mobile home & ground rods

[david]

I don?t know if your clincher is a strike or a curve ball

? Now you can go to 250.32(A) for the electrode requirements.
You could if they where required;

As you posted and high lighted in red
(2) Feeder conductors shall be installed in compliance with
250.32(B).

Note it does not say the feeder conductors shall be installed in compliance with 250.32 it does say 250.32(B) That seems deliberate in leaving 250,32(A) out of the requirement your trying to imply because grounding electrodes are mentioned in 250.32(B) they have to be installed.

I would agree if the rule said shall be incompliance with 250.32 it does not it says 250.32(B)

 

[david]

For the most part 550.33 puts emphasis on the four wire feeder in contrast to what was a common 3 wire feeder to most buildings back when these rules where written special emphasis on an insulated equipment ground. (extra protection against stray voltages).

When you bring the exception into this discussion the reference to 250.32(b) this section seems to be emphasizing the un-bonded neutral more than any thing else

 

[david]

I don?t know if your clincher is a strike or a curve ball

? Now you can go to 250.32(A) for the electrode requirements.
You could if they where required;

As you posted and high lighted in red
(2) Feeder conductors shall be installed in compliance with
250.32(B).

Note it does not say the feeder conductors shall be installed in compliance with 250.32 it does say 250.32(B) That seems deliberate in leaving 250,32(A) out of the requirement your trying to imply because grounding electrodes are mentioned in 250.32(B) they have to be installed.

I would agree if the rule said shall be incompliance with 250.32 it does not it says 250.32(B)

550.32 Service Equipment.
Grounding at the disconnecting means shall be in accordance with 250.32.

Please note 550.32 says in accordance with 250.32
550.33 in compliance with 250.32 (B)

 

[Smart $]

I don’t know if your clincher is a strike or a curve ball

...

For the most part 550.33 puts emphasis on the four wire feeder...

550.32 Service Equipment.
Grounding at the disconnecting means shall be in accordance with 250.32.

Please note 550.32 says in accordance with 250.32
550.33 in compliance with 250.32 (B)

Well, in my understanding of baseball, to go along with the analogy, a curve ball can result in a strike, or a grand slam :slaphead:

You are correct. It says 250.32(B), not 250.32 or 250.32(A)...

However, the simple fact: compliance with 250.32(B) is mandated and you can't connect (or not connect regarding grounded circuit conductor) to a grounding electrode(s), if there is(are) none. You need no more specificity. Read it 100 times if you must... but I assure you, it will not change

 

[hurk27]

I didn't realize that 550 only referenced 250.32(B) Knowing this is that 250.32(B) is not a requirement for a grounding electrode system, it is the requirement for running the EGC with feeders, and "if" there is a grounding electrode system the EGC is what must be used to connect to the electrode system and not the grounded conductor, to use this as a requirement for installing a grounded electrode system is stretching the code.

The service equipment is the first disconnect in the path to the trailer, if more then 30' then you will have another disconnect that serves as the disconnect, then you will have the required disconnect within the trailer usually the main in the panel, but these last two disconnects are not service disconnects they are only required disconnects and are not even required to have OCPDs the only thing that can be considered as a required electrode is the bonding of the frame of the trailer (which is required in the HUD code to be done by the manufacture) I compare this to the requirement of bonding the frame or body of a vehicle mounted generator and serving as an electrode as the same as the bonding of the trailer frame. do we have to install a ground rod for a vehicle mounted generator? Nope, do we have to install a ground rod for a RV? (551) nope, what about a park trailer? (552) nope.

Again I ask how is it that 551 or 552 says nothing that directly relives the grounding electrode requirement of 230.32(A) but yet we don't even question this? is it because they come on wheels? well so does a mobile/manufactured home, does it have a permanent frame, same answer, if you look up the definition of a mobile/manufactured home it will have in its definition a dwelling structure designed to be moved from site to site and many are, again same as a RV or park trailer.

Just because many of these trailers might never get moved should not change the requirement, put it on a permanent foundation so that it can never be moved that could maybe change things but I'm not even sure about that? but I think that the fact that they come from the factory with wheels and axles so that they can be moved is something for us to look at in this discussion.

I don't even see anything a extra ground rod at the trailer would do? what purpose would it serve? if there is one at the last disconnect 2' from the trailer I think it would be worthless even at 30' from the trailer it would do little to nothing but this is my opinion of course

 

[Smart $]

I didn't realize that 550 only referenced 250.32(B) Knowing this is that 250.32(B) is not a requirement for a grounding electrode system, it is the requirement for running the EGC with feeders, and "if" there is a grounding electrode system the EGC is what must be used to connect to the electrode system and not the grounded conductor, to use this as a requirement for installing a grounded electrode system is stretching the code.

I find it amazing how people puts words where there are none. 250.32(B) does not say "if" there is a grounding electrode. It says, in short, " an equipment grounding conductor... shall... be connected to the grounding electrode(s)."

