220 ft run for 100 AMP service

[minytrker]

I originally was getting a separate 200 amp service put in but the electric company wants to much so I am going to run 100 amp service off my main 200 amp service for my house.

What size wire and pipe do I need to run 100 amp service 220 ft under ground?

 

[sberry]

You need 100?

 

[mike93lx]

2-2-2-4 MHF should get you 90a,but not sure on distance. http://www.garagejournal.com/forum/showthread.php?t=44176

 

[2Big2Ride]

Our estimate was the reverse, a little over twice the cost to run +/- 180' 90A feed from the house to the shop than install a new 200A service for the shop. ...cuz the back corner of the shop was about 25' from the transformer.

 

[wyliesdiesels]

I originally was getting a separate 200 amp service put in but the electric company wants to much so I am going to run 100 amp service off my main 200 amp service for my house.

What size wire and pipe do I need to run 100 amp service 220 ft under ground?

What are the loads?

How many people?

2-2-2-4 MHF should get you 90a,but not sure on distance. http://www.garagejournal.com/forum/showthread.php?t=44176

Not at 220'

For 100a at 220' with 3.6% voltage drop 1/0 al will work. Or 2/0 al to keep voltage drop at 3%.

If u can get by with less capacity then wire can be smaller.

Need to know loads first.

 

[minytrker]

Just myself 99% of the time. Have typical small shop stuff.
220v:
2 post lift
TIG
MIG
Air compressor (dont use much)
Air Conditioner (doesnt get run 24/7)

110:
MIG
Lathe
LED Lights
Golf cart charger

 

[theoldwizard1]

SWAG - 60A service would be adequate as long as you are NOT running the lift, TIG, MIG, compressor and A/C SIMULTANEOUSLY ! 2 at the same time would be no problem. The 3rd one starting up could be an issue. Turn off the compressor or the A/C when running the lift pump.

 

[minytrker]

I would hate to be that close where if 3 cut on it would trip or overload. I definitely couldn't see turning off the AC everytime to use lift and cutting AC back on, not very practical to me.

 

[sberry]

You wouldn't need to turn off AC but its pretty easy to wait a minute to do other heavy work if the air comp is running, I have done several of these with a 60 breaker very similar and never had a trip, one Bud work 30 yrs in a similar garage, kran 20A AC on occasion and a 5 hp comp.

 

[mike93lx]

My last house was 60a service with an electric dryer, electric range, fridge, upright freezer, 3 sump pumps and window ac's. Never did the main pop. I think you guys are worrying too much.

 

[brownbagg]

how often is your welder going be burning wide open. welder dont use must energy on common stuff

 

[polexican23]

Just run #2 wire, why cause that is what I am doing.

 

[mike93lx]

Just run #2 wire, why cause that is what I am doing.

Great advice right here

 

[MagKarl]

Have you priced the wire yet? If you want 100A, then go for it. Not worth penny pinching on the feeder in my opinion.

 

[minytrker]

I was trying to find out what size wire so I can price it. I dont have a choice though, I need to run permanent electricity out there.

 

[pattenp]

I think your best bet is to use 2/0 aluminum Mobile Home Feeder (MHF). It needs to be overcurrent protected to no more than 100A and that will give you what you want and will be no problem at the 220 feet. Here's where it can be purchased online....
https://www.wireandcableyourway.com/Mobile-Home-Feeder/

 

[Roberts210]

Have you priced the wire yet? If you want 100A, then go for it. Not worth penny pinching on the feeder in my opinion.

What he says.

 

[wyliesdiesels]

Just run #2 wire, why cause that is what I am doing.

220' is too far for 90a on #2 al

 

[sberry]

Terminations may be a problem with larger conductors.

 

[theoldwizard1]

one bud work 30 yrs in a similar garage, ran 20a ac on occasion and a 5 hp comp.

60a #2 mhf

 

[MagKarl]

sberry has a good point, I'd check into the new breaker you'll be adding to your house panel. See what size wire you can land in that new breaker, that may influence the wire size and thus feeder amperage. You also have the option to go copper but at a price premium.

I ran individual conductors for mine, 1/0 Al for about 200ft.

 

[shawn20630]

Thanks for that link to wire & cable, that 2/0-2/0-1-4 Aluminum Mobile Home Feeder Cable is much cheaper then at menards. I'm running a 200ft run at 100amps and this will be what i'm using.

