mobile home & ground rods

[kwired]

I personally believe that the rods are needed but you can use the rods that are at the pole. The trailers I see around here, the pole is located within 5 feet of the home. This would make using those rods easier. Anyone see a problem with that.

Most of the time the service or disconnect is 5 feet or so from the home - it does seem pointless to require a separate electrode(s) when it is that close.

Think about two separate buildings that are right next to each other. They each need a separate service or feeder and separate grounding electrode systems. Now take same two buildings and build an enclosed walkway between them or do something that connects them and allows you to call them one building - now they can only have one service, understandable, but a grounding electrode system is no longer required on the second building even though electrically nothing may have changed. The two panels could be hundreds of feet apart if the buildings are large enough, yet the service or feeder disconnect for a mobile home will be a maximum of 30 feet from the mobile home.

Just food for thought.

 

[jwelectric]

What happened to the statement that was used here all the time; :?
?The NEC is a permissive document, if it don?t say you can?t then you can?

Would this not apply here? The fact that the code is silent about the electrode system at the mobile home means one is not required.

 

[kwired]

What happened to the statement that was used here all the time; :?
?The NEC is a permissive document, if it don?t say you can?t then you can?

Would this not apply here? The fact that the code is silent about the electrode system at the mobile home means one is not required.

That is exactly why this discussion is taking place. OP said someone says it is required to have a separate electrode at the mobile home plus one at the disconnect. Most have said it is not required, but does not hurt to install it either.

 

[Dennis Alwon]

What happened to the statement that was used here all the time; :?
?The NEC is a permissive document, if it don?t say you can?t then you can?

Would this not apply here? The fact that the code is silent about the electrode system at the mobile home means one is not required.

I assume you are saying that an electrode is necessary but we could share it with the one at the pole???? That is my take.

 

[david]

1. Service disconnecting means apply article 230
2. Feeder disconnecting means apply 250.32 to the grounding of the feeder disconnecting means
3. Manufactured home distribution panel and main disconnecting means apply article 550.

250.32 should only be applied
A. to how the feeder is configured between the service and the secondary (feeder) disconnecting means
B. to how the feeder is configured between the secondary disconnecting means and the Manufactured home distribution panel
C. to how the feeder is configured between the service disconnecting means and the manufactured home distribution panel when the feeder disconnecting means is not used.
D. 250.32 is only referenced when it comes to grounding of the feeder disconnecting means out side and within 30 feet of the manufactured home.

The only thing article 550 mandates as a grounding means for a manufactured home is the equipment ground that connects to the manufactured homes distribution panel

 

[david]

ok- I'm following a thread on another site. The question is coming down to: Is it required to install a ground rod at a mobile home?
Service will be on a pole within 30 feet of moile home. The 2 parties agree the service is on the pole and rods are required there. The one fellow says a ground rod is required at the mobile home as well. He is saying it is covered by 250.32 Building or Structures Supplied by a Feeder.

What is everyones thoughts, seperate structure ? Ground Rod required ?

After re-reading everything posted here on this subject. I think the confusion is where 250.32 is applied. 550.32 talks about a service disconnect and a secondary disconnect. 250.32 is referenced in 550 as to how the feeders are configured and when it comes to grounding to the secondary disconnect.

Consider the service location as one structure and the secondary disconnect as a second structure. (not the manufactured home) 250.32 is referenced to mandate how this second structures disconnecting means is to be grounded

When it comes to actually grounding the manufactured home when the home is supplied by a feeder 550.16 has special provisions to how this is mandated. A green (identified) insulated equipment ground run with the feeder that supplies the home. 550 goes on to say you cannot identify that equipment ground by stripping away the insulation.

Off subject a little. 550.32 has more stricter requirements to the grounding electrode conductor then any where else in the code when the electrical service is inside or attached to a manufactured home.
It must be routed outside of the structure.

 

[Smart $]

Federal Department of Housing and Urban Development, has jurisdiction over manufactured homes. The manufacture sends instructions on how these are to be supplied.. The only thing electrically that can be inspected is the service equipment and or the feeder to the home. No-one can require anything to be connected to one unless the manufacture has given instructions to do so.

You also have to be certified to install one. You even need additional certification yo inspect anything associated with one.

I never seen anything in any instruction requiring an additional ground rod at one.

HUD requirements: http://ecfr.gpoaccess.gov/cgi/t/tex...v8&view=text&node=24:5.1.4.1.1.9.13.3&idno=24

In particular to this issue, scroll down and read paragraph (k) and subparagraph (k)(3), in which the term grounding electrode appears three times...

