mobile home & ground rods

[renosteinke]

Everything seems to depend upon the mobile home being considered as a'structure.'

With that UL label, a case can be made that it is complete, as is, and is simply an appliance- and not a structure at all.

 

[david]

That is because you seemingly are expecting Article 550, either by entry or specific reference, to be an all encompassing instruction manual. It is not. :slaphead:

Actually I don’t But what I am doing is this
550.33 amends the general requirement in article 250 by referencing 250.32(B) instead of 250.32

I am saying there is a difference in referencing a specific section of 250,32 as in this case 250.32(B) I am also saying that difference was deliberate

I am saying it would not change your position had 550.33 referenced 250.32 instead of 250.32(B)

you seem un willing to recognize that that difference was deliberate. When you couple that difference with 550.16 it seems pretty clear to me That 550 doesn’t just modify the requirements in 250 but amends them spacific to mobile / manufacture homes

 

[david]

[QUOTE
That is because you seemingly are expecting Article 550, either by entry or specific reference, to be an all encompassing instruction manual. It is not. :slaphead:

Actually I don?t But what I am doing is this
550.33 amends the general requirement in article 250 by referencing 250.32(B) instead of 250.32

I am saying there is a difference in referencing a specific section of 250,32 as in this case 250.32(B) I am also saying that difference was deliberate

I am saying it would not change your position had 550.33 referenced 250.32 instead of 250.32(B)

you seem un willing to recognize that that difference was deliberate. When you couple that difference with 550.16 it seems pretty clear to me That 550 doesn?t just modify the requirements in 250 but amends them spacific to mobile / manufacture homes[/QUOTE]

Actually 90% of the manufacture instructions i look at last night on line reqonize this differance as well

 

[Smart $]

Actually I don?t But what I am doing is this
550.33 amends the general requirement in article 250 by referencing 250.32(B) instead of 250.32

I am saying there is a difference in referencing a specific section of 250,32 as in this case 250.32(B) I am also saying that difference was deliberate

I am saying it would not change your position had 550.33 referenced 250.32 instead of 250.32(B)

you seem un willing to recognize that that difference was deliberate. When you couple that difference with 550.16 it seems pretty clear to me That 550 doesn?t just modify the requirements in 250 but amends them spacific to mobile / manufacture homes

You make a fair point. Doesn't change my position though... and I am willing to recognize anything substantial. The problem I have with this line of thought is that you are assuming "the difference is deliberate". And you still haven't pointed out anything which says the entirety of 250.32 don't apply. Bob (iwire) pointed out earlier just what specific relinquishments look like.

Additionally, you bring up 550.16. The general requirement ends with the statement, "Where the distribution panelboard is the service equipment as permitted by 550.32(B), the neutral conductors and the equipment grounding bus shall be connected." No mention of a grounding electrode system here, and we all know it is required where the distribution panelboard serves is the service equipment.

Actually 90% of the manufacture instructions i look at last night on line reqonize this differance as well

And I just did a quick search and found the same debate going on in another forum. In one of the posts:

"the two arrangements for service equipment installation and their associated grounding requirements are specified in 550.32(A) and (B). Section 550.32 (B) covers service equipment mounted on or in the mobile/manufactured home. Section 550.32(A) requires grounding at the service disconnecting means in accordance with 250.32. This arrangement where greater than 30 ft from the mobile home facilitates the installation of feeders to the required mobile home disconnect. The establishment of a grounding electrode system at the mobile home is required in order to comply with 250.32(A) and the grounding and bonding requirements of the feeder is required to comply with 250.32(B). Section 250.32(B)(1) requires the equipment-grounding conductor to be connected to the building or structure disconnecting means (see Article 225) and grounding electrode in the equipment supplied by the feeder or branch circuit. Additionally, 250.54 does not prohibit the installation of auxiliary grounding electrodes in the area of electrically operated equipment."

Quoted by :

Mark Cloutier

NFPA Senior Electrical Engineer


​

Here's a direct link to that post:

http://www.inspectpa.com/forum/show...-and-ground-rods&p=68062&viewfull=1#post68062

 

[Smart $]

Everything seems to depend upon the mobile home being considered as a'structure.'

With that UL label, a case can be made that it is complete, as is, and is simply an appliance- and not a structure at all.

Switchgear and most other electrical distribution equipment are also UL listed. Doesn't prevent them from being considered a separate structure.

 

[david]

You make a fair point. Doesn't change my position though... and I am willing to recognize anything substantial. The problem I have with this line of thought is that you are assuming "the difference is deliberate". And you still haven't pointed out anything which says the entirety of 250.32 don't apply. Bob (iwire) pointed out earlier just what specific relinquishments look like.

