# Thinking about changing from 100 to 200 amp



## watcher (Sep 4, 2006)

I'm having problems with the lines from the meter box to my inside breaker box and I have decided the best thing to do is just replace it. We are going to add on to the trailer in the next year or so, therefore I'm thinking I may as well change from the 100 amp service we have now to 200 amp. Now the questions.

What size wire do I need for 200 amp service? I have been told 4-4-4-2 service line is used for it but I want to make sure before I spend the money to buy it.

Also what size conduit would be the minimum I should use to run it?


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## wharton (Oct 9, 2011)

Assuming that you have to comply with the electric utility's requirements, they will tell you what you need for wire, pipe, and meter base requirements. As for the wiring from the meter base to the service panel, if using aluminum wire the correct wire size for the two hot wires is 4/0 and the neutral would be a 2/0. At that point (typically) there would be no ground wire. All of these answers are highly dependent on local utility requirements, and most have all the info. and drawings of proper installations, online. In my area the pipe from the meter to panel can be 2", and a mast from the meter up to the point of attachment needs to be 2-1/2" ridged, or IMC. In many other areas 2" is fine for a mast. 
Don't forget that you cannot typically upgrade a service from 100-200 amps without replacing everything, including the meter, mast, panel, etc..... With new breakers, it's nothing to hit $1000 in parts alone.


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## watcher (Sep 4, 2006)

wharton said:


> Assuming that you have to comply with the electric utility's requirements, they will tell you what you need for wire, pipe, and meter base requirements. As for the wiring from the meter base to the service panel, if using aluminum wire the correct wire size for the two hot wires is 4/0 and the neutral would be a 2/0. At that point (typically) there would be no ground wire. All of these answers are highly dependent on local utility requirements, and most have all the info. and drawings of proper installations, online. In my area the pipe from the meter to panel can be 2", and a mast from the meter up to the point of attachment needs to be 2-1/2" ridged, or IMC. In many other areas 2" is fine for a mast.
> Don't forget that you cannot typically upgrade a service from 100-200 amps without replacing everything, including the meter, mast, panel, etc..... With new breakers, it's nothing to hit $1000 in parts alone.


My system is strange, to me any way. The power company line comes into the meter box then directly into a breaker box on the pole the meter is on. My feeder line runs from that breaker box to another breaker box in the trailer. The breaker box on the pole is already a 200 amp box but the box in the trailer is only 100 amps therefor I could only run 100 amp rated wire from the pole to the trailer. I'll have to ck with the electric company but IIRC, when we put the trailer in 200 amp was the smallest service they provided.


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## wharton (Oct 9, 2011)

watcher said:


> My system is strange, to me any way. The power company line comes into the meter box then directly into a breaker box on the pole the meter is on. My feeder line runs from that breaker box to another breaker box in the trailer. The breaker box on the pole is already a 200 amp box but the box in the trailer is only 100 amps therefor I could only run 100 amp rated wire from the pole to the trailer. I'll have to ck with the electric company but IIRC, when we put the trailer in 200 amp was the smallest service they provided.


 Ah, that makes things a lot clearer. you have a trailer service. In my experience, you "own" everything from the load side of disconnect on the pole outward to the trailer. So, in this case you need four wires to the trailer, two hots ,a neutral and a ground. The trailer can get a new 200 amp/40 circuit panel, and the grounds and neutrals stay electrically separate at the new panel, as it is technically a "sub-panel" with the disconnect on the pole being your "service disconnect". If you need pipe and wire sizes, I can look it up tonight. Good luck.


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## watcher (Sep 4, 2006)

wharton said:


> Ah, that makes things a lot clearer. you have a trailer service. In my experience, you "own" everything from the load side of disconnect on the pole outward to the trailer. So, in this case you need four wires to the trailer, two hots ,a neutral and a ground. The trailer can get a new 200 amp/40 circuit panel, and the grounds and neutrals stay electrically separate at the new panel, as it is technically a "sub-panel" with the disconnect on the pole being your "service disconnect". If you need pipe and wire sizes, I can look it up tonight. Good luck.


Always helps when someone gives all the info doesn't it? 

I'm 99% sure I need 4-4-4-2 wire. I want, but am not require, to use conduit this time due to the fact I've had two buried wires break due to water entering the waterproof insulation. One was a 240V line to my pump and the other is one of the 120V lines from the meter to the trailer. 

I have a possible line on some 3" conduit which I'm sure is bigger than needed but I might be able to get it for 1/3 to 1/2 the new price. Is there any problem with using conduit which is over-sized?


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## simi-steading (Sep 27, 2012)

I'm glad you started this thread.. I'm in the same boat, but not in a trailer.. 

I was wondering about the meter if it had to be changed, but I have a strange setup too..

