Hi,
I am installing a meterloop on a poco pole and then running 100 feet underground to a 200a main located witin the trailer.

I am wondering about the bonding and grounding here?

I would need a couple ground rods at the pole but not at the mobile home correct?

The first OCPD gets the neutral bonded right?

The panel in the mobile home needs an ISOLATED neutral bar too correct?

This is NOT like a separate building where I need a ground rod at both services is it?

I was planning on two at the poco pole and a 4 condcutor URD lateral.

I appreciate any comments or suggestions on what to watch for.

Thanks for any replies.

-regards

MUSTANG

Well, for starters, you'll need to install a disconnecting means within 30 feet of the mobile home 550.32(A). At this disconnect, you will need 2 more ground rods in addition to the two at the meter pole.

Unless you are dealing with a really old mobile home, the neutrals & equipment grounds will already be separated & waitng for that 4 wire feeder.

I don't believe that URD will be in compliance. You must pick a conductor or cable from table 310.3 Try looking into USE-2 , most brands that I've seen are also listed as RHW.

Take a look at all of Article 550, especially section III.
Tom

Hi,
I am glad I asked this question. The poco has put up a cut sheet for this type of installation.

This is the web address if you care to review it: http://www.carrollecc.com/meterinstall2.ihtml

In this installation, there is NO pole within 30 feet and NONE of the other mobile homes in this park have a second pole next to the mobile home except for an overhead drops. This goes from the meterbase and ocpd on the POCO pole to a main breaker inside the trailer 100 feet away.

You said URD was not an acceptable choice of conductors. What is URD for if not for underground feeder?

USE is the almost the same thing is it not? I am sorry to disagree but I think you are mistaken. This is an UNDERGROUND SERVICE LATERAL.

Take a look at the following link: http://www.centriccable.com/prod_MobHomeFeeder.asp

See note:Cable shall be UL Type "RHH-RHW-USE," suitable for direct burial and operation at 600 volts. Conductors shall be 8000 Series aluminum alloy. Conductors shall be color-coded.


There is no inspection for this project so all I have to go on is the poco and the NEC.

Why is a mobile home any different than any other dwelling?

I may have to revise my proposal!

Thanks for any replies.

-regards

Mustang


[This message has been edited by mustangelectric (edited 12-02-2004).]

The answer to your question is contained in the definition of a mobile home that is found in the US NEC.

"Mobile Home. A factory-assembled structure or structures transportable in one or more sections that is built on a permanent chassis and designed to be used as a dwelling without a permanent foundation where connected to the required utilities and that includes the plumbing, heating, air-conditioning, and electric systems contained therein." Copyright 2002 The National Fire Protection Association

It is the permanent chassis that makes these buildings unique because that chassis serves as an equipotential plane under the mobile home. The equipotential plane will be at ground potential if the unit is properly installed. If any fault occurs in the wiring of a mobile home the chassis is likely to distribute that stray voltage and current over the entire shell and many of the fixtures and appliances of the mobile home. That characteristic is unique among dwelling places to mobile homes. The consequences of a wiring fault being so much more likely to result in electrical shock to persons living in or visiting a mobile home justifies the additional precautions required by the US NEC.
--
Tom H

Hi,
Does art 550 cover mobile homes OUTSIDE of a MOBILE HOME PARK?

I am not sure if I m reading that right or not but it almost seems like the article is only for mobile homes in a mobile home park or the manufacture of the home itself. There are several references to mobile home parks in this article.

The installations I am looking at do not appear to meet the requirement for a disconnect within 30 ft of the exterior wall.

This would not make a lot of sense either.

Why have a meterbase with a disconnect on a pole and then run over to another disconnect on a pole within 30 feet of the mobile home then run to the main panel within the mobile home?

That three OCPD'S on a single service!

Whats the big deal anyway? I have seen less on a circuit in a nuclear plant!

Thanks for any comments.

-regards


MUSTANG

Mustang,

I've always rejected mobile home feeders that were done with URD cable unless it was also marked "USE" and/or "RHW." URD does not show up in table 310.13 Also, the few times I ran across URD, I don't recall seeing the mark of a NRTL on it. I've also looked through the UL wire marking guide and "URD" does not appear there, so I don't believe UL even evaluates this type of cable.

As far as the 30 foot requirement is concerned, it is not a requirement of the POCO it is an NEC requirement, though some POCO's do write it into their requirements. If you choose not to do this installation to the miniimum requirements of the NEC, that's your choice, but you will be creating some liabilty for yourself.

