My house is 9 years old and has a 200 amp service. House is 170 feet from transformer on poll and has underground 4/0 XHHW cable. I got a quote of 6-10k for PPL to run a 200 amp service to my 40X64 poll barn that is another 150 feet behind the house. So no way in hell I'm paying that for a service that would be considered a commercial account anyways. So i need to tap off my house to power the barn and have some questions. PPL says i can upgrade the meter on my house to 400 amp but need to have an electrician check my wire. I see my wire is rated at 205 amps and i assume that is per leg giving me a 410 total. I do plan to have a large mill and lathe at some point so min i would like to go is 150 amp service to barn. Can anyone give me a rundown as to if my house can be upgraded to a 400 amp service and what kind of disconnect or splitter is needed at the meter base? I have called one electrician and he had no clue.
Power to new barn
- Thread starter BKB
- Start date
pattenp
Well-known member
You don't add the two legs together to get the total possible amp service. I assume your service cable is aluminum, so 4/0 is 200A. It may be possible to put a 150A sub feed from your 200A main panel. Actually I believe you could get by with a 100A feed.
wyliesdiesels
Well-known member
I'm with pattenp on this one. I bet u could get by with 100a feed to your shop! You could do all the work(trenching, conduit, wire pulling) and then leave the connections up to an electrician if u don't feel comfortable doing that! It would save u a lot. And I think before we go any further, u should let us know your location because if you're up in Canada, many of us can't help!
I'm in PA and the house has oil heat, oil fired hot water and central air. So most of the time there is little electrical draw on my service. My syncrowave 351 welder probably draws around 150 amps maxed out all on its own plus the 7hp compressor, 2 post lift, and possible CNC equipment i would feel better with 200 amp service. But with a stretched budget 100 or a 150 amp sub panel might half to do. Going to call the electrician that wired the house and see what they say.
Thanks
brian
Thanks
brian
pattenp
Well-known member
Your welder looks like the determining factor. If definitely requires some juice.
wyliesdiesels
Well-known member
wyliesdiesels
Well-known member
O wow! 
I'm guessing that it must be direct wired and u would have to use 1/0 cu or 3/0 al just to feed it! LoL I was just gonna give u the wire sizes for the feeder to your barn until u posted that! You're gonna need some FAT cable to feed the barn! Do u really need such a big welder? And what else will be running simultaneously with the welder? That will determine what size service u will need!
I'm guessing that it must be direct wired and u would have to use 1/0 cu or 3/0 al just to feed it! LoL I was just gonna give u the wire sizes for the feeder to your barn until u posted that! You're gonna need some FAT cable to feed the barn! Do u really need such a big welder? And what else will be running simultaneously with the welder? That will determine what size service u will need!
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theoldwizard1
Well-known member
They do make 400A meter socket that has dual lug output. Wire to the house would not have to change. Wire to the barn would come right off the second set of lugs on the meter base. This not considered a "sub panel", so only 3 wires need to be run to the barn. Barn does need proper ground rod(s) installed.
PPL and/or local inspector may require disconnect inside the base or immediately adjacent to the meter. Bases are are available with and without disconnects.
PPL may have to upgrade the feed to the meter base, but that is their problem. You need to verify you are getting proper voltage in the house when the welder is running at max.
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theoldwizard1
Well-known member
Only need 3 wires, you will need to put in seperate grounding rod(s) out at the new building. You need 2 hots and a neutral from your meter. I just did this same setup for my shop. From my meter i ran into a 200 amp square D disconnect box. From there i ran 120 ' of 2" conduit out to the shop and put in a 200 amp square D breaker box. I drove 2 10' long grounding rods in the ground and bonded one to the other and ran #4 solid copper in its own conduit into the breaker box. I then ran 2 runs of 4/0 wire and 1 2/0 wire. My 4/0 are my two hot leads for 220 and the 2/0 is neutral back to the grid and the seperate ground rods and #4 copper is the new mechanical ground. I also weld but am only on a 100 amp for the welder but also run a 7.5 hp quincy compressor and plenty of light and other equipment and havent had any issues at all. My main house feeder is 4/0 wire as well.
pattenp
Well-known member
My understanding is the service from the meter to the first disconnect box can be 3 conductors, but from the first disconnect box to the breaker panel it should be 4 conductors. The neutral and ground bonding is done in the disconnect box. I forget the details on this, but this is what I'm thinking.
theoldwizard1
Well-known member
My understanding also.
