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Topic: 30 or 50 amp service 350 foot from home

Posted By: sanfordandwife on 02/09/11 03:51pm

I am wanting to run either 30 or 50 amp service for my RV straight out from my meter box at my home what size wire will I need to run 350 foot? I will not be using a air conditioner very often. I am putting in a new breaker just for this. Any help would be appreciated. Thanks Sanford


Posted By: MacRoadie on 02/09/11 04:00pm

sanfordandwife wrote:

I am wanting to run either 30 or 50 amp service for my RV straight out from my meter box at my home what size wire will I need to run 350 foot? I will not be using a air conditioner very often. I am putting in a new breaker just for this. Any help would be appreciated. Thanks Sanford


Here is a handy calculator you can use:

Voltage Drop Calculator


Probably be your best bet to run 1/0 copper if you're not planning on running more than the A/C and looking at a 30 amp circuit. 350' is a pretty good run.

I'd let others weigh in first though.


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Posted By: katfish on 02/09/11 04:01pm

Site

Check out the site above to see it it will help U..


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Posted By: Art D on 02/09/11 04:44pm

I would use #4 awg.


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Posted By: MacRoadie on 02/09/11 04:43pm

todouble wrote:

If your running a 30 amp service your gonna need atleast #6awg. If you want a 50 amp service your gonna need atleast a #4awg. Your aloud 10% voltage flucuations and these would keep you about 7-8% below which is still acceptable. Goodluck


It all boils down to cost. You can increase conductor size and eliminate most of the drop, but it comes at the cost of more expensive conductors, which might be pretty sizeable over 350' (1,350') total.


Posted By: todouble on 02/09/11 04:40pm

If your running a 30 amp service your gonna need atleast #6awg. If you want a 50 amp service your gonna need atleast a #4awg. Your aloud 10% voltage flucuations and these would keep you about 7-8% below which is still acceptable. Goodluck






Posted By: katfish on 02/09/11 05:41pm

deereone wrote:

You might want to check with your electric company and see if they will run another drop from their pole to a pole near your RV. In my case they did it at no charge. And it saved me running 400' of 50 amp wire. I do have a second meter on that pole and I had to purchase the panel with breaker to mount on the pole.


That is what I did, it is cheaper to pay the user fee for the meter than what it was going to cost for the wire run...


Posted By: smkettner on 02/09/11 06:08pm

MacRoadie wrote:

smkettner wrote:

This calculator shows #4 for 30a & 350'
#6 is good for 20a at that distance


Funny, I tried that one and 30A at 350' comes out to a #1, not #4.
Did you use 240v?


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Posted By: smkettner on 02/09/11 04:50pm

I would do the size calculation based on 30 amps. Get a double 30a breaker and wire it to the standard NEMA 14-50R to plug in direct. Basically for the price of one more wire you get twice the power of standard 30a RV service.

katfish wrote:

Site

Check out the site above to see it it will help U..

This calculator shows #4 for 30a & 350'
#6 is good for 20a at that distance


Posted By: MacRoadie on 02/09/11 05:20pm

smkettner wrote:

This calculator shows #4 for 30a & 350'
#6 is good for 20a at that distance


Funny, I tried that one and 30A at 350' comes out to a #1, not #4.

Like I said, the problem is cost. #6 is about $1.25 a foot, #4 goes for about $1.75 a foot and 1/0 is at $3.00 per foot.

Plus, you're gonna need to run a hot, neutral, and ground so you really need 1,350' of cable. Even using #4 for the hot and neutral, you're into the project for almost $1,300 just in conductor, not to mention all that conduit. You're probably going to be in it for well over 2 grand by the time you add in breakers, receptacle, a pole at the remote site, a weatherproof pull box, etc.

You sure you need it that badly? Getting your service provider to give you a new drop might make more sense...


Posted By: deereone on 02/09/11 04:47pm

You might want to check with your electric company and see if they will run another drop from their pole to a pole near your RV. In my case they did it at no charge. And it saved me running 400' of 50 amp wire. I do have a second meter on that pole and I had to purchase the panel with breaker to mount on the pole.


Posted By: Gdetrailer on 02/09/11 07:26pm

Why 350 ft?

Perhaps it would be better to locate your RV closer, say 100 ft away. This would dramatically reduce the required size of wire for satisfactory operation of your remote power. In turn reduce the costs over all.