The service equipment is the first disconnect in the path to the trailer, if more then 30' then you will have another disconnect that serves as the disconnect, then you will have the required disconnect within the trailer usually the main in the panel, but these last two disconnects are not service disconnects they are only required disconnects and are not even required to have OCPDs the only thing that can be considered as a required electrode is the bonding of the frame of the trailer (which is required in the HUD code to be done by the manufacture) I compare this to the requirement of bonding the frame or body of a vehicle mounted generator and serving as an electrode as the same as the bonding of the trailer frame. do we have to install a ground rod for a vehicle mounted generator? Nope, do we have to install a ground rod for a RV? (551) nope, what about a park trailer? (552) nope.

Again I ask how is it that 551 or 552 says nothing that directly relives the grounding electrode requirement of 230.32(A) but yet we don't even question this? is it because they come on wheels? well so does a mobile/manufactured home, does it have a permanent frame, same answer, if you look up the definition of a mobile/manufactured home it will have in its definition a dwelling structure designed to be moved from site to site and many are, again same as a RV or park trailer.

Just because many of these trailers might never get moved should not change the requirement, put it on a permanent foundation so that it can never be moved that could maybe change things but I'm not even sure about that? but I think that the fact that they come from the factory with wheels and axles so that they can be moved is something for us to look at in this discussion.

I don't even see anything a extra ground rod at the trailer would do? what purpose would it serve? if there is one at the last disconnect 2' from the trailer I think it would be worthless even at 30' from the trailer it would do little to nothing but this is my opinion of course

While I respect what you think... I also take it for nothing more than what you think. I invite you to submit a proposal, or comment on any related proposal submitted by another.

 

[hurk27]

I find it amazing how people puts words where there are none. 250.32(B) does not say "if" there is a grounding electrode. It says, in short, " an equipment grounding conductor... shall... be connected to the grounding electrode(s)."

So if you have a single circuit to a garage then what grounding electrode are you going to install to meet this requirment? doesnt 250.32(B) still apply?

 

[david]

Well, in my understanding of baseball, to go along with the analogy, a curve ball can result in a strike, or a grand slam :slaphead:

You are correct. It says 250.32(B), not 250.32 or 250.32(A)...

However, the simple fact: compliance with 250.32(B) is mandated and you can't connect (or not connect regarding grounded circuit conductor) to a grounding electrode(s), if there is(are) none. You need no more specificity. Read it 100 times if you must... but I assure you, it will not change

From the hand book
Similar to the provisions of 250.30(A)(3), the requirement in 250.32(B) eliminates the creation of parallel paths for normal neutral current on grounding conductors, metal raceways, metal piping, and other metal structures. In the 1999 and previous editions of the Code, the grounding electrode conductor and equipment grounding conductors were permitted to be connected to the grounded conductor at a separate building or structure. This multiple-location grounding arrangement could provide parallel paths for neutral current along the electrical system and along other continuous metallic piping and mechanical systems as well.

Even the writers of the commentary in he handbook believe the 250.32(b) eliminates parallel paths and that the mandate for grounding electrodes are in 250,32(A)

 

[Smart $]

So if you have a single circuit to a garage then what grounding electrode are you going to install to meet this requirment? doesnt 250.32(B) still apply?

As you well know, 250.32(A) Exception relinquishes the electrode requirement for a single branch circuit. And as you also know, a single branch circuit is not a feeder... and vice versa.

 

[Smart $]

From the hand book
Similar to the provisions of 250.30(A)(3), the requirement in 250.32(B) eliminates the creation of parallel paths for normal neutral current on grounding conductors, metal raceways, metal piping, and other metal structures. In the 1999 and previous editions of the Code, the grounding electrode conductor and equipment grounding conductors were permitted to be connected to the grounded conductor at a separate building or structure. This multiple-location grounding arrangement could provide parallel paths for neutral current along the electrical system and along other continuous metallic piping and mechanical systems as well.


Even the writers of the commentary in he handbook believe the 250.32(b) eliminates parallel paths and that the mandate for grounding electrodes are in 250,32(A)

Goes to assumed intent and thus irrelevant. What the authors think has no more authority on the issue than what Wayne thinks. And for the sake of spelling it out, that is zero authority.

 

[hurk27]

As you well know, 250.32(A) Exception relinquishes the electrode requirement for a single branch circuit. And as you also know, a single branch circuit is not a feeder... and vice versa.

And what does feeder have to do with what 250.32(B) says, I don't see feeder in it? 250.32(B) requires a EGC even if it is feeder or a single circuit branch circuit, it does not define between the two? so if it is saying that the EGC must connect to grounding electrodes, then it has to require it for both or not be requiring it at all? again 250.32(A) is requiring grounding electrodes not (B)

 

[david]

From the manufacture Clayton Homes

Grounding
The home must be properly grounded to protect the occupants. The only safe and approved method of grounding the home is through an electrically-isolated grounding bar in the homes distribution panel board. This grounds all non-current carrying metal parts to the electrical system in the home at a single point. The ground conductor of the power supply feeder cable in turn connects the grounding bar to a good electrical ground back through the power supply system. Therefore , for 120/240 volt service a four wire power supply feeder cable is required.

