mobile home & ground rods

[david]

Ok I am going to ask a question and please do not take this thread into a debate about swimming pools

Please not in my example am going to note a detached garage feed from a existing feeder from a single family dwelling

The garage Is existing and is completely code compliant. It has two ground rods connected to the service rated distribution panel

The garage is closes to the swimming pool i need to run a feeder to pool equipment I want to determine if that feeder can be run from the garage or do I have to run it from the service in the dwelling.
The garage supply is 240/120 volts

I need a feeder I am not interested in supplying the pool with branch circuits

(2) Separate Buildings. A feeder to a separate building or structure shall be permitted to supply swimming pool equipment branch circuits, or feeders supplying swimming pool equipment branch circuits, if the grounding arrangements in the separate building meet the requirements in 250.32(B). Where installed in other than existing feeders covered in 680.25(A), Exception, a separate equipment grounding conductor shall be an insulated conductor.

The reference to 250.32 (B) tells me to look at the feeder how is it connected if it is a four wire feeder and connected correctly I can run my feeder to the swimming pool equipment.

If it is not connected correctly it does not meet the requirements of 250.32 (B) I cannot supply my swimming pool from this panel in the garage

If on the other hand I walk up to the existing garage and it is a three wire URD feeder in PVC it doe not meet the requirements in
250.32 (B)
I cannot supply my swimming pool equipment with a feeder from this garage.

When I get back I am going to contrast this to the feeder requirements
In 547.9 (C) in an attempt to illustrate the difference in referencing 250.32(B) in contrast to referencing 250.32

I believe the difference is deliberate and means two different things

ARTICLE 547 Agricultural Buildings
B) Service Disconnecting Means and Overcurrent Protection at the Building(s) or Structure(s). Where the service disconnecting means and overcurrent protection are located at the building(s) or structure(s), the requirements of 547.9(B)(1) through (B)(3) shall apply.

(3) Grounding and Bonding. For each building or structure, grounding and bonding of the supply conductors shall be in accordance with the requirements of 250.32, and the following conditions shall be met:

(C) Service Disconnecting Means and Overcurrent Protection at the Distribution Point. Where the service disconnecting means and overcurrent protection for each set of feeder conductors are located at the distribution point, feeders to building(s) or structure(s) shall meet the requirements of 250.32 and Article 225, Parts I and II.

 

[david]

ARTICLE 547 Agricultural Buildings
B) Service Disconnecting Means and Overcurrent Protection at the Building(s) or Structure(s). Where the service disconnecting means and overcurrent protection are located at the building(s) or structure(s), the requirements of 547.9(B)(1) through (B)(3) shall apply.

(3) Grounding and Bonding. For each building or structure, grounding and bonding of the supply conductors shall be in accordance with the requirements of 250.32, and the following conditions shall be met:

(C) Service Disconnecting Means and Overcurrent Protection at the Distribution Point. Where the service disconnecting means and overcurrent protection for each set of feeder conductors are located at the distribution point, feeders to building(s) or structure(s) shall meet the requirements of 250.32 and Article 225, Parts I and II.

A accidentally save the reply before I was done.

250.32 (B)
For a grounded system at the separate building or structure, an equipment grounding conductor as described in 250.118 shall be ………………….Any installed grounded conductor shall not be connected to the equipment grounding conductor or to the grounding electrode(s).

250.32 (B)
Is not focused on a ground rods existence or non existence,
It I focused on both the Equipment ground and the neutral connections

Unless I missed it 250.32(B) is not referenced one time in this article.

The very fact that both 250,32 and 250,32(B) are mentioned are telling us that something different is being said in article 550

 

[Smart $]

Let me say this one more time, I agree that by Article 100 the service pole and the home are two different things call it structure if you like, I don?t object.

Okay.

by definition both are the same see definitions in 550. Both can be hard wired.

I admit my use of the terms have been tainted by my personal definitions. What I personally consider a mobile home would fall under the article for Park Trailers. From this point forward I will attempt to use the terms as defined by Code...