Although your electric Co will be more than happy to go with a second meter, this actually over the long run could cost you far more than upsizing the wire or moving the RV closer. Some utilities actually will charge you a separate bill for your second meter. In this they will DUPLICATE your basic costs and this duplication on your second bill could cost you $20-$40 per month even if you are not using the power (RV disconnected from shore power).

If you go with this then you better contact your local power co and find out just how they bill separate meter/service BEFORE you start with having it installed.


Posted By: Fiver Captain on 02/09/11 04:59pm

You need to do as suggested. Look at the voltage drop calculator that MacRoadie suggested. There's no way 4 or 6 is going to give you the performance you're looking for. 350 ft. is an exceptional secondary run. As suggested, 1/0 will give you negligable voltage drop especially when the AC compressor kicks in. The biggest problem you might have is making sure the breaker lugs will accept 1/0 cable. This is assuming you use copper. If you run aluminum, you will have to increase the cable size accordingly. Also, as suggested, ask your power company what they would offer as far as another service drop. If they will run it free (doubtful in todays economy), then all you would have to pay would be the minimum monthly fee depending on how you use the service.

And yes, I do have 34 years of experience in the electrical field.






Posted By: Hank MI on 02/09/11 05:42pm

It doesn't matter what you plan to run, 1 AC, 2 AC, microwave, etc. You must use the calculator and size the wire accordingly. If you have a 30 amp connector then the wire must be sized for it, same for 50 amp. If you use conduit then that will increase the wire size, didn't look at the calculator to see if it accounts for this.

A new drop and meter is definitely cheaper.


Posted By: TXiceman on 02/14/11 06:45am

To save some $$$$ if you can find smaller wire for less money, is to double up and runn two sets of wire in parallel.

You might also look at running the wires in aluminum and use the proper transition barriers.

Ken


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Posted By: Rvpapa on 02/14/11 10:28pm

Check the legality for your area but you might be able to run two wires and drive a ground rod at the far end.
Art.


Posted By: Golden_HVAC on 02/09/11 09:29pm

Hi,

I am living in a site about 300' from my electric meter, and it is served with #8 wire. I get about 1 volt drop per amp that I am using, so if I am drawing about 12 amps running the microwave, my input voltage drops from 120 to about 109. If I run my air conditioner, then voltage drops to about 107.

What I do in the summer is use a 12 volt booster, and this cost is about $300.

So I have 132 volts most of the summer, and 120 when I run the A/C. I do not plug in my refrigerator to the boosted power, because the voltage is to high for running a heater. I plug in the refrigerator to another receptical (not the receptical behind the refrigerator, but on the power post) so it only sees 118 volts.

My TV and everything else works fine at 132 - 108 VAC.

My suggestion? Install #2 wire if you like, and it will give a very minimal voltage drop. But if that is to expensive, then #6 wire will work fine if you are using a voltage booster. Because the wiring is rated at the amperage for a 50 amp system, you might as well install a 50 amp service.

You will also be able to run other things with the 50 amp service, such as area lights, and other things.

Fred.


Posted By: Golden_HVAC on 02/13/11 12:25pm

sanfordandwife wrote:

Wheather I run 30 or 50 amp. I still need to run #2 wire so the only thing I save is one wire. 50 amp 3 wires plus ground and 30 amp 2 wires plus ground. I am going to stay on this property for 4 months a year its at Pismo Ca. RV parks are charging $1100 a month. I figure if it cost me $4000 to get the hook ups I would be money ahead on the secound year. I might look in to some kind of solar. Thanks again for all you comments.


Hi,

You can also run #6 wire, and use a smaller conduit, and then buy a voltage booster for about $315, and save money overall.

Fred.


Posted By: smkettner on 02/10/11 03:26pm

sanfordandwife wrote:

Wheather I run 30 or 50 amp. I still need to run #2 wire so the only thing I save is one wire. 50 amp 3 wires plus ground and 30 amp 2 wires plus ground. I am going to stay on this property for 4 months a year its at Pismo Ca. RV parks are charging $1100 a month. I figure if it cost me $4000 to get the hook ups I would be money ahead on the secound year. I might look in to some kind of solar. Thanks again for all you comments.


Not exactly. 30a will have less voltage drop and will be fine with smaller wire.

You can install a "50amp" 4 wire circuit but size it at 30 amps. This will give 30a per leg and twice the power of a regular 120v 30a RV circuit. This will allow plenty of power using smaller wire. This gets you into #4 wire instead of #2 and will save some real money with no loss of functionality. OK maybe you can't run two airconditioners, washer/dryer, water heat, microwave, and hair dryer at the same time. But still it gives 7200 watts available.