 

[Smart $]

And what does feeder have to do with what 250.32(B) says, I don't see feeder in it?

Because we are analyzing 250.32(B) as it relates to 550.33, which is titled "Feeder"....???

250.32(B) requires a EGC even if it is feeder or a single circuit branch circuit, it does not define between the two? so if it is saying that the EGC must connect to grounding electrodes, then it has to require it for both or not be requiring it at all? again 250.32(A) is requiring grounding electrodes not (B)

For a single branch circuit to a garage, all of 250.32 applies... no Article 550 involved and not restricted to just 250.32(B). Remember, I'm on the side that is saying all of 250.32 applies to manufactured homes, whether supplied by SE or feeder.

 

[Smart $]

From the manufacture Clayton Homes

Grounding
The home must be properly grounded to protect the occupants. The only safe and approved method of grounding the home is through an electrically-isolated grounding bar in the homes distribution panel board. This grounds all non-current carrying metal parts to the electrical system in the home at a single point. The ground conductor of the power supply feeder cable in turn connects the grounding bar to a good electrical ground back through the power supply system. Therefore , for 120/240 volt service a four wire power supply feeder cable is required.

What's your point??? The statement is accurate, but has nothing to do with a GES being required or not at the structure. A GES is not intended to carry ground-fault current, That is the function of bonding, the EGC, and the grounded conductor on the supply side of the service disconnecting means.

 

[hurk27]

I was trying to show you from your statement in post 106:

" an equipment grounding conductor... shall... be connected to the grounding electrode(s)."

is not a requirement for a grounding electrode, simply as I pointed out the it would conflict with the exception for a single branch circuit in 250.32(A) if it did?

250.32(A) is the place where a GE is required not (B) and 550 does not reference (A)

 

[david]

What's your point??? The statement is accurate, but has nothing to do with a GES being required or not at the structure. A GES is not intended to carry ground-fault current, That is the function of bonding, the EGC, and the grounded conductor on the supply side of the service disconnecting means.

My point any one reading that post would understand what my point is. Even the manufacture says the grounding is connected through the four wire feeder.

They say the only safe way is a one point grounding system from a single point in the distribution panel through the feeder equipment ground to ground.

MCGRAW-HILL?S national electrical code handbook page 1315
The point of connection to the grounding electrode conductor is through the feeder

 

[Smart $]

I was trying to show you from your statement in post 106:


is not a requirement for a grounding electrode, simply as I pointed out the it would conflict with the exception for a single branch circuit in 250.32(A) if it did?

250.32(A) is the place where a GE is required not (B) and 550 does not reference (A)

No. Because 250.32(A) Exception carries over to 250.32(B) in the case of a single branch circuit. Additionally, there is no exception for a feeder.

 

[Smart $]

My point any one reading that post would understand what my point is. Even the manufacture says the grounding is connected through the four wire feeder.

They say the only safe way is a one point grounding system from a single point in the distribution panel through the feeder equipment ground to ground.

MCGRAW-HILL?S national electrical code handbook page 1315
The point of connection to the grounding electrode conductor is through the feeder

There is more than one type of and purpose for grounding. Grounding for fault current is but one.

 

[david]

550.32 when talking about the feeder from the service structure to the disconnect structure references 250.32
Feeder from one structure to a second structure in accordance with 250.32

550.33 talking about the feeder from the disconnect structure to the mobile home structure in compliance with 250,32(B) feeder from the second structure to the third structure in accordance with 250,32(B)
you are arguing they both mean the same thing I say they do not

I can tell you what size grounding electrode conductor is required in 550,32
I could not tell you that in 550.33

250.32(E) is not referenced in 550.33 neither is 250.32(A)

 

[Smart $]

550.32 when talking about the feeder from the service structure to the disconnect structure references 250.32
Feeder from one structure to a second structure in accordance with 250.32

Actually, 550.32 is titled "Service Equipment" and mentions "feeder" only one time. That is in 550.32(C) regarding provisions for connection of a mobile home feeder assembly by permanent wiring method.... because mobile home service equipment must be rated not less than 100A, yet power receptacles for mobile vehicles are not rated greater than 50A.

550.33 talking about the feeder from the disconnect structure to the mobile home structure in compliance with 250,32(B) feeder from the second structure to the third structure in accordance with 250,32(B)
you are arguing they both mean the same thing I say they do not

That is one interpretation. If you consider that Part III is titled "Services and Feeders" then read 550.33(B), you will see it is referring to feeders supplying power to the mobile or manufactured home.

I can tell you what size grounding electrode conductor is required in 550,32
I could not tell you that in 550.33

250.32(E) is not referenced in 550.33 neither is 250.32(A)

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: