service to a trailer

[mh183]

i would like to wire this as structure if it is a gray area, and may be it should not mater if the first disconnect is fused or not but one big question does it make any difference if the purpose of this disconnect before the meeter is power co requested for service service is only 120-240v

 

[Smart $]

...one big question does it make any difference if the purpose of this disconnect before the meeter is power co requested
...

Makes no difference other than to confuse the issue :grin:

My take on the matter is first it has to be established whether this is an Article 545 or an Article 550 application.

If the former, grounding to grounded bonding occurs at the disconnect by the meter and is kept separate thereafter on the load side.

If the latter, 550.32 states the service disconnect is to be located within 30' of and visible from the exterior wall of the trailer. This makes the entire run to the trailers service conductors. Each trailer is required to have its own service. While the disconnect by the meter is service equipment, so is the disconnects by the trailers... but the ones close to the trailers are technically the service disconnect for individual trailers, as required, making 250.32 applicable only at these disconnects and to the load side of them.

...but that's JMSO (just my stupid opinion)

 

[RUWired]

If the latter, 550.32 states the service disconnect is to be located within 30' of and visible from the exterior wall of the trailer. This makes the entire run to the trailers service conductors. Each trailer is required to have its own service. While the disconnect by the meter is service equipment, so is the disconnects by the trailers... but the ones close to the trailers are technically the service disconnect for individual trailers, as required, making 250.32 applicable only at these disconnects and to the load side of them.

Smart $, 550.32 goes on to say, the service disconnect can be located else where but, a service rated disconnect is required within 30'. IMO after the service disconnect 200' away, the cables afterward are feeder conductors.
Rick

 

[benaround]

Smart $, 550.32 goes on to say, the service disconnect can be located else where but, a service rated disconnect is required within 30'. IMO after the service disconnect 200' away, the cables afterward are feeder conductors.
Rick

Rick, 550.33(A)excp. addresses this issue. NEC2005

 

[Smart $]

Smart $, 550.32 goes on to say, the service disconnect can be located else where but, a service rated disconnect is required within 30'. IMO after the service disconnect 200' away, the cables afterward are feeder conductors.
Rick

Actually, 550.32 goes on to say,

"service equipment shall be permitted to be located elsewhere on the premises,..."​

It does not specifically state the service equipment located elsewhere is the service disconnecting means, so it goes on to say

"...provided that a disconnecting means suitable for use as service equipment..."​

be located near the unit and goes on to say,

"Grounding at the disconnecting means shall be according to 250.32."​

Additionally, this is all under a section header reading

"Service Equipment"​

 

[Smart $]

Rick, 550.33(A)excp. addresses this issue. NEC2005

...which changes to only existing installations where NEC 2008 has been adopted.

Being that 550.32(A) did not change, the change in the 550.33(A) Exception seems to be a contradiction.

 

[RUWired]

... .

Being that 550.32(A) did not change, the change in the 550.33(A) Exception seems to be a contradiction.

550.32(A) refers you to 250.32 which has changed to agree with 550.33(A) exception. Only through existing feeders.
Rick

 

[RUWired]

Actually, 550.32 goes on to say,

"service equipment shall be permitted to be located elsewhere on the premises,..."​

It does not specifically state the service equipment located elsewhere is the service disconnecting means, so it goes on to say

Did i hit a nerve? If it says the service disconnect may be located else where, what else would they be talking about.

"...provided that a disconnecting means suitable for use as service equipment..."​

be located near the unit and goes on to say,

Thats what i said

"Grounding at the disconnecting means shall be according to 250.32."​

which would require 4 conductors unless existing.


​

Additionally, this is all under a section header reading
"Service Equipment"

And that is why i said the service equipment can be remote.

 

[Smart $]

Did i hit a nerve?

Just trying to "get on the same page", so to speak... :wink:

The problem with Article 550 is that it refers to two distinctly different disconnecting means, one located outside and one located inside the unit while not referring directly to either as the service disconnect. Additionally,it mentions two different locations for service equipment, one within 30' of each unit and the possibility of other [additional?] service equipment located elsewhere on the premises, again while not referring directly to either location as that of the service disconnect. So we have two to three possible locations to disconnect service and none have been clearly defined as the service disconnecting means.

However, 550.32(A) specifically states, in the last sentence, the outside disconnecting means required to be within 30' shall be grounded according to 250.32. The Exception to 550.33(A) of NEC 2005 edition seems to clarify that. Yet the same Exception in the NEC 2008 edition muddies the interpretation.


Amid all the apparent supposition, you must remember that Article 550 is one that can modify any Chapter 1-4 requirement.