Honestly I think you would be fine at #6 as the average draw will probably be less than 20 amps per leg.

* This post was edited 02/10/11 03:34pm by smkettner *


Posted By: Bumpyroad on 02/10/11 08:37am

If you are not going to run the ac very often, what is the difference in cost between 30 amp and 50 amp? I'd go with 30 myself.
bumpy






Posted By: wp6529 on 02/14/11 09:19am

TXiceman wrote:

To save some $$$$ if you can find smaller wire for less money, is to double up and runn two sets of wire in parallel.

You might also look at running the wires in aluminum and use the proper transition barriers.

Ken


Parallel conductors aren't allowed by the NEC in small sizes, paralleling is only allowed above something like 350MCM wire size if I recall.

Personally, for such a long run in conduit I'd be tracking down a couple used 15KVA 240/480 transformers to step up the voltage for the long run and then drop if back down. Double the voltage, half the current.


Posted By: diveman52 on 02/14/11 07:52pm

Wow answers allover the place. To bad only about two or three people know what they are talking about the REST ARE FULL OF IT!!!!!
Oh ya #2 Copper will limit the voltage drop to just under 3% as recommended by NEC for a 30 amp service.


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Posted By: Dutch_12078 on 02/15/11 07:02am

Rvpapa wrote:

Check the legality for your area but you might be able to run two wires and drive a ground rod at the far end.
Art.

I'm not aware of any section of the National Electrical Code that would permit that.


Dutch
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Posted By: christopherglenn on 02/09/11 09:28pm

Out in PG&E (California) service areas it is 1k per pole.

Maybe #4 and an autoformer?


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Posted By: sanfordandwife on 02/10/11 06:39am

Thanks to everyone who responded. I found out that it was only 300 ft that I had to run. I check the chart and decided that I would run #2 wire and go ahead with the 50 amp. service. Thanks again for the heip. Sanford


Posted By: sanfordandwife on 02/10/11 02:21pm

Wheather I run 30 or 50 amp. I still need to run #2 wire so the only thing I save is one wire. 50 amp 3 wires plus ground and 30 amp 2 wires plus ground. I am going to stay on this property for 4 months a year its at Pismo Ca. RV parks are charging $1100 a month. I figure if it cost me $4000 to get the hook ups I would be money ahead on the secound year. I might look in to some kind of solar. Thanks again for all you comments.


Posted By: george48 on 02/10/11 03:02pm

Hank MI wrote:

If you use conduit then that will increase the wire size,


How is that a reason to increase wire size? The only purpouse the conduit has it to protect the wire.


Posted By: vcallaway on 02/10/11 07:33am

#2 wire @ $2.44 per ft (my local price) X 320 ft (don't forget ups and downs) X 3 = about $2,350 in wire alone.

I think I would put in a pole mount solar system and use it to shade the RV.


1989 Honey Maxum



Posted By: Hank MI on 02/10/11 05:07pm

george48 wrote:

Hank MI wrote:

If you use conduit then that will increase the wire size,


How is that a reason to increase wire size? The only purpouse the conduit has it to protect the wire.


There is always resistance in wiring. The larger the gauge the less resistance and resistance means heat. In overhead, underground and interior wiring any heat buildup due to resistance is easily dissipated by the surrounding air or earth. When the wires are enclosed in conduit the heat cannot dissipate as easily. It can build to the point of melting insulation and causing a fire.

Not a concern in the typical short runs, low amperage wiring you would normally deal with in a house. He was talking about 350', 50 amp service. At that point it needs to be taken into consideration. There are wiring gauge calculators that will factor in the use of conduit if required.


Posted By: Hank MI on 02/13/11 01:03pm

Golden_HVAC wrote:

sanfordandwife wrote:

Wheather I run 30 or 50 amp. I still need to run #2 wire so the only thing I save is one wire. 50 amp 3 wires plus ground and 30 amp 2 wires plus ground. I am going to stay on this property for 4 months a year its at Pismo Ca. RV parks are charging $1100 a month. I figure if it cost me $4000 to get the hook ups I would be money ahead on the secound year. I might look in to some kind of solar. Thanks again for all you comments.


Hi,

You can also run #6 wire, and use a smaller conduit, and then buy a voltage booster for about $315, and save money overall.

Fred.


Doesn't work. 50 amp 240v is 12,000 watts of power. If #6 wire drops the voltage to 200v then you would need 60 amps to produce 12,000 watts of power, #6 won't handle it. The voltage booster can increase the voltage but will require more amps coming in then going out. It doesn't generate power and power is volts X amps, can't get more power out than you put in.