Article 550 covers mobile homes in or outside of a mobile home park, so you should comply with the rules regardless of location.

As far as your question about running over to a second disconnect, there would be no need for this if the first disconnect was within the required 30 foot measurement. This rule has been in the section on mobile homes since at least 1978 (my oldest code book) and I've been told that it goes back to the original article when it first appeared (early 1960's).

Don't be sorry about disagreeing, thats what these forums are for.

TOm

Mustang


Remember a disconnect does not mean an OCPD.

The requirement for OCP is another section.

Hi,
The URD cable I see IS UL Listed and it is STAMPED RHW. Please see the following: http://www.centriccable.com/prod_MobHomeFeeder.asp . This page shows that the cable is specifically designed for mobile home feeders. It says that the cable is RHW and that it is UL listed too. I am not clear as to where the RHW requirement is coming from. 550.33 says that the conductors must meet 310.12 and if i read it correctly the exception allows no gec between the service and the disconnect.

I understand that all i need is a unfused disconnect at the second pole.

The main problem I see is that it will be the ONLY setup like this in the WHOLE neighborhood.

I always meet the code so I will have to install this second pole.

The POCO will not allow the meterbase on any pole other than their pole out on the curb.

USE cable is no problem for me, I just happen to see the URD at the supply house and it is labeled MOBILE HOME FEEDER.

I just want to avoid any extra expense.

I may contact the state electrical inspector to see what he will say about the installation and what is going on with the rest of the mobile home on this street.

There is NOT a SINGLE mobile home out of about 100 that I looked through that had this arrangement. There is no local inspection here so I think the POCO basically set the presedence by requiring the meterbase on their pole. This saves them money on feeders.

Maybe I should go with an OH drop? from their pole to my pole within 30 feet?

The POCO acted like they had no idea about the requirement. They said that everything from the point of attachment down was the owners responsibility which I understand.

I do not go around looking at what other people have done to determine my installations but I do notice things and that got me to wondering.

Thanks for the helpful replies.

-regards

Mustang

[This message has been edited by mustangelectric (edited 12-03-2004).]

Hi,
I spoke to the POCO and they said they were NOT aware of this requirement. I also sent an e-mail to my state inspector asking for some clarification.

The POCO said that they would get up with the engineers and look into it.

They called me back and said they would be making some changes to their requirements.

They said that they now wanted a 3" conduit ran from their pole underground to a PEDESTAL within the 30 feet of the exterior wall of the mobile home.

I have seen these pedestals but have never installed one.

Aren't they just buried in the ground?

I wonder how this happens? Don't the poco have to use the NEC for its requirements? I know they are exempt from it on their own property and equipment but they should also be required to follow the code. There is a case for the fact that they are only responsible for so much but on the other hand they should not be connecting to installations that do not meet art 550.

What type of liability do they have and what about the recent installations up there that do not meet 550?

Should the state be inspecting areas that do not have a building dept? I am not trying to stir the pot.

Thanks for all the replies. I am real glad I asked about this.

-regards

MUSTANG

The POCO is almost always exempt from the NEC.


Bob

The critical question is the size of the unit. If it is an over width (>8') or over length (>40') unit or it is more than 320 square feet then it is a manufactured home rather than a mobile home. In other words anything larger than a single wide forty footer is not a mobile home. If it is a manufactured home then the service lateral can be run directly to the home under the provisions of section 550.32 (B) of the US NEC.

"550.32 Service Equipment.
(B) Manufactured Home Service Equipment. The manufactured home service equipment shall be permitted to be installed in or on a manufactured home, provided that all of the following conditions are met:
(1) The manufacturer shall include in its written installation instructions information indicating that the home shall be secured in place by an anchoring system or installed on and secured to a permanent foundation.
(2) The installation of the service equipment shall comply with Article 230.
(3) Means shall be provided for the connection of a grounding electrode conductor to the service equipment and routing it outside the structure.
(4) Bonding and grounding of the service shall be in accordance with Article 250.
(5) The manufacturer shall include in its written installation instructions one method of grounding the service equipment at the installation site. The instructions shall clearly state that other methods of grounding are found in Article 250.
(6) The minimum size grounding electrode conductor shall be specified in the instructions.
(7) A red warning label shall be mounted on or adjacent to the service equipment. The label shall state the following:
WARNING DO NOT PROVIDE ELECTRICAL POWER UNTIL THE GROUNDING ELECTRODE(S) IS INSTALLED AND CONNECTED (SEE INSTALLATION INSTRUCTIONS).
Where the service equipment is not installed in or on the unit, the installation shall comply with the other provisions of this section." Copyright 2002 the National Fire Protection Association.

