Mobile Home Service and Grounding Electrode Conductor To Rod

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transman2

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Brooklet,Ga.
We had a Contractor move on site and installed a Temporary Mobile Home to work out of. The EC ran a conduit to an electrical panel about 50' away. The breaker is a 2 pole that matches the MH panel main. My question is should the EC install a service disconnect within 30' and drive a ground rod or since he's within line of sight of the MH just install a ground rod adjacent the MH and run a GEC from the MH main panel inside. After reading definition "structure" and 250.32, 250.50, and 550.32 I am confused. Need insight! Thanks!!
 
550.4 would seem to me to indicate that 550.32 would be applicable, however, in my experience enforcement has been lax when it comes to contractor job trailers.
The same hold true for 250.32 and 250.50 due to the "temporary" nature of most of these installations.
 
transman2 said:
We had a Contractor move on site and installed a Temporary Mobile Home to work out of. The EC ran a conduit to an electrical panel about 50' away. The breaker is a 2 pole that matches the MH panel main. My question is should the EC install a service disconnect within 30' and drive a ground rod or since he's within line of sight of the MH just install a ground rod adjacent the MH and run a GEC from the MH main panel inside. After reading definition "structure" and 250.32, 250.50, and 550.32 I am confused. Need insight! Thanks!!
Click to expand...

I am assuming temporary.

Read these two and see if this helps.

590.2 All Wiring Installations.
(A) Other Articles. Except as specifically modified in this
article, all other requirements of this Code for permanent
wiring shall apply to temporary wiring installations.

550.4 General Requirements.
(A) Mobile Home Not Intended as a Dwelling Unit. A
mobile home not intended as a dwelling unit ? for example,
those equipped for sleeping purposes only, contractor?s
on-site offices, construction job dormitories, mobile
studio dressing rooms, banks, clinics, mobile stores, or intended
for the display or demonstration of merchandise or
machinery ? shall not be required to meet the provisions
of this article pertaining to the number or capacity of circuits
required. It shall, however, meet all other applicable
requirements of this article if provided with an electrical
installation intended to be energized from a 120-volt or
120/240-volt ac power supply system. Where different voltage
is required by either design or available power supply
system, adjustment shall be made in accordance with other
articles and sections for the voltage used.

Now is it a mobile home or a manufactured home?
 
augie47 said:
550.4 would seem to me to indicate that 550.32 would be applicable, however, in my experience enforcement has been lax when it comes to contractor job trailers.
The same hold true for 250.32 and 250.50 due to the "temporary" nature of most of these installations.
Click to expand...

Agreed.

Now for the debate.

That disconnect can be located inside the structure.

Example:

I am standing at the back door, exterior wall, and can see the panel usually located just inside of the door.
 
jxofaltrds said:
Agreed.

Now for the debate.

That disconnect can be located inside the structure.

Example:

I am standing at the back door, exterior wall, and can see the panel usually located just inside of the door.
Click to expand...

Wow! Did not see this one coming. Where is the backup for disconnect being located inside. Can't one section of the code supersede another. Please explain this statement.
 
transman2 said:
I believe a mobile home is considered a building/structure and it has more than one circuit so shouldn't it have a grounding electrode installed.
Click to expand...
If one considers the remote service disconnect as a "structure", IMO, you are correct. I see nothing in the Code directing me otherwise (perhaps someone will enlighten us). That said, for unknown reasons, it has never been required in any jurisdiction with which I am aware,.
 
transman2 said:
Wow! Did not see this one coming. Where is the backup for disconnect being located inside. Can't one section of the code supersede another. Please explain this statement.
Click to expand...

From 550.32

550.32 Service Equipment.
(A) Mobile Home Service Equipment.

......The service equipment shall be permitted to
be located elsewhere on the premises, provided that a disconnecting
means suitable for use as service equipment is located within sight from and not more than 9.0 m (30 ft)
from the exterior wall of the mobile home it serves and is
rated not less than that required for service equipment in
accordance with 550.32(C). Grounding at the disconnecting
means shall be in accordance with 250.32. .....

Doesn't say it can't be inside just that the:
(A) Mobile Home Service Equipment. The mobile home
service equipment shall be located adjacent to the mobile
home and not mounted in or on the mobile home.

Never had anyone install it that way but if they did should/could I approve it?
 
jxofaltrds said:
From 550.32

550.32 Service Equipment.
(A) Mobile Home Service Equipment.

......The service equipment shall be permitted to
be located elsewhere on the premises, provided that a disconnecting
means suitable for use as service equipment is located within sight from and not more than 9.0 m (30 ft)
from the exterior wall of the mobile home it serves and is
rated not less than that required for service equipment in
accordance with 550.32(C). Grounding at the disconnecting
means shall be in accordance with 250.32. .....

Doesn't say it can't be inside just that the:
(A) Mobile Home Service Equipment. The mobile home
service equipment shall be located adjacent to the mobile
home and not mounted in or on the mobile home.

Never had anyone install it that way but if they did should/could I approve it?
Click to expand...
I understand, now tell us just how practical it is to install it in the mobile home and at same time not mount it in or on the home? If someone does meet those requirements then fine let it pass, and probably need to give them a hand for their creativity as well.
 
kwired said:
I understand, now tell us just how practical it is to install it in the mobile home and at same time not mount it in or on the home? If someone does meet those requirements then fine let it pass, and probably need to give them a hand for their creativity as well.
Click to expand...

These are two "different' disconnects.

