not mounted in or on the mobile home. The service equipment shall be located in sight from and not more than 9.0 m (30 ft) from the exterior wall of the mobile home it serves. ............................................................................................

Thanks very much. I’ll read this article. ive only done work on a mobile home once in 15 years of doing this.

 

[AC\DC]

check to see if it has a name plate on the house saying that it must be feed with 200 amp service. A fellow GC ran into this same situation and inspector would not pass without the 200 amp. property is vacant cause owner. Cant afford to fix it

 

[James L]

I just looked at a job for installing mini splits in a modular home.....

550.32 Service Equipment. (A) Mobile Hime Service Equipment......

OP said it's a modular home.

Modular Homes are not mobile homes

 

[AC\DC]

Correct and they have a plate on them stating 200 amp supply only.

 

[david luchini]

OP said it's a modular home.

Modular Homes are not mobile homes

He also said it's a mobile home...twice

So mobile homes commonly have a disconnect outside somewhere?

Thanks very much. I’ll read this article. ive only done work on a mobile home once in 15 years of doing this.

 

[James L]

He also said it's a mobile home...twice

I'd say he needs to figure out which one it is

 

[Doc13067]

Just to clear this up, my question was regarding a modular home that I looked at yesterday. I was given some much appreciated help and directed to a code section about mobile homes. When referencing that code section I inquired about mobile homes because that was the language in the referenced code and I referred to work I did in a mobile home many years ago, which was my only experience working on a (let’s call it a residence without a permanent foundation in the ground) residence without a permanent foundation in the ground, which is the reason for both my ignorance on the subject and for posting the question. Rest assured I will soon know if there is a difference and what that difference is between mobile and modular homes, especially since by your pointing that out I gather there must be some significant difference in their respective electrical systems.

The crux of the matter was that I was stumped to find what I believed to be insufficiently sized service wires. Little Bill, Fred B, Augie, and AC/DC pointed me in the right direction to study the codes and made me see that the wires are merely feeders coming from a disco, most likely less than 200 Amps. So is there a different code section for modular homes or is the electrical system the same as what’s referenced in 550.32?

 

[Little Bill]

I don't think the term "modular" is used in the NEC. The term used is "Manufactured" For the most part, mobile home and manufactured home are treated the same. One exception is the service disconnecting means is permitted to be located on or in the home, providing the requirements in 550.32(B) are met. The service disconnect for a mobile home is not permitted to be on or in the home. Take note, that although a manufactured home is permitted to have the service on/in the home, it is not required.

 

[James L]

Just to clear this up, my question was regarding a modular home that I looked at yesterday. I was given some much appreciated help and directed to a code section about mobile homes. When referencing that code section I inquired about mobile homes because that was the language in the referenced code and I referred to work I did in a mobile home many years ago, which was my only experience working on a (let’s call it a residence without a permanent foundation in the ground) residence without a permanent foundation in the ground, which is the reason for both my ignorance on the subject and for posting the question. Rest assured I will soon know if there is a difference and what that difference is between mobile and modular homes, especially since by your pointing that out I gather there must be some significant difference in their respective electrical systems.

The crux of the matter was that I was stumped to find what I believed to be insufficiently sized service wires. Little Bill, Fred B, Augie, and AC/DC pointed me in the right direction to study the codes and made me see that the wires are merely feeders coming from a disco, most likely less than 200 Amps. So is there a different code section for modular homes or is the electrical system the same as what’s referenced in 550.32?

In my opinion, the verbiage in the code is a bit messed up. When you look at the definitions in article 550, you see mobile home and manufactured home.

The difference is that a manufactured home is morecthan 8 feet wide and 40 fert long, or bigger than 320 square feet.

In other words, what the code calls a mobile home, real people call a travel trailer.

And what the code calls a manufactured home, real people call it a mobile home.

Either way, they're both assembled onto a permanent chassis - wheels and all

A modular home is a real home that's built in sections, and put onto a permanent foundation.

 

[Fred B]

In my opinion, the verbiage in the code is a bit messed up. When you look at the definitions in article 550, you see mobile home and manufactured home.

The difference is that a manufactured home is morecthan 8 feet wide and 40 fert long, or bigger than 320 square feet.

In other words, what the code calls a mobile home, real people call a travel trailer.

And what the code calls a manufactured home, real people call it a mobile home.

Either way, they're both assembled onto a permanent chassis - wheels and all

A modular home is a real home that's built in sections, and put onto a permanent foundation.

Travel trailers in code are covered in 2017 NEC section 551. RECREATIONAL VEHICLE AND RECREATIONAL VEHICLE PARK

As to your differentiation between manufactured home and a modular home, the only real difference is the lack of a perminant steel structural frame. They both are covered in Article 550. And exempted from a lot of requirements that a stick built house would have to comply with.
This is a factor in manufactured houses of all types, "mobile home", "double wide", or "modular" they all are exempted from many of the building codes that would effect a "stick built" house. If you are building a stick built you are held to a much higher standard both in construction, mechanicals, as well as electrical installation than are "manufactured" homes.
I've worked for a while doing installation of both "modular" and "double wides" not involved with the electrical but did take notice of the subpar installation (from a stick built perspective), both were notorious for mis matched connecting points, both electrically, plumbing, and heating in addition to even the physical dimensions. Worst I've seen was a "mis sized" by over 3 inches, made it interesting to get the siding installed on gable ends. They build to a minimum HUD standards and really stick to doing that to the most minimum that they can "get away" with. Electrically I've seen many with "flying splices" when the sections didn't quite line up, they most times used "boxless splices" (a specialized connector allowed in a manufactured home) but not always. And for those who hate AFCI's, get a manufactured home, they don't use them, exempt, even though NEC 2017 550.25(B) calls for it.
https://www.ecfr.gov/cgi-bin/retrie...n=pt24.5.3280&r=PART&ty=HTML#se24.5.3280_1801

 

[kwired]

In my opinion, the verbiage in the code is a bit messed up. When you look at the definitions in article 550, you see mobile home and manufactured home.

The difference is that a manufactured home is morecthan 8 feet wide and 40 fert long, or bigger than 320 square feet.

In other words, what the code calls a mobile home, real people call a travel trailer.

And what the code calls a manufactured home, real people call it a mobile home.

Either way, they're both assembled onto a permanent chassis - wheels and all

A modular home is a real home that's built in sections, and put onto a permanent foundation.

IIRC from a long time ago - mobile homes are built to HUD standards.

Manufactured homes sort of a hybrid similar to mobile homes but still mostly assembled in a plant, but can be in sections and some final assembly is done on site. Usually still have steel chassis like mobile homes but wheels/axles may be removed once on site.

Then there are other homes that are basically manufactured (usually in sections and those sections built in a plant) but don't have a permanent steel chassis attached to them. I don't think these qualify as mobile or manufactured homes per NEC.

 

[retirede]

I think the bottom line is that a mobile home can be relocated rather easily, hence the requirement to be able to deenergize away from the structure.

A modular home, once installed on site is more permanent.