Additionally, you bring up 550.16. The general requirement ends with the statement, "Where the distribution panelboard is the service equipment as permitted by 550.32(B), the neutral conductors and the equipment grounding bus shall be connected." No mention of a grounding electrode system here, and we all know it is required where the distribution panelboard serves is the service equipment.

Ok just for clarity Ii am going to break this down in three sections

!. The service equipment (enclosure) No particular distance requirement but must be supplemented if greater then 30 ft,

2.The Disconnect (not required but allowed with in 30 ft

3.The manufactured home distribution panel.
so lets build this backwards

The feeder is required to connect the distribution panel to the service
So lets look at the service equipment

550.32
550.32 Service Equipment.
(A) Mobile Home Service Equipment. The mobile home service 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. The service equipment shall be permitted to be located elsewhere on the premises, provided that a disconnecting means suitable for use as service equipment is located within sight from and not more than 9.0 m (30 ft) from the exterior wall of the mobile home it serves and is rated not less than that required for service equipment per 550.32(C). Grounding at the disconnecting means shall be in accordance with 250.32.

Any thing special required
• Adjacent to not on
• With in 30 ft of the exterior wall
• Must be rated per 550,32(C)
Everyone agrees ground rod required
Allowances:
Can be further than 30 feet if a supplemental disconnect is installed 30 feet or less (not service equipment)
BUT:
Must be suitable for service equipment
And a ground rod required not optional be cause of the reference to 250.32

Now back to the distribution panel in the mobile home
Does it have to be suitable for service equipment unless I am missing something it does not.
Are there any special requirements called out for the distribution panel?
Are there any references any where directly stating that the distribution panel is required to be connected to a grounding electrode
No there is not

Now look at the feeder between the disconnect panel and the service the reference to 250,32(B) tells us how the feeder must be connected. And to point that the neutral was be un-bonded

Remember the mandate for the grounding electrode was found in service equipment because this disconnect is optional not required to act in place of the service disconnect

Now look at the feeder from the service to the distribution panel in the mobile home the reference to 250.32(B) and again tells use how the feeder is to be connected and to point the neutral must be un bonded

 

[david]

Additionally, you bring up 550.16. The general requirement ends with the statement, "Where the distribution panelboard is the service equipment as permitted by 550.32(B), the neutral conductors and the equipment grounding bus shall be connected." No mention of a grounding electrode system here, and we all know it is required where the distribution panelboard serves is the service equipment.

yes i agree that the grounding electrode is required in that example

i agree it is not mentioned but I am more focused on what is referenced
550,16 specifically references 550.32(B)

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:



(2) The installation of the service shall comply with Part I through Part VII of Article 230.

(4) Bonding and grounding of the service shall be in accordance with Part I through Part V of Article 250.

(6) The minimum size grounding electrode conductor shall be specified in the instructions.

 

[hurk27]

Most trailer parks here in this area will have either a metered service pedestal located adjacent to the home (within 2-5') or a disconnect again adjacent to the home (2-5') and the service will be located elsewhere most likely a multiple meter assembly with service breakers that feed the disconnects just mentioned.

The metered service pedestals located adjacent to the home will have a grounding electrode and the multiple metered service will have a grounding electrode at it, the disconnect located next to the home will also have a electrode at it,
now being this close to the home does it make any sense to have another ground rod at the trailer that is only 2-5 feet away from this disconnect or service pedestal? What purpose would it or could it serve?
When we met with HUD with the state of Indiana also present many years ago, we discussed this because a local inspector was trying to say we needed a rod at the trailer, both the state and the HUD inspector stated it would serve no purpose and is not required, that the electrode at the disconnect or service equipment which ever is installed close to the trailer serves as the grounding electrode for the trailer connected through the grounding conductor (EGC) run with the feeders to the panel inside.

 

[david]

? the neutral conductors and the equipment grounding bus shall be connected

I am sure you are aware at least around here when these rules where written it was common for most buildings to be supplied by a 3-wire feeder in contrast to the four wire feeder. There seems to be much emphasis in article 550 that the service neutral is to be bonded and the feeder neutral is to be un-bonded.
It seems to me that the referances to 250.32(B) was to insure that the feeder nuetral was un-bonded

 

[hurk27]

Smart in your quote of Mark Cloutier which wasn't a post Mark made in the other forum, but a quote posted by Paul Abernathy in the other forum, who also went on to post his opinion which in post 31 on that site he made an exceptional post as to why the opinion of electrodes being required goes wrong and the fact that many at NFPA also feel they are not needed, and the same reason why as I have pointed out, as they would serve no purpose, this also has another side that if someone were to ever challenged this in a court of law I'm sure you know that as a requirement of law it would be shot down as soon at it was determine that a rod at the trailer would have no usefulness and laws can not just be made because someone thought it was a good idea.