 

[iwire]

What happened to the statement that was used here all the time; :?
?The NEC is a permissive document, if it don?t say you can?t then you can?

Would this not apply here? The fact that the code is silent about the electrode system at the mobile home means one is not required.

The code is not silent, there is section 250.32 which no one has been able to show me where it is modified for mobile homes.

 

[david]

I read the section and if the service disconnect is 'elesewhere' you are required to add another disconnecting means near the trailer and that added disconect must be grounded per 250.32.

I still see nothing that says 250.32 does not apply to the trailer / home etc.

it spicificly says 250.32 appies to the secoundary disconnect.
so isn't this talking about the disconnect within 30 ft of the manfactured home
Summary of Changes
550.33 and Exception: Revised for correlation with revisions to 250.32(B) and new exception to 250.32(B).

Exception: For an existing feeder that is installed between the service equipment and a disconnecting means as covered in 550.32(A), it shall be permitted to omit the equipment grounding conductor where the grounded circuit conductor is grounded at the disconnecting means in accordance with 250.32(B) Exception.

 

[iwire]

it spicificly says 250.32 appies to the secoundary disconnect.so isn't this talking about the disconnect within 30 ft of the manfactured home

Yes, it says the grounding at that disconcect will comply with 250.32, it does not say in anyway that it is in lue of of an electrode at the mobile home.

Summary of Changes
550.33 and Exception: Revised for correlation with revisions to 250.32(B) and new exception to 250.32(B).

Exception: For an existing feeder that is installed between the service equipment and a disconnecting means as covered in 550.32(A), it shall be permitted to omit the equipment grounding conductor where the grounded circuit conductor is grounded at the disconnecting means in accordance with 250.32(B) Exception.

Again, that is about the disconnect, not the mobile home.

A disconnect mounted on a pole is a structure per definition and would require an electrode anyway.

 

[david]

Yes, it says the grounding at that disconcect will comply with 250.32, it does not say in anyway that it is in lue of of an electrode at the mobile home.




Again, that is about the disconnect, not the mobile home.

A disconnect mounted on a pole is a structure per definition and would require an electrode anyway.

Do you agree the feeder from a disconnect is the only thing being installed at the mobile home.
are you saying that 250.32 reguires a grounding electrode conductor to be connected to a mobile home

I should have said when being supplied by a feeder

 

[david]

Do you agree the feeder from a disconnect is the only thing being installed at the mobile home.
are you saying that 250.32 reguires a grounding electrode conductor to be connected to a mobile home

I should have said when being supplied by a feeder

When I got my certification to inspect the installation of service equipment for manufactured homes I was told I could not require anything but the correct connection and size of a feeder. When the manufactured home was supplied by a feeder.

In this state in addition to being certified as an electrical inspector. I also had to go to classes a receive certification to inspect on site equipment for manufactured homes. I am not sure if I remember right but I thought that stemmed from a federal req. I’ll have to go back and check

 

[david]

The code is not silent, there is section 250.32 which no one has been able to show me where it is modified for mobile homes.

You may be right but the affordable housing act would have left that in the hands of the manufacture and the written instruction with a particular mobile home. I believe it is the intent of 550.16 not to require that. That may be an oversight on 250.32 not to include an exception for manufacture housing

Never the less at the point of resale when a manufactured home is moved it loses its HUD certification and 250.32 may come back into play at that point.

 

[kwired]

Never the less at the point of resale when a manufactured home is moved it loses its HUD certification ..

A point I was attempting some clarification on earlier in this thread.

Kind of like buying a car, it will meet emissions, safety and other standards when it is first purchased. There are no guarantees it will after that point in time, especially if any modifications are made to it. And there is no one out there re-evaluating it to make sure it still meets the original standards.

 

[hurk27]

You may be right but the affordable housing act would have left that in the hands of the manufacture and the written instruction with a particular mobile home. I believe it is the intent of 550.16 not to require that. That may be an oversight on 250.32 not to include an exception for manufacture housing

Never the less at the point of resale when a manufactured home is moved it loses its HUD certification and 250.32 may come back into play at that point.

I was told by HUD that the only time CFR 24 3280.800 does not apply to a once HUD certified trailer is it has been modified beyond meeting the original requirements of manufacture, and or has been permanently mounted to a permant foundation that makes it no longer mobile.

CFR 24 3280.800 supersedes the NEC and does not require a grounding electrode at the trailer.

We have trailers move from park to park here and they are still hands off according FHA/HUD

 

[kwired]

I was told by HUD that the only time CFR 24 3280.800 does not apply to a once HUD certified trailer is it has been modified beyond meeting the original requirements of manufacture, and or has been permanently mounted to a permant foundation that makes it no longer mobile.