Wire into the meter.. just hanging loose on the house into the meter.. then right below the meter is a disconnect box with a single large breaker in it...

The funny thing, the meter and that disconnect is on the north outside wall of the house, and the breaker box is on the west facing wall inside the house, maybe 25 feet or so from the meter... I haven't looked to see what kind of wire is between the disconnect and the breaker box.. or how it's run.. 

I wonder if I would still have to have the power company come out and swap anything on their end... Guess I just need to call... 

But then I'm afraid of triggering bells with them.. I can replace the breaker box myself, and since I've got the disconnect... wellllll......


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## MushCreek (Jan 7, 2008)

Be careful of your terminology when you buy your wire. You want 4/0-4/0-4/0-2/0, not 4-4-4-2. 4 gauge wire is not the same as 4/0 (four-ought, in the trade). There's a big difference in price as well!


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## Spysar (Mar 30, 2013)

watcher said:


> Always helps when someone gives all the info doesn't it?
> 
> I'm 99% sure I need 4-4-4-2 wire. I want, but am not require, to use conduit this time due to the fact I've had two buried wires break due to water entering the waterproof insulation. One was a 240V line to my pump and the other is one of the 120V lines from the meter to the trailer.
> 
> I have a possible line on some 3" conduit which I'm sure is bigger than needed but I might be able to get it for 1/3 to 1/2 the new price. Is there any problem with using conduit which is over-sized?


You need 4/0, not #4 wire. If you use bigger conduit, you will have to see how big a conduit your meter can, and panel with accept.


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## a'ightthen (Mar 17, 2012)

watcher said:


> Always helps when someone gives all the info doesn't it?
> 
> I'm 99% sure I need 4-4-4-2 wire. I want, but am not require, to use conduit this time due to the fact I've had two buried wires break due to water entering the waterproof insulation. One was a 240V line to my pump and the other is one of the 120V lines from the meter to the trailer.
> 
> I have a possible line on some 3" conduit which I'm sure is bigger than needed but I might be able to get it for 1/3 to 1/2 the new price. Is there any problem with using conduit which is over-sized?


 Bigger conduit is fine ( usually) .... 4-4-4-2 @ 99% sure? On 200 amp service? Check smoke detectors and insurance is my best advice if you follow through with that for it is all wrong.


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## farmrbrown (Jun 25, 2012)

http://www.mjobee.com/projects&news/NEC Art 310.15.pdf

2/O for copper, 4/O for aluminum.

NEC 31O.16


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## watcher (Sep 4, 2006)

a'ightthen said:


> Bigger conduit is fine ( usually) .... 4-4-4-2 @ 99% sure? On 200 amp service? Check smoke detectors and insurance is my best advice if you follow through with that for it is all wrong.


Down here they call it 4442 mobile home line. I guess they don't want to say all those "oughts"


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## wharton (Oct 9, 2011)

watcher said:


> Down here they call it 4442 mobile home line. I guess they don't want to say all those "oughts"


Yea, that could get confusing. a three 4/0 and a 2/0 piece of service cable barely fits in a 2" conduit. A piece of 4-4-4-2 aluminum sub-panel feeder can be slid into a 3/4" conduit.


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## Sawmill Jim (Dec 5, 2008)

Here i have always used three 3/0 copper i just like it .Inspectors will let you go over code but not under code .


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## cab (Dec 20, 2005)

Be aware that the size conductor you need depends on two things: the max current you plan to run through it (200 amps) and the DISTANCE it will run. Any cable has resistance and will drop the voltage, the longer, the greater the drop. You need to make sure the conductor is sized for both amps and length so you don't drop too much voltage. I think no more than a few percent is recommended. Talk to an electrician.


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## wharton (Oct 9, 2011)

cab said:


> Be aware that the size conductor you need depends on two things: the max current you plan to run through it (200 amps) and the DISTANCE it will run. Any cable has resistance and will drop the voltage, the longer, the greater the drop. You need to make sure the conductor is sized for both amps and length so you don't drop too much voltage. I think no more than a few percent is recommended. Talk to an electrician.


 Good information, except the part about using the "max current you plan to run through it (200amps)" You base voltage drop calculations on the actual load being used, which is not ever going to be 200 amps in this case. Generally doing proper voltage drops calculations involves many factors, everything from location of run, (free air overhead, direct burial, etc) number of conductors, wire material, insulation designation, and so on. Typically, 200 amp service cable feeding residential panels does not get involved with significant voltage drop. As a seat of the pants rule. If you have a heavy load, are using the proper gauge wire to start out with, and your distance from the breaker to the load is getting close to 175' you probably need to address voltage drop.


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## Robotron (Mar 25, 2012)

Also beware of the connections can have a max wire size. Your not allowed to trim strands to make it fit. Lots of details to check.


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