If I remember right Paul is a member here, maybe he will chime in?

I will agree that the NEC is very muddy on this and will leave it at that.

 

[david]

I hate to even ask this question but there has been a lot of debate in this thread because most structures when supplied by feeders would be required to establish a grounding electrode system at the structure. And the general requirements of the code apply unless amended or modify by a specific lets say 500 article

Looking at the language in the scoping provision of article 550.1 since it says this article applies from every thing associated with mobile and manufacture home up to the mobile home service equipment.

Does that language give more muscle to article 550 then the general requirements in other articles in the code?

For instance

Feeder Assembly. The overhead or under-chassis feeder conductors, including the grounding conductor, together with the necessary fittings and equipment or a power-supply cord listed for mobile home use, designed for the purpose of delivering energy from the source of electrical supply to the distribution panelboard within the mobile home.

In contrast to feeder in the general requirements in other articles of the code

So when you say feeder from the distribution panel of a mobile home to the disconnect or service equipment you are talking about something specific to article 550 that does not apply to other feeders not connected to a mobile or manufacture home.

 

[iwire]

why as I have pointed out, as they would serve no purpose, this also has another side that if someone were to ever challenged this in a court of law I'm sure you know that as a requirement of law it would be shot down as soon at it was determine that a rod at the trailer would have no usefulness and laws can not just be made because someone thought it was a good idea.

Hurk, I really have a problem with your assumptions stated above.

How can you question the usefulness of a rod at the trailer when every other separate structure supplied by a feeder requires a GES?

What I am saying is this .......... I have no idea if the rod is useful or not ........ and neither do you if you are honest with yourself.


But if this did have to go to court how could you possibly argue that a GES at mobile home serves no purpose when all other structures require one. What type of magic does a mobile home have to behave differently?

 

[Dennis Alwon]

I think Wayne is saying in general rods are worthless however there is no need for extra rods when you can use the rods at the pole less than 5' away. There is nothing that states the rod must be "X feet" from the structure. ????

 

[david]

So more broadly the term feeder encompasses every thing it takes not just the conductors but all the equipment and fittings it take to get electrical supply from the source to the distribution panel in the manufactured or mobile home

 

[iwire]

I think Wayne is saying in general rods are worthless

But that is (IMPO) an entirely different subject that includes everything from 4000 amp services to a CB radio antenna in the back yard.

however there is no need for extra rods when you can use the rods at the pole less than 5' away. There is nothing that states the rod must be "X feet" from the structure. ????

And how is this suddenly different for a mobile home vs a detached garage just 5' from a home? :?:huh:

The NEC has made clear in the case above I can't use the EGC as a GES bond between the buildings.



Again I will point out this.

I don't know what the NFPA requires for GES at this mobile home, all I do know is that for all other separate structures the NFPA does require a GES.

If they intend to change the things for a mobile home I would really expect some clearer language about it like many other code sections have when one section modifies another.

Could it be a simply omission?

Sure, no doubt.

But an omission is an omission and the words in the NEC now do not say 250.32 is out of the picture.

 

[iwire]

So more broadly the term feeder encompasses every thing it takes not just the conductors but all the equipment and fittings it take to get electrical supply from the source to the distribution panel in the manufactured or mobile home

I am really missing the point you are trying to make.

 

[Dennis Alwon]

And how is this suddenly different for a mobile home vs a detached garage just 5' from a home? :?:huh:

The NEC has made clear in the case above I can't use the EGC as a GES bond between the buildings.

Who said anything about using the egc. I was thinking you would just run the GEC from the trailer back to the rods by the pole.

 

[iwire]

Who said anything about using the egc. I was thinking you would just run the GEC from the trailer back to the rods by the pole.

IMO what you suggest would be 100% compliant, but I don't think anyone has suggested doing that.

I think they are saying a GEC is not required from the trailer directly to any GES at all.

I believe they are saying the EGC in the feeder to the disconnect is all that is required to connect the mobile home to the GES.

 

[david]

I am really missing the point you are trying to make.

The point is this it has been arqued that a feeder is not normanly relied on to provide a path from a structure to a grounding elecrode sytem

Does the term feeder assembly incorporate allowence spacic to mobile and manufactured homes that feeders in other articles normally would not have.

The second point is the scoping provision in atrticle 550 seem to give more muscle to article 550 then the general requirements in other sections of the code

 

[Dennis Alwon]

IMO what you suggest would be 100% compliant, but I don't think anyone has suggested doing that.

I think they are saying a GEC is not required from the trailer directly to any GES at all.

I believe they are saying the EGC in the feeder to the disconnect is all that is required to connect the mobile home to the GES.

If that what this is about then I agree 100% with you. :thumbsup: