mobile home & ground rods

[Smart $]

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.

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.

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

I'll agree 550 places a distance limitation on location, but it defines neither adjacent or present. The word adjacent is used regarding several other issues in 550 with no limitation on distance, yet in those instances I take it to mean "as close as practicable", not up to 30 ft away.

I also cannot subscribe to the premise that anything adjacent is also present.

As for required bonding, first read 250.4 with emphasis on bonding requirements, then see 250.90, wherein note "where necessary". Then go to 250.102(D) for the required size of a bonding jumper on the load side of the service disconnecting means, should one be necessary. A properly sized and connected EGC satisfies general bonding requirements, so a bonding jumper is not necessary. Therefore, it is inappropriate to say "using the EGC as a GEC", although IMO this would be an accurate statement if there was no GES at the MH; also prohibited in 2011 NEC.

 

[david]

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.

• (550.1 Scope.)

The requirements of article 550 stop at the connection to the service entrance conductors

• (550.32 Service Equipment.
• (B) Manufactured Home Service Equipment.
• (2) The installation of the service shall comply with Part I through Part VII of Article 230. )

The general requirements of article 230 dictate the service requirements No matter where the service equipment is located. when a manufactured home is supplied by a feeder assembly by the scoping provisions of article 550.1 article 550 never took control over the service equipment
And as far as manufactured home goes 550.32 (B) (2) by specific reference included parts I through VII of article 230 when the service equipment is on or in a manufactured home

• 550.16
• C) Bonding of Non–Current-Carrying Metal Parts.
• Exposed Non–Current-Carrying Metal Parts. All exposed non–current-carrying metal parts that may become energized shall be effectively bonded to the grounding terminal or enclosure of the distribution panelboard. A bonding conductor shall be connected between the distribution panelboard and accessible terminal on the chassis.
• (3) Metallic Piping and Ducts. Metallic gas, water, and waste pipes and metallic air-circulating ducts shall be considered bonded if they are connected to the terminal on the chassis [see 550.16(C)(1)] by clamps, solderless connectors, or by suitable grounding-type straps.

Article 550 is clear that you can use the metal chassis of a mobile /manufactured Home for bonding Non-Current caring parts.

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

Article 550 by specific reference mandates the Parts I through V of 250 as the bonding and grounding requirements for services attached to or services in manufactured homes
I do agree that nothing in article 550 would prevent you from bonding a ground rod to the metal chassis.

• 250.50 Grounding Electrode System.
• (2) Metal Frame of the Building or Structure. The metal frame of the building or structure that is connected to the earth by any of the following methods:
• (3) Bonding the structural metal frame to one or more of the grounding electrodes as defined in 250.52(A)(5) or (A)(7) that comply with 250.56

But if you are implying you are connecting a ground rod( as a grounding electrode) to the service neutral by bonding it to the metal chassis we differ there. At best by bonding the metal chassis to a ground rod you may be effectively grounding the metal structural steel, there by qualifying it (the metal structural steel) its’ self as a grounding electrode

• 550.32(B)(3) Means shall be provided for the connection of a grounding electrode conductor to the service equipment and routing it outside the structure.

Any time a grounding electrode conductor is instructed to be installed to manufactured homes service equipment the manufacture will provide a means to rout it out side of the structure.

 

[david]

? (F) Mounting Height. Outdoor mobile home disconnecting means shall be installed so the bottom of the enclosure containing the disconnecting means is not less than 600 mm (2 ft) above finished grade or working platform. The disconnecting means shall be installed so that the center of the grip of the operating handle, when in the highest position, is not more than 2.0 m (6 ft 7 in.) above the finished grade or working platform.

I would have in the past made note if the bottom of the service enclosure was closer than 2ft above finished grade.
But I did not apply the scoping provisions of 550.1 correctly. 1 service equipment. 2. Outside disconnect 3. Mobile home main distribution panel.
The language in (f) though I applied it to mobile home service equipment only speaks to the mobile home Outside disconnect, not the service equipment. The service equipment is installed according to the general requirements of article 230.

 

[Smart $]

(F) ...

The language in (f) though I applied it to mobile home service equipment only speaks to the mobile home Outside disconnect, not the service equipment. The service equipment is installed according to the general requirements of article 230.

Umm... (F) is a subsection of 550.32 Service Equipment. When (F) mentions 'disconnecting means', it is the service disconnecting means. It covers all mobile and manufactured home's service disconnecting means except manufactured homes where service equipment is inside.

Having said that may make one wonder about pedestals...