As suggested 1/0 aluminum will handle it and will be cheaper than copper wire.


Posted By: garry1p on 02/23/11 05:57pm

The real queation is how much power at the drop do you really need????

Full 30amp then I suggest a new power drop by the power company and be done with it.

For me 230 ft 30amp... I live in the country (no problems with codes) so I did run 10 gage overhead in parallel while I can run the rear 1300BTU AC I don't.

I really only need power for converter and now amp stuff.


Garry1p


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Posted By: smkettner on 02/20/11 04:56pm

Allworth wrote:

RV's do not EVER use 240Volt service. Split phase 120Volt unbalanced load with 50Amps on each phase.

NOT 240 Volts.

So, yes, calculate as a 120V circuit.


So with an air conditioner on L1 and a second same size air conditioner on L2 how many amps are in the neutral? Looks like 240 to me.

Just saying that most single items are about 10 amps max. You don't need that much wire (2/0) for 10 amps. As you load the RV up the appliances use both sides(L1,L2), reducing the neutral current and in effect the RV is "using" 240 volts even if the individual loads are 120v.

Or how about what voltage would be used to calculate voltage drop if you were to wire a nema 14-50r and the purpose was unknown?

* This post was edited 02/20/11 05:12pm by smkettner *


Posted By: smkettner on 02/19/11 09:09pm

So a 50a 240/120 volt circuit (nema 14-50R) is calculated at 120v?


Posted By: smkettner on 02/19/11 07:51pm

bradley455 wrote:

here my calculations at 600 feet remember this is to the camper and back (alum wire)

1/0 is 112.9 volts at 30 amps 7.1 volt drop
2/0 is 114.5 volts at 30 amps 5.5 volt drop
3/0 is 115.5 volts at 30 amps 4.5 volt drop
4/0 is 116.4 volts at 30 amps 3.6 volt drop
...


katfish wrote:

Site

Check out the site above to see it it will help U..


The link seems to think #2 aluminum is fine on a 240v 30a circuit.


Posted By: Bumpyroad on 02/19/11 03:54am

bradley455 gives a good reason why the dual 30 amp or just 30 amp service makes sense to me. unless you are talking about permanently living in it in the desert and running 2 ACs, well it's your money you are wasting.
bumpy


Posted By: Bumpyroad on 02/20/11 01:03pm

Allworth wrote:

RV's do not EVER use 240Volt service. Split phase 120Volt unbalanced load with 50Amps on each phase.

NOT 240 Volts.

So, yes, calculate as a 120V circuit.


so the big boys with huge all electric equipment, dryers, etc. don't have any 240 V appliances. that is contrary to previous posts.
bumpy


Posted By: Allworth on 02/20/11 12:17pm

RV's do not EVER use 240Volt service. Split phase 120Volt unbalanced load with 50Amps on each phase.

NOT 240 Volts.

So, yes, calculate as a 120V circuit.


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Posted By: Allworth on 02/19/11 07:41pm

Hank,

They were talking about using an earth ground instead of the wire ground.


Posted By: Allworth on 02/16/11 02:02pm

NO EARTH GROUND!!!

Never.


Posted By: hbarker on 03/02/11 09:09pm

Ouch,, some one told me CA stands for Cost Associated.

christopherglenn wrote:

Out in PG&E (California) service areas it is 1k per pole.

Maybe #4 and an autoformer?



Posted By: 69gp on 02/20/11 08:16pm

you cannot have more than a 3% drop on the total run of the circuit.
There are few ways to help get the voltage there, one being to use buck boost transformers to boost it when leaving the house. another option is can you run a line overhead?.


Steve B
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Posted By: bradley455 on 02/18/11 10:27pm

omg i cant not believe some of these answers.... im a journeyman electrician for almost 20 years and you have to have a 3 wire system to that camper (hot neutral ground). otherwise you will start burning up your campers equipment , it will be searching for a neutral or ground and you will lose your ac ,tv anything electronic inside.... In any circuit, there are two conductors, and there is a voltage drop in each conductor.
Since the two conductors are usually equal in length, the distance
from source to load (as the conductors are routed) is usually doubled to get a total length that is used for determining the resistance to be used in the calculation. so you will have a combine total of 600 feet .as for the distance yes you will have a voltage drop at 300 feet( 600 feet total ).thats quite a run at any size of wire.. rule of thumb is no more then 3 percent of the voltage drop is allowed.