There is an exception for running 2 - 200A load centers directly off of a 400A meter socket/base.
theoldwizard1
Well-known member
Actual spec is 135A on single phase.
Code wise, a detached garage or shop should not be bonded to your homes ground. You can bond your disconnect by the meter with your homes ground but you cannot bond a detached building to a home. The shortest path to ground will always be taken, so if your building is 100 feet from your home and you bonded it to your home then the extra distance could be a issue. Code says detached garages or shops need its "own" 10' rod (actually says to use 2 or more) and space them 8' apart i do believe and bond one to the other and then run into your new panel. This way in a shortage or anything then the breaker will sense the short and trip much faster then if it was bonded 100' away or so. Plus you cannot have a ground wire in the same conduit as your power feeds.
theoldwizard1
Well-known member
Using this ampacity calculator and assuming XHHW copper wire you will probably need #2 for 150A and #4 for 100A off of the main.
If you want to go to a 400A meter and 200A in the barn, you will definitely have to upgrade the feed to the house.
If you want to go to a 400A meter and 200A in the barn, you will definitely have to upgrade the feed to the house.
theoldwizard1
Well-known member
And so starts another debate of the NEC "lawyers".
Pass the popcorn.
Remember, in the end, the only person you have to satisfy is the local inspector !
I was just passing on what i was told and what i had to do to make the inspector happy so i figured i would post all my stuff i just had done since it sounds identical to what the OP was wanting to due.
garelect
New member
1/0 copper for 150amp (thhn if in conduit) if run is longer than 100' ushould up size for voltage drop 4 wires to sub panel hot hot nuetral ground as well as 2 ground rods at least 6 ' apart
BigGMC
Well-known member
Are you in Canada? Alot of what you've posted is not true and/or inaccurate in the states.
This was the stuff i had to have when my inspector came out to check everything before i could button it all up. Dont know if it is different in certain areas but this is what was required for me in Indiana. What statements are not true??
pattenp
Well-known member
NEC actually says only one rod is needed if the resistance to earth is 25 ohms or less, or you can use a second rod if the resistance requirement can't be met. Also the rods need to be at least 8' long and if you use two then they are to be spaced no closer to each other than 6'. I'll pass the popcorn back now.
wyliesdiesels
Well-known member
What is your location? NEC code only requires 8' 1/2" rods and max #6cu for the GEC and can be run unprotected as long as it follows the contour of the building(no conduit needed). And its 3 wires to the first disconnect and then 4 after that!
That's how I understand it as well and how I've wired this scenario before. 3 wires to first disconnect, 4 wires after that!
So much wrong here aside from it not being US code!
First bold text(I'm too lazy tonight to copy and paste the html code for quotes over and over): you contradicted yourself!
2nd: US code is 2 8' rods and spaced 6' apart
3rd: Ground rods have ABSOLUTELY NOTHING to do with a breaker tripping to clear/interrupt line to line shorts! And can u give us a code cite that says an EGC(aka ground wire) can not run in the same conduit as the hot legs? Never heard of this! Many SE cables have the EGC bundled with the hot legs!
(U just gotta love the novices!)
LMAO
wyliesdiesels
Well-known member
Wow! Your AHJ must have special rules!
BigGMC
Well-known member
It's like a grenade...... I simply pulled the pin and.......... 
Like i said this is just what stuff i had to do to make my inspector happy. As for the rod length i didnt mean they had to be 10' and 8' apart i could just remember him telling me they needed to be "x" amount away from each other and bonded together. As for the ground not being in with the same conduit. I thought this was bs as well because most feeder wires have a ground in them so i dont know why i had to run in a seperate 1/2" conduit.
Sorry if everything was not 100% accurate i was just explaining what i just had to do and what my inspector made me do before i got passed. Just tried to explain my install since its basicly the same as the op is wanting to do.
Sorry if everything was not 100% accurate i was just explaining what i just had to do and what my inspector made me do before i got passed. Just tried to explain my install since its basicly the same as the op is wanting to do.
wyliesdiesels
Well-known member
Well either a: your AHJ has VERY special rules, b: the inspector doesn't know code, c: he thinks Indiana is in Canada, d: all of the above. And....*pass the popcorn back to pattenp*...here ya go!