 

[iwire]

264 posts, issues as diverse as the gravitational force of the moon to the popularity of Justin Bieber have been brought forward but still in my opinion no one has been able to show how 250.32 has been modified in a way that the NFPAs own manual of style requires.

 

[david]

Umm... (F) is a subsection of 550.32 Service Equipment. When (F) mentions 'disconnecting means', it is the service disconnecting means. It covers all mobile and manufactured home's service disconnecting means except manufactured homes where service equipment is inside.

Having said that may make one wonder about pedestals...

• (D) Additional Outside Electrical Equipment. Means for connecting a mobile home accessory building or structure or additional electrical equipment located outside a mobile home by a fixed wiring method shall be provided in either the mobile home service equipment or the local external disconnecting means permitted in 550.32(A).
When (F) mentions 'disconnecting means', it is the service disconnecting means, you may have met to say it includes the service disconnecting means. Your statement leaves out the mandated disconnect required to be located within 30 ft of the mobile home which clearly is not service equipment.
The only thing addressed in 550 is the location of the service equipment. And the location is not even a requirement but a design choice. All the requirements are applied in relationship to where the manufactured home service equipment is located. Again 550.1 says the scope ends at the connection of the service entrance conductors.
So you have a permissive rule when it comes to service equipment location. If you choice to locate your service equipment with in 30 ft of a manufactured home and do not provide for additional outside electrical equipment that would be fine.
You would however be required to provide a disconnect even if it is right beside the service disconnect that would provide for additional outside equipment.
• (E) Additional Receptacles. Additional receptacles shall be permitted for connection of electrical equipment located outside the mobile home, and all such 125-volt, single-phase, 15- and 20-ampere receptacles shall be protected by a listed ground-fault circuit interrupter.
(E) is a subsection of 550.32 Service Equipment By your reasoning these additional permitted rec. have to be service equipment. They may be supplied from the service equipment or they may be supplied from the local disconnect they certainly are not service equipment
How you install the service equipment is not controlled directly by article 550 this article sends you to article 230 no matter where the service equipment is located. Depending on the location of the service equipment there are a whole lot of article 550 mandated rules surrounding service equipment.

 

[renosteinke]

"How do you get the feeder to the panel?"

You don't. The trailer comes with a nice, long pigtail from the panel. The electrician gets to connect to that pigtail.

 

[pfalcon]

I'll agree 550 places a distance limitation on location, but it defines neither adjacent or present. The word adjacent is used regarding several other issues in 550 with no limitation on distance, yet in those instances I take it to mean "as close as practicable", not up to 30 ft away.

I also cannot subscribe to the premise that anything adjacent is also present.

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.

Just exactly how much better a definition are you looking for? Short of moving it into the ".2" section it's better defined than most terms that are in a ".2" section. I'll remind you that you went to Webster for an official definition and the above section fits both the definitions for being adjacent and being present. It is "at hand, in view, nearby". Plus it gives a physical, real world, measurable metric for determining adjacent/present. Seriously, how much better a definition do you want? Cause I can't find a better one in 250 or anywhere else in the NEC for what present means. If you can't determine a metric for present then you can't hold anyone to article 250's present. Which means you can't demand any additional GES for the home because you can't determine if a new ground rod is present at the home even if you put it under the home. Pick a meaning for present or surrender this line of argument.

As for required bonding, first read 250.4 with emphasis on bonding requirements, then see 250.90, wherein note "where necessary". Then go to 250.102(D) for the required size of a bonding jumper on the load side of the service disconnecting means, should one be necessary. A properly sized and connected EGC satisfies general bonding requirements, so a bonding jumper is not necessary.

Are we just spamming article numbers here? 250.4 defines a good bond not whether it's present or not. 250.90 certainly says where necessary but we're discussing where required. 250.102(D) discusses sizing but we all agree everything needs to be sized correctly so where does this come in?

Therefore, it is inappropriate to say "using the EGC as a GEC", although IMO this would be an accurate statement if there was no GES at the MH; also prohibited in 2011 NEC.

And I contend that 550.32(A) gives a practical, measurable, defined distance for whether a GES is present at the mobile home.

264 posts, issues as diverse as the gravitational force of the moon to the popularity of Justin Bieber have been brought forward but still in my opinion no one has been able to show how 250.32 has been modified in a way that the NFPAs own manual of style requires.

Better start jumpin in again iwire. I'm not arguing that 250.32 is not in force. But neither you nor Smart$ have proven that the mobile home requires a separate, unique, dedicated GES when there is already one present at the mobile home. Further, since driving a second ground rod necessitates driving it within the bounds of an existing GES then 250.50 requires that you bond them together a create a single GES again. Feel free to make a whole inverted copper fence if you like but make sure you comply with 250.50 and bond them all together to form a single GES. So in the end, you can't have a new GES for the mobile home by driving a new rod, you can only expand the existing one for the service.