i would run alum direct burial (cost of copper will set you back thousands of dollars) .( check your local electrcial codes) you do not need conduit in the ground only where it comes out of the ground... now for the size you are looking at at a 1/o to 4/0 size wire . this is for a 30 amp load ..if you go to 50 amps your wire size is going to be quite big....

here my calculations at 600 feet remember this is to the camper and back (alum wire)

1/0 is 112.9 volts at 30 amps 7.1 volt drop
2/0 is 114.5 volts at 30 amps 5.5 volt drop
3/0 is 115.5 volts at 30 amps 4.5 volt drop
4/0 is 116.4 volts at 30 amps 3.6 volt drop

as you can see your wire size is getting bigger as you get closer to 120 volts and so will cost .....
you will also have to have a disconnect at that area by your camper and another ground rod plus your ground wire . if you can i would add another meter right next to that camper less problems with voltage drops and cost issues..

another rule of the trade ,copper size wire vs alum wire size

if you use copper wire its usually 2 wire sizes smaller than alum ,
because alum has a lot more resistance .

if you use alum wire its usually 2 wire sizes bigger than the copper wire.

hope this helps if you have any more questions please ask or ask a qualified electrical contractor near you.. your rv s electrical is nothing you want to mess around with its expensive to fix....

* This post was last edited 02/25/11 09:32pm by bradley455 *


Posted By: bradley455 on 02/19/11 08:34pm

We are not using 240 volt to feed the camper we are using 120 volts. If you are using 240 volts for your calulations at 240 volts would be only good for a 240 voltage load not 120


Posted By: bradley455 on 02/20/11 04:21pm

yes you are right there are no 240 volt loads in a rv..

* This post was edited 02/20/11 04:43pm by bradley455 *


Posted By: bradley455 on 02/26/11 08:44am

i think you just need to have a new line from the power company set by your trailer ,it would solve alot of issues


Posted By: bradley455 on 02/20/11 08:17pm

the ground rod does not does not qualifie as a earth ground on a branch circuit only on the main service.................

not to start a fight but i do not agree with this post from smkettner

which reads as follows

"Just saying that most single items are about 10 amps max. You don't need that much wire (2/0) for 10 amps. As you load the RV up the appliances use both sides(L1,L2), reducing the neutral current and in effect the RV is "using" 240 volts even if the individual loads are 120v."
quotaed from smkettner

you are correct sort of, we do not need this size for the current draw or amps you need this wire for the voltage drop.......

a smaller wire has more resistance then a larger wire, more resistance in the wire causes voltage drops and high temps in that wire . so we need a larger wire to increase electron flow or voltage. its like a garden hose, 1/2 inch vs 3/4 you get more flow out of the 3/4...

at 600 feet if you dont have the right size wire you will not have the correct voltage at that camper and will have what they call as a " brown out" or low voltage which will cause massive failures of the ac and electronics..

this was a calculation for a question that was ask.. 300 feet from house 120 volt 30 amp load and direct burial alum wire

buck boost transformers have to sized correctly to the load and are not cheap either. i would not use one in this application they are mostly design for machines right next to the voltage source at not so far away . again you would have to deal with a voltage drop and could burn up the coils inside of that transformer...

running a overhead line from the house does nothing ,yes conductors in free air can be rated for more amps because of the free air around them , but still would have to be rather large at that distance putting them in a conduit is another issue you can only fill the conduit up to 80 percent fill and only load them to 80 percent at 75 c rating..

one more thing about over head lines is support , poles have to be place into the ground no more than 100 feet apart maybe even less and you would have to have clearance over certain item driveways have to be 18 feet or swimming pools all sort of stuff.

the original question was base off of 120 volts 30 amp service,not a 50 amp hook up...if you go to 50 amps the wire size goes up really big being at the distance requested its almost to costly to do...thats why it was suggested in a previous post and i agree to locate a new service next to this camper from the power company..less mess and cost...


brad
journeyman electrician for 20 years in industrial commercial residential

* This post was last edited 02/20/11 08:34pm by bradley455 *


Posted By: Hank MI on 02/20/11 05:53pm

Allworth wrote:

Hank,

They were talking about using an earth ground instead of the wire ground.


I think an 8' ground rod qualifies as an earth ground and that was code when I installed the electric service.


Posted By: Hank MI on 02/17/11 06:38am

Allworth wrote:

NO EARTH GROUND!!!

Never.


I ran 50 amp service to a gazebo/hot tub. It was a requirement to have an 8' ground rod attached to the breaker panel inside the gazebo.


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