Mobile Home Grounding

NTesla76

Member
There is a meter pedestal fed from a transformer located about 15' from a mobile home. The meter pedestal has a 100 amp service disconnect in it. A 4-wire feeder runs to the panel in the mobile home. According to 550.32(A), grounding at the disconnecting means shall be in accordance with 250.32. 250.32(A) and (B) talks about buildings or structures supplied by feeders or branch circuits.

Question: Do you have ground rods at the service disconnecting means at the meter pedestal and at the mobile home?
 

augie47

Moderator
Staff member
I find nothing in the NEC that would require the mobile home to have a grounding electrode other than at the service equipment.
 

augie47

Moderator
Staff member
Not the separate structure requirements?
IMO, 550.16 allows the equipment grounding conductor to the service equipment to serve as grounding and since "structure" no longer includes "equipment", I would not consider the mobile home to be a separate structure.
 

NTesla76

Member
IMO, 550.16 allows the equipment grounding conductor to the service equipment to serve as grounding and since "structure" no longer includes "equipment", I would not consider the mobile home to be a separate structure.
Would you not consider the panel inside the mobile home fed with the 4-wire equipment? Maybe I'm not clear on what you're saying.
 

david

Senior Member
I find nothing in the NEC that would require the mobile home to have a grounding electrode other than at the service equipment.
I agree and i do not think it matters if it is a separate structure or not article 550 has always indicated the earthing be at the service location. Article 550 also includes a requirement that a bond be provided from the equipment ground buss of the interior panel to the frame of the mobile home

If someone was to argue the separate structure issue you also have the manufactures instructions that support your position
 

romex jockey

Senior Member
I'm told by past ahj's that anything mobil isn't a structure, and further if the wheels come off, it's no longer mobil.....~RJ~
 

kwired

Electron manager
IMO, 550.16 allows the equipment grounding conductor to the service equipment to serve as grounding and since "structure" no longer includes "equipment", I would not consider the mobile home to be a separate structure.
Would you not consider the panel inside the mobile home fed with the 4-wire equipment? Maybe I'm not clear on what you're saying.
Me neither, I certainly don't feel a mobile home is or should be "equipment".

I do feel that since the disconnecting means must not be on the mobile home yet must be within 30 feet, it sort of is an extension of the building/structure or whatever it may be and is no different than that first disconnecting means for other buildings/structures and that is where grounding electrode system needs to be connected to.
 

kwired

Electron manager
I'm told by past ahj's that anything mobil isn't a structure, and further if the wheels come off, it's no longer mobil.....~RJ~
First Mobil is an oil industry company;)

Second wheels often come off, the axles usually stay on though.

Wheels on or off, not as mobile once tie downs are installed - tornados still move them easily though.

If it is attached to a permanent foundation it isn't a mobile home anymore. Some are designed to used either way, especially multi-section units.
 

david

Senior Member
the fair housing act still classifies them as mobile even if set on a permanent foundation

\The nec rules and manufactures instructions change when placed on a permanent foundation as you know

The rules than allow the service equipment to be attached to the dwelling, or you can install the service within the 30 ft allowance

I see people move there affordable housing from time to time usually not more than 20 miles though
 

NTesla76

Member
Me neither, I certainly don't feel a mobile home is or should be "equipment".

I do feel that since the disconnecting means must not be on the mobile home yet must be within 30 feet, it sort of is an extension of the building/structure or whatever it may be and is no different than that first disconnecting means for other buildings/structures and that is where grounding electrode system needs to be connected to.
I like that reasoning. Makes perfect sense.
 
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