I appreciate this thread. I normally focus on inside industrial applications and never residential. You and Smart$ have got me looking hard at the GES requirements and helped me understand them far beyond what I did. Thanks to both of you.

 

[Smart $]

you may have met to say it includes the service disconnecting means. Your statement leaves out the mandated disconnect required to be located within 30 ft of the mobile home which clearly is not service equipment.

Let me restate... (F) applies to the outside mobile home disconnecting means. While (D) specifically references the disconnecting means required when service equipment is located elsewhere on premises, (F) does not. Perhaps an oversight. However, I would not hesitate to apply this to all outside disconnecting means.

The only thing addressed in 550 is the location of the service equipment. And the location is not even a requirement but a design choice. All the requirements are applied in relationship to where the manufactured home service equipment is located. Again 550.1 says the scope ends at the connection of the service entrance conductors.

Come again??? Service equipment is not the only thing addressed in 550. As for 550.1 scope ending at SEC's, that would be true mobile home park SEC's. We have to take 550.30 for a poco service over 240 volts into consideration.

So you have a permissive rule when it comes to service equipment location. If you choice to locate your service equipment with in 30 ft of a manufactured home and do not provide for additional outside electrical equipment that would be fine. You would however be required to provide a disconnect even if it is right beside the service disconnect that would provide for additional outside equipment.

If you are referring to 550.32(D) Additional Outside Electrical Equipment, no, you cannot install a disconnecting means for such right beside the outside mobile home disconnecting means. The requirement says these additional equipment [dis]connecting means must be located in the outside mobile home disconnecting means [enclosure].

(E) is a subsection of 550.32 Service Equipment By your reasoning these additional permitted rec. have to be service equipment. They may be supplied from the service equipment or they may be supplied from the local disconnect they certainly are not service equipment.

(E) is regarding those receptacles which are integral with the outside mobile home disconecting means [enclosure].

 

[pfalcon]

So you have a permissive rule when it comes to service equipment location. If you choice to locate your service equipment with in 30 ft of a manufactured home and do not provide for additional outside electrical equipment that would be fine.
You would however be required to provide a disconnect even if it is right beside the service disconnect that would provide for additional outside equipment.

If you are referring to 550.32(D) Additional Outside Electrical Equipment, no, you cannot install a disconnecting means for such right beside the outside mobile home disconnecting means. The requirement says these additional equipment [dis]connecting means must be located in the outside mobile home disconnecting means [enclosure].

Service Disconnect < 30 ft --- Service Disconnect >30' with second Disconnect < 30 ft.

Since virtually all our discussions are about the load side of the disconnect < 30 ft for either installation, how about we forget about the optional install and just remember it's there.

... shall be provided in either the mobile home service equipment or the local external disconnecting means permitted in 550.32(A).

Gotta go with Smart $ on this one. Adding a disconnect for outside equipment is above and beyond code requirement. Add one for the outside equipment and you still have to connect it to the MH disconnect. You might do this for service convenience but I don't see it as required.

 

[Smart $]

Just exactly how much better a definition are you looking for? Short of moving it into the ".2" section it's better defined than most terms that are in a ".2" section. I'll remind you that you went to Webster for an official definition and the above section fits both the definitions for being adjacent and being present. It is "at hand, in view, nearby". Plus it gives a physical, real world, measurable metric for determining adjacent/present. Seriously, how much better a definition do you want? Cause I can't find a better one in 250 or anywhere else in the NEC for what present means. If you can't determine a metric for present then you can't hold anyone to article 250's present. Which means you can't demand any additional GES for the home because you can't determine if a new ground rod is present at the home even if you put it under the home. Pick a meaning for present or surrender this line of argument.

Well, first, your posted definition is Webster's, but it appears that it is not from the Collegiate edition...

³pres?ent

Pronunciation:	'pre-zənt
Function:	adjective
Etymology:	Middle English, from Anglo-French, from Latin praesent-, praesens, from present participle of praeesse to be before one, from prae- pre- + esse to be ― more at IS
Date:	14th century

1 : now existing or in progress
2 a : 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
5 obsolete : ATTENTIVE
6 archaic : INSTANT, IMMEDIATE
–pres?ent?ness noun
? 2005 Merriam-Webster, Incorporated

I have highlighted the meanings I consider applicable. IMO for a grounding electrode to be present, it must be within the footprint of the building or structure (meaning 2b), or within arms span (building/structure at [one] hand, electrode at [other] hand; meaning 2a as highlighted). I consider being in view as way too ambiguous because on a clear day "I can see for miles and miles..." :happyyes:

Are we just spamming article numbers here? 250.4 defines a good bond not whether it's present or not. 250.90 certainly says where necessary but we're discussing where required. 250.102(D) discusses sizing but we all agree everything needs to be sized correctly so where does this come in?

Let's just say we've made our opinions known. Mine remains unchanged. So you either agree, or agree to disagree... hmy:

And I contend that 550.32(A) gives a practical, measurable, defined distance for whether a GES is present at the mobile home.

So noted... but again, my opinion remains unchanged.

 

[Smart $]

264 posts, issues as diverse as the gravitational force of the moon to the popularity of Justin Bieber have been brought forward but still in my opinion no one has been able to show how 250.32 has been modified in a way that the NFPAs own manual of style requires.

I'm not trying to and will second that opinion :happyyes:

 

[pfalcon]

Well, first, your posted definition is Webster's, but it appears that it is not from the Collegiate edition...

:lol: Yes, I didn't have your specific edition at hand. But if you have to split hairs by citing which edition to use to achieve your position then your position is weak.

I have highlighted the meanings I consider applicable. IMO for a grounding electrode to be present, it must be within the footprint of the building or structure (meaning 2b), or within arms span (building/structure at [one] hand, electrode at [other] hand; meaning 2a as highlighted). I consider being in view as way too ambiguous because on a clear day "I can see for miles and miles..." :happyyes:

We already agreed that present and adjacent are way too ambiguous without further definition. Webster isn't going to improve that. I've contended that 550 establishes what's at hand as 30 ft. If I were to apply your definition of being within the footprint of the structure then there are only rare service drops that meet code. Most of the rods are located inches outside or more. And if we're talking about arms length then how long are your arms? What if you get an inspector without arms? And does Wilt Chamberlain get an easier pass on inspection?

Since your definition for present is so fuzzy then how can you oppose mine, or anyone else's definition for that matter. At least I have a paragraph in the code to stab my finger at.

Let's just say we've made our opinions known. Mine remains unchanged. So you either agree, or agree to disagree... hmy:

I agree you're wrong :angel:

So noted... but again, my opinion remains unchanged.

But it's been fun.

 

[Smart $]

:lol: Yes, I didn't have your specific edition at hand. But if you have to split hairs by citing which edition to use to achieve your position then your position is weak.

I cited the edition which is to be used for official interpretation. If anything, I see that as making my position stronger... especially because the definition therein not only contains that of yours, it also expands it for what I believe is a better understanding of its usage in context.

We already agreed that present and adjacent are way too ambiguous without further definition. Webster isn't going to improve that. I've contended that 550 establishes what's at hand as 30 ft. If I were to apply your definition of being within the footprint of the structure then there are only rare service drops that meet code. Most of the rods are located inches outside or more. And if we're talking about arms length then how long are your arms? What if you get an inspector without arms? And does Wilt Chamberlain get an easier pass on inspection?

Since your definition for present is so fuzzy then how can you oppose mine, or anyone else's definition for that matter. At least I have a paragraph in the code to stab my finger at.

I said within footprint or arms span, not arms length... and inches outside is well within an arms span. Yes, I understand an arms span is relative to each individual, but it meets the definition - present: at hand... literally :lol:

 

[pfalcon]

I cited the edition which is to be used for official interpretation. If anything, I see that as making my position stronger... especially because the definition therein not only contains that of yours, it also expands it for what I believe is a better understanding of its usage in context.


I said within footprint or arms span, not arms length... and inches outside is well within an arms span. Yes, I understand an arms span is relative to each individual, but it meets the definition - present: at hand... literally :lol:

Well, not for my EL known for saying "M' a'ms a'e too sho't". :rotflmao: They'll never be at hand.

 

[david]

If you are referring to 550.32(D) Additional Outside Electrical Equipment, no, you cannot install a disconnecting means for such right beside the outside mobile home disconnecting means. The requirement says these additional equipment [dis]connecting means must be located in the outside mobile home disconnecting means [enclosure].
QUOTE]

You have an existing mobile home services on a pole installed prior to 550.32(D) being a requirement. The old mobile home is gone. But someone replace the old mobile home with a used one The existing service equipment installed 15 ft from the mobile home can still be used as the service disconnect, as long as you provide an additional local disconnect that does provide for additional outside electrical equipment.