You may have gotten yourself in a needles bind by referring to a larger unit as a mobile home. Call up the poco engineers and explain the situation so that they will back off the changes or the other local sparkies will be calling you everything they can think of except maybe a nice guy.
--
Tom H

[This message has been edited by tdhorne (edited 12-03-2004).]

Hi,
Thanks for the replies.

The code states that for the "purpose of this CODE and unless otherwise indicated, the term mobile home includes manufactured homes. What does that mean exactly?

Where the service equipment is NOT installed in or on the unit, the installation shall comply with the other provisions of this section. What does that mean exactly?

I am assuming that "THIS SECTION" is the complete article and not just 550.32, so in this case the 30 foot rule applies, right?

The unit is 28' x 52', WXL assembled at the site.

It is not my intent to stir up any trouble with anyone, it may happen but should I not inquire?

Are you saying that since there are other installations on the same line that are not meeting the NEC that my fellow electricians will be upset if I myself try to meet the code? That I too should follow the presedence that has already been set? Not every MOBILE HOME OR MANUFACTURED HOME on the line exceeds the limits given.

Since the Manufactured home is different from the MOBILE HOME then my mistake is that I failed to notice the difference. But that is why I am asking.

But since I have not done any work and I am only researching the installation where is the problem?

Myself I would rather have the disconnect 30 feet from the trailer rather than 100 feet. I think it is safer in a way, if I was a fireman I would want it 100 feet away!

According to what you are quoting , I do not even need a disco outside.

The POCO pays for the wire from their pole to the disconnect, all I provide is the 3" conduit, some one-hole straps and a pull string and dig the trench.

I will defer to the wisdom of the members of the site and if you all say that I am connecting a MANUFACTURED HOME instead of a MOBILE HOME then I will notify the POCO and let them know the mistake I made and make them aware of the difference.

I purchased a CSED for this installation instead of a Pedestal. I want to be able to provide for a generator connection. The owner wants it close to the building the existing cutler hammer panel is a main breaker and I am not sure if it will accept a generator kit.

Anyway, I am still glad I asked the questions here and if somebody gets mad and wants to take offense my apologies. I would rather aska dumb question than not know for sure.

One more question, if this is a MANUFATURED HOME then, I can MOUNT THE CSED on the unit istelf, correct?

Thanks again for all the help.

-regards

MUSTANG



[This message has been edited by mustangelectric (edited 12-03-2004).]

Mustang,

Yes, the 30 foot rule applies mobile home or manufactured home. I'm glad your POCO finally decided to take a gander at the NEC. They may or may not be liable for any of the existing installations where the distance exceeds 30 feet, but they could be named as a defendent in any future lawsuits. This is one of the reasons why our POCO now requires an inspection of all service entrances and the feeder to the mobile home

I have visited the site you posted & the fine print at the bottom indicates that the cable is UL listed as "USE" and RHH and RHW. These markings would be printed on the cable also.

Prior to the 2002 NEC, USE could not be used indoors at all because it did not have to have flame retardant insulation. By having the additional listing of RHW, it could be installed in a raceway & there would be no restriction on the length installed indoors. 338.10(B)(4)(b) now allows up to 6 feet of USE indoors & the cable would not need the RHW listing if it does not exceed 6 feet.

Around here, the service for a mobile home is mounted on a customer furnished 25' pole for overhead service. The installation of the feeder from the pole to the mobile home is the responsibility of the person that wants power, not the POCO. ALso, the POCO furnishes a drawing to the customer that shows the 30- foot maximum distance along with their requirements.

As a side note, I hate inspecting mobile home services installed by non-electricians, the failure rate is about 80 to 90%.

As side note #2, congratulations on doing some homework here. You'd be surprised at the number of electricians that don't even realize that there is an entire section of the code that deals with mobile/manufactured homes.

Tom

Tom,
I appreciate the professional reply. I myself will be the first to admit that although I have been around them all my life I have only installed a handful of services for mobile homes. Why? Because most people try to do it themselves. I have seen a lot of places especially in Kentucky where there used to not be any permit requirement or any requirement to have a licensed electrician or they will give the permit to the homeowner(there are a lot of places like this in arkansas) and the inspectors would basically end up directing the homeowner or whomever in the correct procedure. It may take a few trips but eventually either through a legal installation or either through frustration the connection would be made.