However, by definition, a mobile home is not exactly the same as a manufactured home. It is self-evident simply in that each has its own differently-worded defintition. What the Code does say is:

For the purpose of this Code and unless otherwise indicated, the term mobile home includes manufactured homes.

As such, a manufactured home must meet all Article 550 provisions regarding a mobile home. Only those provisions specifically indicating they apply to a manufactured home do not apply to both.

WOW! I didn?t know that any current flowed into earth. I have always though that the earth connection was for lightning, power surges, unintentional contact with higher voltage line and all them other things outlined in 250.4(A)(1)

Latter sentence exactly. I did not say the cause for the current. But if no current ever flowed into (or from) earth, there would be no purpose for any grounding electrode system.

Neither is a hard wired mobile home

Well now that I'm using Code definitions, I have to retract any distinction I attempted to make earlier.

Look at Table 250.3

I don't see your point regarding other Chapter 5 Articles being listed in Table 250.3. What does that have to do with Article 550 installations? However, in looking at Table 250.3 I did note it is titled: Additional Grounding and Bonding Requirements. It does not say amended requirements.

 

[Smart $]

A accidentally save the reply before I was done.

250.32 (B)
For a grounded system at the separate building or structure, an equipment grounding conductor as described in 250.118 shall be ………………….Any installed grounded conductor shall not be connected to the equipment grounding conductor or to the grounding electrode(s).

250.32 (B)
Is not focused on a ground rods existence or non existence,
It I focused on both the Equipment ground and the neutral connections

Unless I missed it 250.32(B) is not referenced one time in this article.

The very fact that both 250,32 and 250,32(B) are mentioned are telling us that something different is being said in article 550

I do see your point... and perhaps the intent is that no GES is required at a feeder supplied m-home. However, until I see an explicit provision which says no GES is required, I cannot cede my position. I would even accept a CMP statement on proposal or comment as good enough. But until such time...

 

[jwelectric]

I don't see your point regarding other Chapter 5 Articles being listed in Table 250.3. What does that have to do with Article 550 installations? However, in looking at Table 250.3 I did note it is titled: Additional Grounding and Bonding Requirements. It does not say amended requirements.

250.3 Application of Other Articles. For other articles applying to particular cases of installation of conductors and equipment, grounding and bonding requirements are identified in Table 250.3 that are in addition to, or modifications of, those of this article.

 

[Smart $]

250.3 Application of Other Articles. For other articles applying to particular cases of installation of conductors and equipment, grounding and bonding requirements are identified in Table 250.3 that are in addition to, or modifications of, those of this article.

Yes, I read the section text also. Nevertheless, that's the whole problem. Nothing in Article 550 explicitly modifies the requirements of 250.32. The 550.33(A)(2) reference to only 230.32(B) rather than 230.32 at best only implies no GES at the home is required.

 

[jwelectric]

Yes, I read the section text also. Nevertheless, that's the whole problem. Nothing in Article 550 explicitly modifies the requirements of 250.32. The 550.33(A)(2) reference to only 230.32(B) rather than 230.32 at best only implies no GES at the home is required.

So if there is no grounding electrode then there is no need for a grounding electrode conductor

So now what is the debate about?

 

[Smart $]

So if there is no grounding electrode then there is no need for a grounding electrode conductor

How the heck did you get that out of my post? That's neither what I said nor meant.

So now what is the debate about?

Still required or not GES at home. No change.

 

[jwelectric]

If you truly believe that a GES is required at the trailer please tell me how to connect and where to connect it at. Use code references please

 

[pfalcon]

No, it does not use the at. It uses the word to. That is, adjacent to.

I'm talking about adjacent not to or at, as used in article 550. In the context of 550 it's used as a fancy word for at, present, next to, in the proximite vicinity of.

Also note you are recognizing the service and the home as two structures.

You can argue with iwire about whether it's one structure or two. I surrended that long ago. So yes, I'm treating them as two structures.

The word adjacent means "next to", but the distance is relative and not defined by the NEC. Where the NEC requires the distance to be minimal, it uses the combined term: immediately adjacent. As an example of how differing the distance can be, look at 250.184(C) where the adjacent distance is up to 1300ft.