Again there are no mandates in article 550 regarding service equipment. Article 230 provides all the requirements for the service equipment. The only thing article 550 addresses when it comes to mobile home services is the location. Then the article has specific requirements depending on where the service equipment is located to things associated with the mobile home for example 550.32(D)

 

[Smart $]

You have an existing mobile home services on a pole installed prior to 550.32(D) being a requirement. The old mobile home is gone. But someone replace the old mobile home with a used one The existing service equipment installed 15 ft from the mobile home can still be used as the service disconnect, as long as you provide an additional local disconnect that does provide for additional outside electrical equipment.

Again there are no mandates in article 550 regarding service equipment. Article 230 provides all the requirements for the service equipment. The only thing article 550 addresses when it comes to mobile home services is the location. Then the article has specific requirements depending on where the service equipment is located to things associated with the mobile home for example 550.32(D)

As I said before, 550.32 is titled Service Equipment, so everything in 550.32 is regarding service equipment.

Service Equipment. The necessary equipment, usually
consisting of a circuit breaker(s) or switch(es) and fuse(s)
and their accessories, connected to the load end of service
conductors to a building or other structure, or an otherwise
designated area, and intended to constitute the main control
and cutoff of the supply.

(D) Additional Outside Electrical Equipment. Means for
connecting a mobile home accessory building or structure
or additional electrical equipment located outside a mobile
home by a fixed wiring method shall be provided in either
the mobile home service equipment or the local external
disconnecting means permitted in 550.32(A).

Sure an existing disconnecting means can be reused (if compliant for its new use), but you cannot install additional equipment for the disconnecting means of additional outside equipment. If the existing service equipment (or 550.32(A) disconnecting means) does not have provisions for supply and disconnect of additional outside equipment, the old will have to be replaced with one that does.

 

[david]

As I said before, 550.32 is titled Service Equipment, so everything in 550.32 is regarding service equipment.



Sure an existing disconnecting means can be reused (if compliant for its new use), but you cannot install additional equipment for the disconnecting means of additional outside equipment. If the existing service equipment (or 550.32(A) disconnecting means) does not have provisions for supply and disconnect of additional outside equipment, the old will have to be replaced with one that does.

I?m not sure you are following what I am saying.
I am saying the service equipment rule says the service equipment located within 30 ft of the mobile/manufacture home can serve as the local outside disconnect as long as it incorporates provisions for connecting additional equipment.
I am saying if I pull a different used mobile home onto a lot that had a service disconnect 15 ft from the mobile home that does not provide provisions for additional equipment. I do not have to rip out the existing service disconnect. I can if I choose to feed off the existing service disconnect to a disconnect even if on the same pole or pedestal that does provide provisions for additional equipment..
Are ypu saying I must tear out the existing service equipment just because I am with in the 30 ft limit?
If so I cannot figured how you could believe the rule to require that.
That would be like saying you have a general rule and an exception, you must follow the general rule or the exception but you cannot do both.
All I can figure is you do not understand what I am saying

 

[Smart $]

I?m not sure you are following what I am saying.
I am saying the service equipment rule says the service equipment located within 30 ft of the mobile/manufacture home can serve as the local outside disconnect as long as it incorporates provisions for connecting additional equipment.
I am saying if I pull a different used mobile home onto a lot that had a service disconnect 15 ft from the mobile home that does not provide provisions for additional equipment. I do not have to rip out the existing service disconnect. I can if I choose to feed off the existing service disconnect to a disconnect even if on the same pole or pedestal that does provide provisions for additional equipment..
Are ypu saying I must tear out the existing service equipment just because I am with in the 30 ft limit?
If so I cannot figured how you could believe the rule to require that.
That would be like saying you have a general rule and an exception, you must follow the general rule or the exception but you cannot do both.
All I can figure is you do not understand what I am saying

Let me simplify it... each building, structure, or outside electrical equipment must be fed from the equipment containing the main disconnect for the lot.

 

[david]

Let me simplify it... each building, structure, or outside electrical equipment must be fed from the equipment containing the main disconnect for the lot.

I disagree there is no language in this section that says that the well for instance has to be feed from the local disconnect it say additional equipment can be supplied from the service or the local disconnect. You may believe the intent is that the additional equipment must be supplied from the local disconnect but that is not what it says.

In addition from a safty point what difference would it make where the well is feed from, Take a normal single family dwelling what difference would it make if the well was feed from the dwelling or the garage.
Never the less the rule says the equipment must be provide for in the local disconnect or the service. It does not state anywhere that the additional equipment must be supplied from the equipment local to the mobile home.