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Mobile Home Service Calcs- Not Necessary #187938 07/14/09 04:22 PM
Joined: Jan 2005
Posts: 5,316
renosteinke Offline OP
Cat Servant
.... And maybe even misleading.

Let's just say I' had an 'epiphany' today. The technical term for this is "oops."

The setting: someone wants to place a mobile home in a park operated by my customer. I needed to supply the service to this trailer.

So, I do all the usual load calcs, and my numbers came out at 103 amps. I instal a 125 amp service. Both the city and the PoCo are happy with this.

Then I got to discover a new bureaucracy: the Stat's "Gepartment of Business and Industry - Manufactured Housing Division." More little surprises followed.

For example, I learned that my state-issued electrical contractors' license did not cover any work I might do on, or within, a mobile home. THAT is another license, more money. I'm not even allowed to hook them up.

The next surprise was one suggested in the NEC, had I but looked closer at it. That is, the mobile home has -somewhere- a little tag on it, stating the service requirements. I have to meet these requirements. If the trailer has a 200 amp breaker, it needs a 200 amp service .... load calcs notwithstanding. In effect, the NEC treats these things not as homes, but as really big toasters.

The end result? I get to re-do my service. At least I ran big pipe!

I was also referred to, or discovered, two additional codes I am expected to meet. One is the Federal Government's "Code of Federal Regulations" (specifically, 20CFR3280), and the other is the State's own 'installation standards' (specifically, the "Nevada manufactured Home, Mobile Home, and Commercial Coach Installation Standards").

These documents are slightly different in detail than the NEC, or PoCo requirements.

Perhaps the most annoying aspect of this experience has been the reluctance of several parties to answer questions.

For example, the trailer-set guy said 'it's the code,' but was silent when I asked either what code, or what agency enforced it. The best he could say was 'the State." Well, in the entire permitting process, there had not been the slightest involvement of any state agency. How this guy was unable -or is it unwilling?- to identify the office that he regularly visited for his business is beyong my understanding.

As for the functionaries at that State office, I had to ask the same questions many times, and even then got only partial answers. For example, "Who are you? What agency? Where's your office?" The guy was specific, though, in saying my license did not allow me to work in or on mobile homes.

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Re: Mobile Home Service Calcs- Not Necessary [Re: renosteinke] #187986 07/16/09 12:25 AM
Joined: Jan 2005
Posts: 5,316
renosteinke Offline OP
Cat Servant
On a follow-up visit to the trailer, accompanied by one of the persons who was involved from the very beginning in the inspection, testing, and listing of the things, a few interesting things were quickly established.

First of all, this turnes out to be a trailer made in 1995 - and, as such, might not even be legal to instal in this town. Only if it was previously installed within the city limits can it be re-located.

Second, every exterior nameplate has either been removed, or liberally covered with paint - and cannot be read.

The only marking as to ampacity is on the panel, which says "service not to exceed 200 amps."

I did find the manufacturer's sticker under the kitchen sink, as had been suggested to me. This sticker made no reference to the electrical requirements of the trailer.

Re: Mobile Home Service Calcs- Not Necessary [Re: renosteinke] #187987 07/16/09 03:23 AM
Joined: Jul 2004
Posts: 9,571
gfretwell Offline
What is the size of the service disconnect in the mobile home?
I would think that was probably what would have been on the tag if you still had it.
When I was doing the ones for the Department of Corrections and the park system I think we put in 200s for all of them at the post.
There may have been a 150 but I don't remember one. My son in law's was 150 but it wasn't a HUD unit, it was titled as an RV, even though it was tied down on blocks.
That was just a loophole to allow things that don't meet HUD code. Florida has closed that loophole. These days you can't even move a non-conforming (wind code) mobile home. If it ever gets up on wheels, you have to take it out of state (or hide it somewhere without pulling a permit).
I assume there are conforming mobile homes by now but when the law was passed there were none.

Greg Fretwell
Re: Mobile Home Service Calcs- Not Necessary [Re: gfretwell] #187988 07/16/09 09:15 AM
Joined: Jan 2001
Posts: 1,044
Tom Offline
As far as I can tell, the whole HUD thing is a loophole, electrically speaking. I recall doing an inspection a couple of years ago on a doublewide and the panelboard was in a walk in clothes closet. The home had a HUD placard on it, so I had to sign off on the installation.

Few things are harder to put up with than the annoyance of a good example.
Re: Mobile Home Service Calcs- Not Necessary [Re: gfretwell] #187989 07/16/09 10:15 AM
Joined: Jan 2005
Posts: 5,316
renosteinke Offline OP
Cat Servant
Greg, the main disconnect is what causes me trouble; it's a 200 amp breaker.

Do, right now I'm hearing "200 amps for a trailer???" from all over the place - it seems everyone is as surprised as I. Oh well, lesson learned.

Re: Mobile Home Service Calcs- Not Necessary [Re: renosteinke] #187990 07/16/09 10:52 AM
Joined: Jul 2004
Posts: 9,571
gfretwell Offline
Apologists for the mobile home industry will say they use a different philosophy in design where every cubic inch is used in the most efficient way (similar to boats) so some rules we have in stick built homes should not apply to them. They don't want to talk about the fire statistics and the lower standard they have for insulation. One reason why they seem to have overly large services is that the HVAC system can be twice what you would have in a similarly sized house. The other problem is they tend to grow out to the edges of the property line with "cabanas", sun rooms and other site built additions, seldom permitted or inspected. These all get added load from the service.
When inspecting hurricane damage, you find these additions are the first thing to go since they are generally aluminum, vinyl and glass affairs, put together with sheet metal screws. They seldom meet any similance of a building code.

Greg Fretwell
Re: Mobile Home Service Calcs- Not Necessary [Re: gfretwell] #187992 07/16/09 03:26 PM
Joined: Jan 2005
Posts: 5,316
renosteinke Offline OP
Cat Servant
What can a mistake cost?

Well .... being in debt to the max, and completely lacking in other work .....

Mind you, this issue has not 'officially' become a problem. That is, the trailer has not been even scheduled for inspection by the mobile home folks. I billed this job when my permit was signed off on. payment was supposedly sent last Friday - and I became aware of this issue only on Tuesday.

Well, you guessed it .... the check was not sent, and will not be sent 'until the job is done.' I don't even have the gas to get there.

That's it - I'm sunk ... and I have told the customer so. I'm out of business. I am trying to steer this job to a reputable contractor.


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