So what is the conflict? If the main requirement is the service equipment must be located not more than 30' and within sight of the mobile home's exterior, how does it conflict if the service equipment is at a greater distance but an additional service-rated disconnect is within the specified distance. It is saying there must be a power supply disconnect within 30' exterior to and sight of a mobile home under any and all circumstances.
mobile home & ground rods
- Thread starter luckyshadow
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You're missing the whole 550 says its adjacent and 250 applies to remote conflict. Adjacent and remote are contrary terms.
As your definitions refer to the line side of the equipment under discussion, and the conflict is on the load side, I don't see the relevance of those definitions. :dunce: maybe it's just me.
Adjacent and remote are relative terms and completely ambiguous without perspective , context, reference, or such.
For example, from your location you could say a resident on the other side of my small hometown is adjacent to me, but from my location, he resides in a rather remote location. Both terms can be used to describe the separation just by putting a different perspective on the matter.
So perhaps you can offer some context, so that I may understand better...
Maybe...
david
Senior Member
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- Pennsylvania
550.13 Receptacle Outlets.
B) GFCI protection. GFCI protection shall be provided for receptacle outlets serving countertops in kitchens,
and receptacle outlets located within 1.8 m (6 ft) of a wet bar sink.
Exception: Receptacles installed for appliances in dedicated spaces, such as for dishwashers, disposals, refrigerators, freezers, and laundry equipment
.
Feeders supplying branch circuits shall be permitted to be protected by a ground-fault circuit-interrupter in lieu of the provision for such interrupters specified herein.
(G) Receptacle Outlets Not Required. Receptacle outlets shall not be required in the following locations:
(2) In the wall space behind doors that can be opened fully against a wall surface
How many times did we here guys ask about how about dedicated rec. to the washer with in six ft of the laundry sink?
What about the space be hind a door on a wall does that need a rec?.
The more I look at it the evidence it seems to indicate that the scoping statement in 550.1 says what it says and that does seem to modify the general requirements of the code. This opinion is not popular here but it is mine
It may not technically match the style Manuel but HUD could have assemble there own panel of experts and written there own electrical standards for manufactured homes. HUD had no interest in the NEC as a Whole they where only interested in the electrical provisions that effect Mobile homes. The scoping provisions in 550.1 seem to wrap this article up in a nice package for HUD to incorporate this article into there standers
david
Senior Member
- Location
- Pennsylvania
As far as if a ground rod is mandate to be connected to a mobile home as other separate structures are in the general provisions of the NEC I vote No
it is not required (unless The service equipment is installed on or in a manufactured home)
I also Believe it wont hurt anything either.
So if we install one just because we want to or we install one because we feel it is or an inspector interrupts the NEC to require one we must beware of this statement
(3) Means shall be provided for the connection of a grounding electrode conductor to the service equipment and routing it outside the structure.
I’m not sure what the hazard is in routing one inside a manufactured home never the less the provision is their.
it is not required (unless The service equipment is installed on or in a manufactured home)
I also Believe it wont hurt anything either.
So if we install one just because we want to or we install one because we feel it is or an inspector interrupts the NEC to require one we must beware of this statement
(3) Means shall be provided for the connection of a grounding electrode conductor to the service equipment and routing it outside the structure.
I’m not sure what the hazard is in routing one inside a manufactured home never the less the provision is their.
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jwelectric
Senior Member
- Location
- North Carolina
I agree there is no requirement to install a grounding electrode system for a mobile home distribution panel.
In the scope of 550 it clearly states; The provisions of this article cover the conductors that connect mobile and manufactured homes to a supply of electricity,
Again in 550.4(C); The provisions of this article shall apply to mobile homes intended for connection to a wiring system rated 120/240 volts, nominal, 3-wire ac, with a grounded neutral conductor.
The grounding is covered in 550.16; Grounding of both electrical and nonelectrical metal parts in a mobile home shall be through connection to a grounding bus in the mobile home distribution panelboard and shall be connected through the green-colored insulated conductor in the supply cord or the feeder wiring to the grounding bus in the service-entrance equipment located adjacent to the mobile home location. (Up to 30 feet away 550.32)
And then again in 550.33(A)(2); Feeder conductors shall be installed in compliance with 250.32(B).
This section bypasses the requirement found in 250.32(A) and goes straight to (B) relieving the requirement of installing the electrode system.
On a manufactured home there will be some sort of raceway or chase to installing the GEC and this prevision is not supplied for a trailer. Excuse me I meant a mobile home.
In the scope of 550 it clearly states; The provisions of this article cover the conductors that connect mobile and manufactured homes to a supply of electricity,
Again in 550.4(C); The provisions of this article shall apply to mobile homes intended for connection to a wiring system rated 120/240 volts, nominal, 3-wire ac, with a grounded neutral conductor.
The grounding is covered in 550.16; Grounding of both electrical and nonelectrical metal parts in a mobile home shall be through connection to a grounding bus in the mobile home distribution panelboard and shall be connected through the green-colored insulated conductor in the supply cord or the feeder wiring to the grounding bus in the service-entrance equipment located adjacent to the mobile home location. (Up to 30 feet away 550.32)
And then again in 550.33(A)(2); Feeder conductors shall be installed in compliance with 250.32(B).