One is the mobile home service equipment disconnect.

The other is mobile home disconnecting means. I believe that this one is allowed to be "on" the home or any part of the structure if it is more than 2' off the ground.
 
jxofaltrds said:
These are two "different' disconnects.

One is the mobile home service equipment disconnect.

The other is mobile home disconnecting means. I believe that this one is allowed to be "on" the home or any part of the structure if it is more than 2' off the ground.
Click to expand...

Thanks! I think this one needs to be sent in for review to change code.
 
jxofaltrds said:
Agreed.

Now for the debate.

That disconnect can be located inside the structure.

Example:

I am standing at the back door, exterior wall, and can see the panel usually located just inside of the door.
Click to expand...

550.10 Power Supply.
(A) Feeder. The power supply to the mobile home shall be a feeder assembly consisting of not more than one listed 50-ampere mobile home power-supply cord with an integrally molded or securely attached plug cap or a permanently installed feeder.

F) Point of Entrance. The point of entrance of the feeder assembly to the mobile home shall be in the exterior wall, floor, or roof.
 
david said:
550.10 Power Supply.
(A) Feeder. The power supply to the mobile home shall be a feeder assembly consisting of not more than one listed 50-ampere mobile home power-supply cord with an integrally molded or securely attached plug cap or a permanently installed feeder.

F) Point of Entrance. The point of entrance of the feeder assembly to the mobile home shall be in the exterior wall, floor, or roof.
Click to expand...

550.4 General Requirements.
(A) Mobile Home Not Intended as a Dwelling Unit.
 
jxofaltrds said:
550.4 General Requirements.
(A) Mobile Home Not Intended as a Dwelling Unit.
Click to expand...

The mobile home construction trailer is required to be supplied by a feeder that originates outside of the mobile job trailer. How can the disconnect suitable for service equipment supply a feed that originates outside of the trailer be mounted inside the trailer?

Never mind I may not even be understanding what you are saying, I would need clarification as to which of the three disconnects commonly associated with a mobile home you are referring to
 
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david said:
Never mind I may not even be understanding what you are saying, I would need clarification as to which of the three disconnects commonly associated with a mobile home you are referring to
Click to expand...
Same here. I also am not all that familiar with all requirements when it is not intended as a dwelling - but have always understood the supply requirements to be nearly the same for either, especially for grounding and bonding.
 
david said:
The mobile home construction trailer is required to be supplied by a feeder that originates outside of the mobile job trailer. How can the disconnect suitable for service equipment supply a feed that originates outside of the trailer be mounted inside the trailer?

Never mind I may not even be understanding what you are saying, I would need clarification as to which of the three disconnects commonly associated with a mobile home you are referring to
Click to expand...

Suitable and 'serving as' are two different animal.

The one in red is the one that I am referring to.

550.32(A)
.....The service equipment shall be permitted to be located elsewhere on the premises, provided that a disconnecting
means suitable for use as service equipment is located within sight from and not more than 9.0 m (30 ft)
from the exterior wall of the mobile home it serves and is rated not less than that required for service equipment in
accordance with 550.32(C). Grounding at the disconnecting means shall be in accordance with 250.32.

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.

Now does 550.4(A) negate 550.32(C)?

"....shall not be required to meet the provisions
of this article pertaining to the number or capacity of circuits
required."
 
Mike there are three disconnects commonly associated mobile homes in the section you are discussing
The service disconnect (suitable for use as service equipment) more than 30 ft from the job trailer, supplying a feeder and a disconnect (suitable for use as service equipment) located no further than 30 ft from the job trailer supplying a feeder that enters the trailer and a required disconnect. These are usually suitable for use as service disconnects but there is no requirement that this third distribution panel be suitable for use as service equipment.

The job trailer is required to be supplied a feeder from a disconnect that is suitable for use as service equipment located not further than 30 feet from the trailer

(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).

If you notice the local disconnecting means permitted in 550.32 (A) is required to be external
 
jxofaltrds said:
Agreed.

Now for the debate.

That disconnect can be located inside the structure.

Example:

I am standing at the back door, exterior wall, and can see the panel usually located just inside of the door.
Click to expand...

david said:
Mike there are three disconnects commonly associated mobile homes in the section you are discussing
The service disconnect (suitable for use as service equipment) more than 30 ft from the job trailer, supplying a feeder and a disconnect (suitable for use as service equipment) located no further than 30 ft from the job trailer supplying a feeder that enters the trailer and a required disconnect. These are usually suitable for use as service disconnects but there is no requirement that this third distribution panel be suitable for use as service equipment. The service equipment shall be permitted to
be located elsewhere on the premises,

The job trailer is required to be supplied a feeder from a disconnect that is suitable for use as service equipment located not further than 30 feet from the trailer Disagree

(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).

If you notice the local disconnecting means permitted in 550.32 (A) is required to be external Local? False
Click to expand...

So are you saying that I am right or wrong in my comments that got this started?
 
jxofaltrds said:
So are you saying that I am right or wrong in my comments that got this started?
Click to expand...

I am saying that you are wrong that the local (external within 30 feet) disconnect permitted in 550.32(A) is required to be external

550.32 Service Equipment. (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).
 
I believe your comments to indicate that a service disconnect can be more than thirty feet from the trailer and a feed can go from the service disconnect directly into the mobile home to a disconnect that qualifies as the disconnect in 550 32 (A) there by having no external disconnect with in 30 ft. of the trailer

If I understand your comments than I say you are wrong.
 
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