A lot of places go by what the inspector at the time likes to see. I know there are a lot of inspectors who post and read on this site so please do not get me wrong..I respect the inspector..myself i like an inspection, it gives me some satisfaction to have another person agree that the work i have done meets the requirements of the NEC etc.

I am not the best electrician in the world but I am not afraid of asking questions to folks I know I can rely on. I always look at the sections of the nec and I always like to hear what other electricians have to say. I think a true electrician is very interested in the work in general and chatting about the trade and it never ceases to amaze me how interesting a simple question can turn into a very educating experience.

I hope all the boys in my neck of the woods do not get the red a** over this but what is right is right and what is wrong is wrong.

I would have ended up doing it the way the concensus agreed.

I usually do not turn a screw driver until i have thouroughly researched even the simplest jobs. Residential is one of the most complex articles in the code and i learn everyday.

I found out a long time ago it does not take a big mistake to cost a lot of dollars when it involves electrical work!

I was curious to know the reasoning behind the URD comments.

I guess it just goes to prove once again that this site has a definite purpose and a long future.

Maybe 20 years from now we can look back and read this stuff and get a smile on our face when we remember the good ole days!

Thanks for all the replies.

-regards

MUSTANG



[This message has been edited by mustangelectric (edited 12-03-2004).]

MUSTANG
I wasn't trying to be actually critical of your asking and I guess I need to be clearer when I'm jesting. As I read the section you can mount your equipment on the unit since it exceeds the 320 gross square feet of floor area which makes it a manufactured home. The difference between the two is that you can readily relocate a mobile home while it is generally impractical to relocate a manufactured home. The code goes to some length to define the difference between mobile and manufactured homes. The only difference I can see in how the code treats them is that you can mount the service equipment on a manufactured home.
--
Tom H

Hi,
Thanks for the reply Tom, no explanation needed. E-mail and BBB's can tend to leave out a lot.

I appreciate the information and the advice.

I will be mounting the CSED on two 4"X"$ treated post embedded 24" in quickrete and half-strut gold and spring nuts to hold it on.

I looked at mounting on the unit but I really think that material will give out eventually. I think mounting it next to the unit (6" away) I read that the bottom of the panel should be no closer than 24" so I will watch that.

Thanks again for the replies and help.

-regards

Mustang

Tdhorne, it appears you are trying to read between the lines (of code) when it comes to the definition of a mobile home. If you read both the definition of a mobile and a manufactured home, you should realize your mistake. The code DOES NOT say that all units larger than 8X12 or 320ft.sq. are always manufactured homes. It only says that is the minimum size for a manufactured home. Mobile homes can be either bigger or smaller than the dimentions given.

triple Wrote: I believe that the essential difference is that a mobile home is mounted on a single chassis. The effect that has is that it can be moved without disassembly. A manufactured home on the other hand is built in sections and then assembled on site. In order to relocate the manufactured unit you would have to disassemble the building back into it's individual modules.
--
Tom H

Wow, what a thread. Almost to much to read, let alone understand.

In Colorado, all homes such as these are to be approved by the state. They decide if it is a manufactured home, using the UBC, or a mobile home, using the HUD standard. either way, there is a sticker mounted on it to identify it.

If it is a manufactured home, then you can put the service equipment on the outside face of the home. From there you run into a distribution panel. If the metering is over 30' from the home, then installing this equipment on the side of the home will comply with code to get the disconnect correctly installed.

You can never run into a home (manufactured or stick built) more than a few feet at the most, without an outside disconnect.

A mobile home is treated much the same, but you can never install the service equipment directly to the home. 1" to 30' away is ok, but not on it.

Another thing about USE wire. This type of cable (USE & USE-2) cannot be run into a building. The older style you mention could be run from the meter pole to the pedistal, or other outside disconnect, but not into the home. This info is in the UL white book.

I do agree that Article 550 is for all homes of this type, not just those in parks. The only thing that it does not cover is the actual wiring (inside) of the home. This falls under a federal standard, but this standard does include alot of NEC driven rules, such as GFCI etc... There are other rules that wouldn't see the light of day in the NEC, such as a panel in a closet, which is allowable under the federal standard.

Rick Miell