This section bypasses the requirement found in 250.32(A) and goes straight to (B) relieving the requirement of installing the electrode system.
On a manufactured home there will be some sort of raceway or chase to installing the GEC and this prevision is not supplied for a trailer. Excuse me I meant a mobile home.
david
Senior Member
- Location
- Pennsylvania
My one last thought on this Note (3) is only found in relation ship to when a service is in ( in or on) a manufacture home. If it is a hazard ina manufacture home it would be a hazard in a mobile home. i beleave this is also anindication that a grounding electrode conductor was never intended to be connected to a mobile home distrubution panel
david
Senior Member
- Location
- Pennsylvania
I don?t think we differ on this but, do you believe it is required for a manufacture home if the supply system is set up identical to a mobile home (trailer)
That just didn?t seem clear to me in this post
Good, we agree.
NFPA70:2011:550.32(A) Service Equipment said:
I believe the above defines adjacency for this context. And remote is by normal definitions something that is not adjacent.
NFPA70:2011:250.32(D) said:
So, since 550.32(A) defines the service as adjacent and 250.32(D) only applies to remote service, I don't see where 250.32(D) applies to the mobile home.
jwelectric
Senior Member
- Location
- North Carolina
Yes because a manufactured home is the same as a moblle home unless the service is mounted on the home.
See 550.32 (B) shall be premitted.........
- Location
- Massachusetts
I think you are the only one that does not see these as separate structures.
Sort of, I don't agree the service post is a structure but I'll live with it. I'm off on a different phrasing. I mean - the code says what it says - not what we want it to say. Right? So whether I think the structure definition is absurd or not - blarrgh! It goes to the change committee ... or not if I lack the ambition to submit a change.
So I guess where I'm at is this:
The service structure is part of the installation at the mobile home, therefore the mobile home is supplied by a service not a feeder; even though a feeder is part of the primary wiring to the distribution panel. Therefore 250.32(A) does not apply.
The service structure is defined by 550.32 as adjacent (within 30') which means it's not remote; therefore 250.32(D) does not apply.
jwelectric
Senior Member
- Location
- North Carolina
I think too much emphasis is being placed on whether or not the mobile home is a separate structure or building. As defined in Article 100 it is obvious that it is but does this matter to the question at hand?
What needs addressing is whether or not a grounding electrode needs to be established at the mobile home. As outlined in 550 one is not required to be established. The methods for connecting the distribution panel to the electrode system are outlined in 550 and the only reference to 250.32 is to 250.32(B) thereby skipping 250.32(A).
renosteinke
Senior Member
- Location
- NE Arkansas
I believe I have posted twice in this thread the position of the State of Nevada that mobile homes are appliances, not structures. The language of the NEC, and the UL listing of mobile homes, tends to support that position.
I'm with you right up to where you say 250.32(D). This subsection applies to disconnecting means not located at the building or structure they disconnect... "in accordance with the provisions of 225.32, Exception No. 1 and No. 2, 700.12(B)(6), 701.11(B)(5), or 702.11..." I would consider it an extremely rare case where a mobile or manufactured home were subjected to this requirement... especially because most such homes have a disconnecting means located in or on the "structure".
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I can see you are not going to change your position based solely on textual content. So let's consider concepts. Yet to be discussed to any great depth is the size of the EGC. Under 2008/2011 the feeder EGC connects GES's at separate structures. However, no GES at mobile and manufactured homes supplied by feeder is essentially saying the feeder EGC serves the purpose of a GEC. With EGC sizing requirements as they are, there isn't a problem for 100A services and feeders. However, when we get to higher-rated services and feeders, I see the EGC as being inadequately sized to serve a dual role as GEC. Consider EGC and GEC sizing for a 200A service and feeder connection for both separate structures and m&m homes...
Well, some were saying 250.32 applies and 550 only adds to it. So I was looking at 250 from that perspective. (D) says it applies to remote where 550 defines the MH service to be adjacent; I take that to mean not remote. So I feel (D) cannot apply.
I agree. 100 defines the service and MH as separate structures. And I think all the questions for which that was important are closed.
iwire was stressing that all of 250.32 applies unless excluded ($10) by conditions ($10) or by explicit ($10) exception ($10). (I get paid for obfuscation $10).
Specifically the lack of mention of 250.32(A) in 550 does not remove enforcement of 250.32(A). per iwire. Presuming I'm not presuming overmuch.
NFPA70:2011:250.32(A) said:
The grounding electrode is present at the service structure; and per either (B) or (C) a grounding conductor is run with the supply conductors. Where does an additional ground rod become required?
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Okay, I'm putting on my hat :dunce: again. And hoping I don't beggar up the acronyms.
The GES is installed at the service structure.
The EGC as given in 550.16(B)(1) is run through the feeder.
So the question is: Where is the GEC connected? Which I thought was being addressed by 550.16(A)?
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