In this context adjacent refers to the next logical unit. Welcome to English usage. Context defines the meaning.

That's a fair point, but you confirmed the likely more permanant residency... which was my point.

Missed 553. As for 500, 510, and 550, they were not in the list mentioned by Mike.

But you are considering the service and home as one building or structure. I am not.

Wait! Let me scroll back up. One? Two? I feel like Paul Revere. TWO, count em with me, TWO.
Where does 250.50 care about how many structures the GES serves? If there are two electrodes present at the service - bond them. If there are two electrodes present at the home - bond them. The article doesn't discriminate between whether you drove the electrode for the service or for the home. Two rods are present - bond them.

Again, this is a consequence of you considering the two structures as one. But even as separate structures, there is nothing which prevents you from bonding the electrodes together AFAIK.

Discussed above

 

[don_resqcapt19]

If you truly believe that a GES is required at the trailer please tell me how to connect and where to connect it at. Use code references please

It would connect to the panel EGC terminal bar just like it would at any second building. As far as if it is required, I am not so sure. I thought that 250.32 applied here, but your comments and others have me re-thinking about that.

 

[renosteinke]

"It would connect to the panel ...."

That's the problem. There is no way to access the panel, to run such a wire- not without causing permanent damage to the trailer. Even with the wall completely open, there is no straight shot to the underside of the trailer - any wires you route have a convoluted path through the various framing members. The trailers are clearly made 'complete.'

(Clarification: I am thinking back to a trailer re-wire that had the panel on an outside wall. Another trailer job, where the panel was on an interior wall, might not have been such a challenge.)

In any event, one would think the trailers would come equipped with a lug, a pigtail, or even a piece of smurf tube to facilitate connection of the GEC to the panel. Alas, they don't.

 

[Smart $]

I'm talking about adjacent not to or at, as used in article 550. In the context of 550 it's used as a fancy word for at, present, next to, in the proximite vicinity of

...

In this context adjacent refers to the next logical unit. Welcome to English usage. Context defines the meaning.

Because the Code does not define adjacent, I believe Webster's Collegiate Dictionary is the official reference:

ad?ja?cent

Pronunciation:	ə-'jā-sənt
Function:	adjective
Etymology:	Middle English, from Anglo-French or Latin; Anglo-French, ajesaunt, from Latin adjacent-, adjacens, present participle of adjacēre to lie near, from ad- + jacēre to lie; akin to Latin jacere to throw ― more at JET
Date:	15th century

1 a : not distant : NEARBY <the city and adjacent suburbs> b : having a common endpoint or border <adjacent lots> <adjacent sides of a triangle> c : immediately preceding or following
2 of two angles : having the vertex and one side in common
–ad?ja?cent?ly adverb
synonyms ADJACENT, ADJOINING, CONTIGUOUS, JUXTAPOSED mean being in close proximity. ADJACENT may or may not imply contact but always implies absence of anything of the same kind in between <a house with an adjacent garage>. ADJOINING definitely implies meeting and touching at some point or line <had adjoining rooms at the hotel>. CONTIGUOUS implies having contact on all or most of one side <offices in all 48 contiguous states>. JUXTAPOSED means placed side by side especially so as to permit comparison and contrast <a skyscraper juxtaposed to a church>.

? 2005 Merriam-Webster, Incorporated

Note the differentiation on synonyms even uses a two building example.

Wait! Let me scroll back up. One? Two? I feel like Paul Revere. TWO, count em with me, TWO.
Where does 250.50 care about how many structures the GES serves? If there are two electrodes present at the service - bond them. If there are two electrodes present at the home - bond them. The article doesn't discriminate between whether you drove the electrode for the service or for the home. Two rods are present - bond them.

For immediately adjacent reference:

250.50 Grounding Electrode System. All grounding electrodes
as described in 250.52(A)(1) through (A)(7) that are
present at each building or structure served shall be bonded
together to form the grounding electrode system.

Note the requirement is "present at each building or structure served" ... not "present at all buildings and structures served". We have both the word each and non-plural usage of building and structure. Nevertheless, I can see how this can be construed, but I believe my interpretation is both the intent and consensus.

 

[Smart $]

"It would connect to the panel ...."

That's the problem. There is no way to access the panel, to run such a wire- not without causing permanent damage to the trailer. Even with the wall completely open, there is no straight shot to the underside of the trailer - any wires you route have a convoluted path through the various framing members. The trailers are clearly made 'complete.'

(Clarification: I am thinking back to a trailer re-wire that had the panel on an outside wall. Another trailer job, where the panel was on an interior wall, might not have been such a challenge.)

In any event, one would think the trailers would come equipped with a lug, a pigtail, or even a piece of smurf tube to facilitate connection of the GEC to the panel. Alas, they don't.

How do you get the outside feeder to the panel?

 

[hurk27]

How do you get the outside feeder to the panel?

3280.803(k)(2) An approved raceway from the disconnecting means in the manufactured home to the underside of the manufactured home with provisions for the attachment of a suitable junction box or fitting to the raceway on the underside of the manufactured home. The manufacturer shall provide in his written installation instructions, the proper feeder conductor sizes for the raceway and the size of the junction box to be used; or

Been required by HUD for a few years now, the manufacture has to install this pipe.
Almost all the ones we wire that was manufactured in a past 10 years has had this pipe, and some even has another 3/4"-1" stubbed down for a way to feed the AC unit or post lamp pole.

As far as the GEC goes I don't see anything prohibiting it to connect to the frame as there is already a frame bond from the panel sized for the largest feeder that can be installed, In most cases it is a #6, While I don't think a GES is needed and here in Indiana we don't have to install one as per state, but I agree with others it's not very clear in the NEC one way or the other, a proposal would clear this up.

 

[pfalcon]

Because the Code does not define adjacent, I believe Webster's Collegiate Dictionary is the official reference:

​

Note the differentiation on synonyms even uses a two building example.

So why do you ignore 1a not distant : NEARBY for adjacent when

pres?ent adj \ˈpre-zənt\
Definition of PRESENT
1: now existing or in progress
2a : being in view or at hand b : existing in something mentioned or under consideration
3: constituting the one actually involved, at hand, or being considered
4: of, relating to, or constituting a verb tense that is expressive of present time or the time of speaking
5obsolete : attentive
6archaic : instant, immediate

from your own expert source PRESENT only means 2a : being in view or at hand?

For immediately adjacent reference:

​

Note the requirement is "present at each building or structure served" ... not "present at all buildings and structures served". We have both the word each and non-plural usage of building and structure. Nevertheless, I can see how this can be construed, but I believe my interpretation is both the intent and consensus.

Yes, it's singular. You have to identify all the grounding electrode systems present at any singular building or structure. Then bond them together.
The GES for the service structure is present, nearby, at hand, in view, adjacent, and not distant to the mobile home (singular).
The GES for the mobile home is also present, nearby, at hand, in view, adjacent, and not distant to the service structure (singular).
Therefore as the Service GES and MH GES are present at the mobile home (singular) they must be bonded together.
Therefore as the Service GES and MH GES are present at the service structure (singular) they must be bonded together.

Otherwise you generate a potential shock hazard if someone contacts both structures at the same time. We enforce this rigidly in industry. All our machine tools are bonded to the building steel as a common GES.

It may be correct, to which I disagree, that a rod must be driven to a hard-wire MH. But if so then it better be bonded to the service GES. Both the service GES and the MH GES could be thoroughly grounded but isolated from each other; and in arms reach.

 

[pfalcon]

"present at each building or structure served"

Frankly I think you're letting you're personal bias re-write the code to mean dedicated to each building or structure served instead of simply present. IMO.

 

[Smart $]

Been required by HUD for a few years now, the manufacture has to install this pipe.
Almost all the ones we wire that was manufactured in a past 10 years has had this pipe, and some even has another 3/4"-1" stubbed down for a way to feed the AC unit or post lamp pole.

I knew this. The question was somewhat rhetorical. What it was leading to is, I don't believe there is any restriction prohibiting a GEC run in this conduit with the feeder. The CFR section you cited even requires provisions for junction box attachment.

As far as the GEC goes I don't see anything prohibiting it to connect to the frame as there is already a frame bond from the panel sized for the largest feeder that can be installed, In most cases it is a #6, While I don't think a GES is needed and here in Indiana we don't have to install one as per state, but I agree with others it's not very clear in the NEC one way or the other, a proposal would clear this up.

While most would think connecting a GEC to the frame would suffice, it would not be compliant. GEC must be continuous and is required to connect at the same bus or terminal as the feeder EGC termination in the disconnecting means.

I agree, a proposal would most certainly clear it up!

 

[Smart $]

So why do you ignore 1a not distant : NEARBY for adjacent when

I am not ignoring it. You have it covered, so I am contrasting your position.

from your own expert source PRESENT only means 2a : being in view or at hand?



Yes, it's singular. You have to identify all the grounding electrode systems present at any singular building or structure. Then bond them together.
The GES for the service structure is present, nearby, at hand, in view, adjacent, and not distant to the mobile home (singular).
The GES for the mobile home is also present, nearby, at hand, in view, adjacent, and not distant to the service structure (singular).
Therefore as the Service GES and MH GES are present at the mobile home (singular) they must be bonded together.
Therefore as the Service GES and MH GES are present at the service structure (singular) they must be bonded together.

Otherwise you generate a potential shock hazard if someone contacts both structures at the same time. We enforce this rigidly in industry. All our machine tools are bonded to the building steel as a common GES.

It may be correct, to which I disagree, that a rod must be driven to a hard-wire MH. But if so then it better be bonded to the service GES. Both the service GES and the MH GES could be thoroughly grounded but isolated from each other; and in arms reach.

The connection of separate GES's is made through the feeder EGC. A bonding jumper would just parallel that pathway.

I am not saying you can't install a bonding jumper... just saying it is not required.

Frankly I think you're letting you're personal bias re-write the code to mean dedicated to each building or structure served instead of simply present. IMO.

You are certainly entitled to your own opinion, but the the truth is no, I do not believe the electrodes or GES's must be dedicated to each building or structure. I've been involved with grounding grids which interconnect all buildings and structures on premises, including some very large industrial facilities. All I am saying is that a bonding jumper between each building or structure GES is not required. The application of present is subjective and ambiguous. In a real world installation, the distance (or project speciifcations) would probably determine whether or not I would install a bonding jumper.

 

[pfalcon]

The connection of separate GES's is made through the feeder EGC. A bonding jumper would just parallel that pathway.
I am not saying you can't install a bonding jumper... just saying it is not required.

If the EGC can provide bonding then the mobile home is bonded to the GES for the service. Therefore the mobile home structure is bonded to a GES service that is present at the mobile home. That fulfills the requirement for a GES at the mobile home. That would also make the EGC the GEC for the mobile home.

... I do not believe the electrodes or GES's must be dedicated to each building or structure.

... All I am saying is that a bonding jumper between each building or structure GES is not required.

250.50 only requires bonding multiple GES together when they are present at a common building. But when multiple GES are present at a building they must, per 250.50, be bonded together.

The application of present is subjective and ambiguous. In a real world installation, the distance (or project speciifcations) would probably determine whether or not I would install a bonding jumper.

I agree - present and adjacent are both subjective until defined. 550 makes the definition 30 ft. Therefore it's no longer subjective.

Undoubtedly 250.50 was meant for application to large buildings where multiple rods might be established for various reasons. But it says what it says. All GES present at a structure get bonded together. And 550 sets that distance at 30 ft between the service and the mobile home. Therefore a rod driven at the service would of necessity be bonded to a rod driven at the mobile home. And that means running a bond or using the EGC as a GEC for the home. But if the EGC can be used then we're already done by using the original rod so the second is not required.

And you only thought your head was spinning before