CFR 24 3280.800 supersedes the NEC and does not require a grounding electrode at the trailer.

We have trailers move from park to park here and they are still hands off according FHA/HUD

Who makes sure the HUD certification is maintained? Maybe where you are there is somebody, around here closest thing I am aware of is our state electrical inspectors, AFAIK they are only concerned about NEC as it is the only standard that is used as a law in the State Electrical Act.

They wouldn't inspect a mobile home anyway except for when one is connected to a new service, but even then unless it was obvious that additional wiring was done in the home would only look at the service and feeder to the home.

 

[pfalcon]

You may be right but the affordable housing act would have left that in the hands of the manufacture and the written instruction with a particular mobile home. I believe it is the intent of 550.16 not to require that. That may be an oversight on 250.32 not to include an exception for manufacture housing

Never the less at the point of resale when a manufactured home is moved it loses its HUD certification and 250.32 may come back into play at that point.

The clarification should be in 550 not 250. IMO.

 

[Smart $]

...

CFR 24 3280.800 supersedes the NEC and does not require a grounding electrode at the trailer.

...

That's an interpretation. Read the following portion...

Subpart I—Electrical Systems
? 3280.801 Scope.
(a) Subpart I of this part and Part II of Article 550 of the National Electrical Code (NFPA No. 70–2005) cover the electrical conductors and equipment installed within or on manufactured homes and the conductors that connect manufactured homes to a supply of electricity.
(b) In addition to the requirements of this part and Part II of Article 550 of the National Electrical Code (NFPA No. 70–2005), the applicable portions of other Articles of the National Electrical Code must be followed for electrical installations in manufactured homes. The use of arc-fault breakers under Articles 210.12(A) and (B), 440.65, and 550.25(A) and (B) of the National Electrical Code, NFPA No. 70–2005 is not required. However, if arc-fault breakers are provided, such use must be in accordance with the National Electrical Code, NFPA No. 70–2005. Wherever the requirements of this standard differ from the National Electrical Code, these standards apply.

...and here's the part I referred to in my earlier post...

(k) Where the calculated load exceeds 50 amperes or where a permanent feeder is used, the supply shall be by means of:
(1) One mast weatherhead installation installed in accordance with Article 230 of the National Electrical Code, NFPA No. 70–2005, containing four continuous insulated, color-coded, feeder conductors, one of which shall be an equipment grounding conductor; or
(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
(3) Service equipment installed on the manufactured home in accordance with Article 230 of the National Electrical Code, NFPA No. 70–2005, and the following requirements:
(i) The installation shall be completed by the manufacturer except for the service connections, the meter and the grounding electrode conductor;
(ii) Exterior equipment, or the enclosure in which it is installed must be weatherproof and installed in accordance with Article 312.2(A) of the National Electrical Code, NFPA No. 70–2005, and conductors must be suitable for use in wet locations;
(iii) Each neutral conductor must be connected to the system grounding conductor on the supply side of the main disconnect in accordance with Articles 250.24, 250.26, and 250.28 of the National Electrical Code, NFPA No. 70–2005.
(iv) The manufacturer shall include in its written installation instructions one method of grounding the service equipment at the installation site;
(v) The minimum size grounding electrode conductor shall be specified in the instructions; and
(vi) A red “Warning” label shall be mounted on or adjacent to the service equipment. The label shall state:

“Warning—do not provide electrical power until the grounding electrode is installed and connected (see installation instructions).”

 

[david]

I was told by HUD that the only time CFR 24 3280.800 does not apply to a once HUD certified trailer is it has been modified beyond meeting the original requirements of manufacture, and or has been permanently mounted to a permant foundation that makes it no longer mobile.

CFR 24 3280.800 supersedes the NEC and does not require a grounding electrode at the trailer.

We have trailers move from park to park here and they are still hands off according FHA/HUD

ECD economic development corporation which is basically HUD at the PA state level and I carry Residential Inspection for Manufactured and Modular Homes certification under Pa Act 158

Was clear to us the HUD certification was only good from the manufacture to the first site if a manufactured home was moved from the site of first sale all the state adopted building codes become applicable to that structure.
For example manufacture homes truss systems are not designed to PA Live and dead loads (snow loads)
If you move a manufacture home the building official can require that the roof system conform to the International residential building code here in PA.

 

[david]

That's an interpretation. Read the following portion...




...and here's the part I referred to in my earlier post...

3) Service equipment installed on the manufacturedhome in accordance with Article 230 of the National Electrical Code, NFPA No. 70?2005, and the following requirements: