elec. in const. trlr.

menu item · 09-25-2009, 12:36 PM

Hi folks
I have an 8'by 24' constr./office trlr. that has a 125/250x 50' cord that plugs in on job sites.
The only power near the trlr. now is a 110 hook up ran from my house about 150 ft. away.
The box in the trlr. has 1 100 amp brkr. 3 20 amps and 1 15 amp.
The trlr. has a/c lites and plugs, and I would like to use all the functions in the trlr. plus add a grinder and drill press along with other tools.
Will I have to run a large wire from the service panel 150' away @ house to a breaker panel to the trailer?
If so what size wire would I need?
What kind of problems would it be to run that far?
I hope this makes sense.
thanks

J. V. · 09-25-2009, 01:56 PM

Are you going to move it anymore, or is it going to stay where it is? What I am asking is, if you are going to move it, you want to wire it so you can just unplug it and go, but make sure you can connect it anywhere you take it, right?

menu item · 09-25-2009, 05:41 PM

I dont plan on movin it for some time.
If I need to trench all the way to it I will just put a panal near it on a post.
I think I might have to send line from my 200 amp panel @ house all the wat to trlr.
dont know

Code05 · 09-25-2009, 06:04 PM

So, you want to run a 100 amp feeder/wires to a panel, 150 feet away, onto a pole and then power the trailer off this panel, correct?

menu item · 09-25-2009, 06:59 PM

I dont know what I have to do.
All I have near the trlr now is a 110 outlet thats 20' from the trlr now.
Its 12/2 wire I think, that runs all the way to the house 150' away to house panel.(20amp brkr.)
I know I cant run a/c lites and shop stuff off that.
So the ? is.What size wire do I need to run from house panel to the panal in traler and could I somehow use the 12/2 wire from the outlet near trlr now and put both hot legs to one side of 100 amp brkr in trlr to run lites and a/c? or do I need big wire goin from panal on house to panal in trlr?
If so what size wire?

AllanJ · 09-25-2009, 09:16 PM

You can run 2 conductor cable (with ground) of any size you want from house to trailer and be able to use just lights and 120 volt equipment up to the number of amperes the wire takes.

You can run 3 conductor cable (with ground) of any size you want and be able to use 120 and 240 volt equipment up to the number of amps the wire takes.

The branch circuit breaker or breaker pair at your house's panel that serves this wire run must be correct for the wire you ran, not necessarily matching the main breaker that stays in the trailer panel.

Actually for 150 feet of run I would expect the maximum number of usable amps to be that of the next smaller size for example 8 gauge copper wire takes a 40 amp breaker but you should count on just 30 amps (which 10 gauge wire takes) before noticeable voltage drop occurs. The existing outlet box attached to the tree or wherever and hooked up with 12/2 cable will probably give you about 15 amps of 120 volts that you could split between the two hot legs of the trailer panel.

Install a ground rod outside and near the trailer panel. Connect it to the panel using a continuous (splice free) #6 copper wire.

MinConst · 09-25-2009, 09:26 PM

After reading this thread I must say this is not DIY project. At least get an Electrican over to the property, to tell you what to do.

Code05 · 09-25-2009, 10:12 PM

Quote:

Originally Posted by MinConst

After reading this thread I must say this is not DIY project. At least get an Electrican over to the property, to tell you what to do.

I disagree. I am an electrician and if the OP gets a permit and follows the instructions that AllenJ gave him he will be fine. There are some minor code issues involved here depending on which cycle the OP is on and what the final load calc. will be but a sub panel is certainly in the realm of DIY if the person is capable.

Code05 · 09-25-2009, 10:19 PM

Quote:

Originally Posted by menu item

could I somehow use the 12/2 wire from the outlet near trlr now and put both hot legs to one side of 100 amp brkr in trlr to run lites and a/c?

Quote:

Originally Posted by AllanJ

The existing outlet box attached to the tree or wherever and hooked up with 12/2 cable will probably give you about 15 amps of 120 volts that you could split between the two hot legs of the trailer panel.

You both lost me here.

These statements are confusing, what do mean?

menu item · 09-25-2009, 10:58 PM

What a web site!
The rtlr. has a4 wire feed 1 big blk., 1 big red, 1 big wht., 1 big grn.
I think what I need is to run that same wire from panel on house on a 100 amp brkr. from panel, bury it to code, and conect the colors goin into trlr.
It measures 220' from panal on hs. to pnl. on trlr.
Put 100 amp brkr. @ hse. and run big wire to trlr. to 100 amp at box in trler.
I need big cable from house to trlr.
Can I post pics on her?
If that makes sense Will panal to panel with big enough wire be cool @ that dist.?

menu item · 09-25-2009, 11:01 PM

I hear ya I always over complicte s...!
Thanks for puttin up w/me
And I should get an electrician here but im broke!

Code05 · 09-26-2009, 12:01 PM

Tell me about this cord . Twist lock?

AllanJ · 09-26-2009, 08:11 PM

RE: split between the two legs ...

I meant the current flow, not the pigtails and wire nuts.

(one extreme) Yes you could connect the single hot conductor of a 12 gauge 120 volt feed to both legs of the 240 volt panel.

Then if equipment served by one leg drew 10 amps when in use, and you had 15 amps available, then equipment drawing just 5 amps from "the other leg" at the panel could be in use at the same time.

Whereas with 3 wire cable and 240 volts, and 15 amps of current available, you would have 15 amps on one side of the line and an additional 15 amps on the other side of the line assuming 120 volt equipment.

(the other extreme) If you are sure you're going to use the trailer electrical system to its fullest, you would install a like breaker (100 amps) at your house panel. This requires at least #2 copper or "0" aluminum wiring. One size larger to assure all 100 amps with negligible voltage drop 220 feet away would be "0" copper "00" aluminum respectively.

menu item · 09-27-2009, 01:07 AM

100 amp @ hse. and "00" to trlr.sub panels 100 amp brkr.
I was worried about power drop @ that distance.
Thanks

menu item · 09-27-2009, 01:08 AM

I will see if it is twist in the morn.

09-25-2009, 12:36 PM	#1
menu item Newbie Join Date: Sep 2009 Posts: 12	elec. in const. trlr. Hi folks I have an 8'by 24' constr./office trlr. that has a 125/250x 50' cord that plugs in on job sites. The only power near the trlr. now is a 110 hook up ran from my house about 150 ft. away. The box in the trlr. has 1 100 amp brkr. 3 20 amps and 1 15 amp. The trlr. has a/c lites and plugs, and I would like to use all the functions in the trlr. plus add a grinder and drill press along with other tools. Will I have to run a large wire from the service panel 150' away @ house to a breaker panel to the trailer? If so what size wire would I need? What kind of problems would it be to run that far? I hope this makes sense. thanks

09-25-2009, 05:41 PM	#3
menu item Newbie Join Date: Sep 2009 Posts: 12	elec. in const. trlr. I dont plan on movin it for some time. If I need to trench all the way to it I will just put a panal near it on a post. I think I might have to send line from my 200 amp panel @ house all the wat to trlr. dont know

09-25-2009, 06:04 PM	#4
Code05 Member Join Date: May 2009 Location: Easton MD Posts: 1,840	elec. in const. trlr. So, you want to run a 100 amp feeder/wires to a panel, 150 feet away, onto a pole and then power the trailer off this panel, correct?

09-25-2009, 06:59 PM	#5
menu item Newbie Join Date: Sep 2009 Posts: 12	elec. in const. trlr. I dont know what I have to do. All I have near the trlr now is a 110 outlet thats 20' from the trlr now. Its 12/2 wire I think, that runs all the way to the house 150' away to house panel.(20amp brkr.) I know I cant run a/c lites and shop stuff off that. So the ? is.What size wire do I need to run from house panel to the panal in traler and could I somehow use the 12/2 wire from the outlet near trlr now and put both hot legs to one side of 100 amp brkr in trlr to run lites and a/c? or do I need big wire goin from panal on house to panal in trlr? If so what size wire?

09-25-2009, 09:26 PM	#7
MinConst Remodeler Join Date: Nov 2004 Location: Spring Hill FL. Posts: 436	elec. in const. trlr. After reading this thread I must say this is not DIY project. At least get an Electrican over to the property, to tell you what to do. __________________ Minichillo's Construction I will never leave you hanging! To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts. To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

elec. in const. trlr.