 

[minytrker]

With 2/0-2/0-1-4 Aluminum Mobile Home Feeder will it change anything if I ran it from the pole (200amp) to the shop or will I need to drop it down to 100 amp at the pole before running to the shop. I originally was adding a 100 amp breaker to my 200 amp box on my pole and running 100 amp to the shop. My FIL is saying that's crazy to knock it down to 100 amp and to run it at the full 200amp to shop.

 

[wyliesdiesels]

With 2/0-2/0-1-4 Aluminum Mobile Home Feeder will it change anything if I ran it from the pole (200amp) to the shop or will I need to drop it down to 100 amp at the pole before running to the shop. I originally was adding a 100 amp breaker to my 200 amp box on my pole and running 100 amp to the shop. My FIL is saying that's crazy to knock it down to 100 amp and to run it at the full 200amp to shop.

2/0 AL isnt rated for 200a.

Max is 135a.

And depending on the distance, due to voltage drop useable amperage may be lower to keep voltage drop within 3% recommendations.

 

[ard]

With 2/0-2/0-1-4 Aluminum Mobile Home Feeder will it change anything if I ran it from the pole (200amp) to the shop or will I need to drop it down to 100 amp at the pole before running to the shop. I originally was adding a 100 amp breaker to my 200 amp box on my pole and running 100 amp to the shop. My FIL is saying that's crazy to knock it down to 100 amp and to run it at the full 200amp to shop.

Oh, didnt realize FIL was an electrician!



If you have a 200Amp service- a 200A main breakers feeding a panel, you can install a breaker in this and run whatever you want onwards. 200A, 125A, 100A.

The problem is that if you run 200A, you need a wire that will in fact handle 200A out at the distant end, 220feet away with only so much voltage drop.

You FILs advice may result in you spending $5-8 a foot for massive conductors and conduit, to give you 200Amps you will never use.

However, personally I like to allow for future options- so Id do 90-125 amp, you can figure the costs based in wire size and voltage drop and pick what feels best.

 

[minytrker]

That's kinda what I thought but wasn't 100% sure. The FIL and me usually have different ideas on the right way to do something, lol. The original plan was 100 amp. The original plan with 100 amp breaker and that wire for 220 ft showed a 3% drop if I remember correctly.

 

[minytrker]

Talked to FIL again and I misunderstood him a little. He was saying run the wire straight from pole into the shop and put a 100 amp breaker in my shop panel (in place of the 200 amp) vs putting the 100 amp breaker at the pole then running it into another 100 amp breaker at the shop. He was saying that would give me more power at the shop. I dont see how it would matter unless I was trying to use more than 100 amps at once. Having the 100 amp breaker at the pole seems like the correct way but I am not an electrician either.

 

[wyliesdiesels]

ok so you will be doing 100a breaker at the pole?

What kind of panel do u have at the pole?

Can u take a pic and post it here?

 

[minytrker]

My original plan was to add a 100 amp breaker at the pole. My FIL is saying run the power into the top of the box and just install a 100 amp breaker in the shop. I have a 200 amp breaker box on the pole with several slots open to add the 100 amp breaker. Only downside is its an old federal box (going off memory) so I might not be able to get a 100 amp breaker. I do have a brand new square d 200 amp for there and a 200 amp box in the shop but in order to replace it I would have to discount electricity to the house which makes me really nervous with a wife and 2 small kids. I'll try to get a picture of the box on the pole and post it.

 

[ard]

My original plan was to add a 100 amp breaker at the pole. My FIL is saying run the power into the top of the box and just install a 100 amp breaker in the shop. I have a 200 amp breaker box on the pole with several slots open to add the 100 amp breaker. Only downside is its an old federal box (going off memory) so I might not be able to get a 100 amp breaker. I do have a brand new square d 200 amp for there and a 200 amp box in the shop but in order to replace it I would have to discount electricity to the house which makes me really nervous with a wife and 2 small kids. I'll try to get a picture of the box on the pole and post it.

I know you know what you have, 'cause you can see it.... but refering to these items incompletely and disjointedly, mixing existing with new, what was planned at first, and now what is maybe planned next

Power doesn't run off poles. power runs from panels to panels, maybe from an overhead wire to a pole, down the pole into a panel. You dont put breakers on poles.

Just confusing....

The sole plan you present from FIL is:
"My FIL is saying run the power into the top of the box and just install a 100 amp breaker in the shop."
What does this mean????"run power into the top of the box. Which box????? "Install a 100Amp breaker in the shop". Do you (or he) mean 'a 100A disconnect as part of a 100A subpanel?'. It still needs a breaker wherever that line 'starts'.

