# Temp Service/Trailer



## MDShunk (Jan 7, 2007)

You always need to drive a ground rod at a job trailer. Need to catch the frame too if the panel isn't already connected to it.


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## Dennis Alwon (May 9, 2009)

You can use the same rod at the pole. Just run a grounding electrode conductor from the the trailer equipment ground bar to the rod.


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## manchestersparky (Mar 25, 2007)

If that SER is 2 hot conductors, 1 insulated grounded conductor and a bare grounding conductor , then you have an illegal installation.

The grounding conductor in the feed to the trailer must be insulated and identified by being green in color.


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## HARRY304E (Sep 15, 2010)

manchestersparky said:


> If that SER is 2 hot conductors, 1 insulated grounded conductor and a bare grounding conductor , then you have an illegal installation.
> 
> The grounding conductor in the feed to the trailer must be insulated and identified by being green in color.


Code reference??:blink:


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## manchestersparky (Mar 25, 2007)

Article 550.4 (A) Mobile Home Not Intended as a Dwelling Unit.
This article tells us that Contractors on site offices shall not be required to meet the provisions of article 550 as far as the number of or capacity of circuits required by the article. IT does state that the contractors office shall meet all other requirements of the article if the trailer is to be energized from a 120 volt or 120/240 volt AC power supply.

Article 550.16 (B) (1) Supply Cord or Permanent Feeder-
States that the green colored insulated grounding wire in the supply cord or permanent feeder........

Article 550.33 (A) (1) Feeder conductors shall consist of either a listed cord, factory installed in accordance with 550.10(B), or a permanently installed feeder consisting of 4 insulated, color coded conductors.


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## HARRY304E (Sep 15, 2010)

manchestersparky said:


> Article 550.4 (A) Mobile Home Not Intended as a Dwelling Unit.
> This article tells us that Contractors on site offices shall not be required to meet the provisions of article 550 as far as the number of or capacity of circuits required by the article. IT does state that the contractors office shall meet all other requirements of the article if the trailer is to be energized from a 120 volt or 120/240 volt AC power supply.
> 
> Article 550.16 (B) (1) Supply Cord or Permanent Feeder-
> ...


Trailers are in article 552

Article 552.37 (C)


*(C) Bonding Conductor Requirements. *
​​Grounding terminals​
shall be of the solderless type and listed as pressure
terminal connectors recognized for the wire size used. The
bonding conductor shall be solid or stranded, insulated or​​​
bare, and shall be 8 AWG copper minimum or equivalent​

Also temporary wiring is coverd in Article 590​ 

You are correct about mobile homes in article 550.:thumbsup:​


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## manchestersparky (Mar 25, 2007)

Yes Park Trailers are covered in article 552.
There article you quoted is article 552.57 (C)
Article 552.57 = BONDING of Non-Current-Carrying Metal Parts.
552.57(C) - Covers the conductor Requirements of the BONDING conductor.

Your article is referring to bonding and I am talking about the GROUNDING conductor in the feeder to the mobile home.

Park Trailers are similar to mobile homes / manufactured homes covered in 550.
552.2 Park Trailer is a unit built on a single chasis mounted on wheels and has a gross trailer area not exceeding 400 Sq. Ft. in the set up mode.

552.4 General requirements.
A park trailer as specified in 552.2 is intended for Seasonal use. It is not intended as a permanent dwelling unit or for commercial uses such as banks, clinics, offices, or similar.

So according to 552.2& 552.4 those office trailers used on job sites are not park Trailers. Take for example the general contractors double wide contractors office / project meeting trailers. They are more than 400 Sq. Ft. and they are not on a single chasis. They come apart as 2 units therefor 2 chasis.

So Park Trailers are not what we are discussing, but rather Mobile home not intended as a dwelling unit.

(Park Trailer --- Think "camper")


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## zss42002 (Feb 17, 2008)

since the neutral and the ground of the trailer have to be isolated. the grounding electrode conductor will connect to the grounding conductor of the ser at the first disconnecting means? am i interpreting this correctly? 

i ran into a situation today i have never wired a temp service to a site trailer. what i have is off transformer inside building 120/240v going to a gfci breaker disconnect. from disconnect 3#1's and a ground going to ser, outside building to a disconnect at trailer. i have to drive a ground rod at trailer and connect to disconnect and bond to the grounding conductor of the ser and connect trailer to ground rod also and keep neutral isolated at all points. am i following this right?


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