How about a clear description of your overall electrical service- start at the wires on the power company pole not on your property....

 

[cobratom]

I recently ran into this with my build, obviously your wire would be a little different being in the US, but it will give you an idea.

I ran 100amp service 360' from Panel to Panel. Ran a 200A panel in the shop (as it is limited by the main panel breaker anyways), 3/0 aluminum direct burial (USEI-90) to a junction box in the house, where it was stepped down to 2 AWG aluminum, and into a 100A breaker.

The 3/0 was necessary in my case for voltage drop, however it also gives me the option to run a maximum 165A to the shop in the future, as it is rated for 165A. I would need to replace the 2 AWG from the junction box to panel if I would run greater than 100A.

The cost was actually not bad at all. Wire alone was just over $1000 CDN.

 

[wyliesdiesels]

I recently ran into this with my build, obviously your wire would be a little different being in the US, but it will give you an idea.

I ran 100amp service 360' from Panel to Panel. Ran a 200A panel in the shop (as it is limited by the main panel breaker anyways), 3/0 aluminum direct burial (USEI-90) to a junction box in the house, where it was stepped down to 4 AWG copper, and into a 100A breaker.

The 3/0 was necessary in my case for voltage drop, however it also gives me the option to run a maximum 165A to the shop in the future, as it is rated for 165A. I would need to replace the 4 AWG from the junction box to panel if I would run greater than 100A.

The cost was actually not bad at all. Wire alone was just over $1000 CDN.

Umm i dont know about canada but in the US #4 cu isnt large enough for 100a.

 

[Bert_]

My original plan was to add a 100 amp breaker at the pole. My FIL is saying run the power into the top of the box and just install a 100 amp breaker in the shop. I have a 200 amp breaker box on the pole with several slots open to add the 100 amp breaker. Only downside is its an old federal box (going off memory) so I might not be able to get a 100 amp breaker. I do have a brand new square d 200 amp for there and a 200 amp box in the shop but in order to replace it I would have to discount electricity to the house which makes me really nervous with a wife and 2 small kids. I'll try to get a picture of the box on the pole and post it.

There is nothing wrong with connecting your smaller wire to a 200 breaker as long as it terminates to a breaker in the shop that is correct for the size wire you chose. This is called a tap and is perfectly acceptable as long and no more than 25' of the wire is to be run inside the building. The outside portion can be as long as you need.

 

[wyliesdiesels]

Yes it is. Both NEC and CSA (Canada) allow for 4 AWG to run 100A as a service or feeder conductor. It is rated for 95A in any other deployment.

That's for DWELLING units. Notice the first 3 words? A garage shop etc is NOT a dwelling unit.

And notice that code is for 3-wire service entrances. A garage shop etc needs 4-wire feeder if fed off an existing service.

so no #4 cu is not large enough for a 100a 4-wire feeder to a shop, garage etc.

And 95a ampacity for #4 is for derating purposes only and #4 cannot be breakered at that rating.

 

[cobratom]

That's for DWELLING units. Notice the first 3 words? A garage shop etc is NOT a dwelling unit.

And notice that code is for 3-wire service entrances. A garage shop etc needs 4-wire feeder if fed off an existing service.

so no #4 cu is not large enough for a 100a 4-wire feeder to a shop, garage etc.

And 95a ampacity for #4 is for derating purposes only and #4 cannot be breakered at that rating.

Why exactly would you need to run a 4 wire feeder to a shop or garage? That may be the difference in code between here and US. We run 3 wire to a detached building, and use a grounding plate at the building for ground.

(Also, I did make a mistake in wire, they were going to use 4AWG Copper, but decided to use 2AWG Aluminum instead, but they are within 5amps rating of one another). Please remember this was fully permitted job, so all inspections took place.

 

[wyliesdiesels]

Why exactly would you need to run a 4 wire feeder to a shop or garage? That may be the difference in code between here and US. We run 3 wire to a detached building, and use a grounding plate at the building for ground.

(Also, I did make a mistake in wire, they were going to use 4AWG Copper, but decided to use 2AWG Aluminum instead, but they are within 5amps rating of one another). Please remember this was fully permitted job, so all inspections took place.

US NEC code now requires 4-wire feeders to detached structures. Pre-2008 NEC code allowed 3-wire feeders.

The change was attributed to the potential for objectionable neutral currents to flow on unintended metallic pathways such as metal structures conduits etc because of the neutral to ground bond in the subpanel at the detached structure. This can and has happened when the feeder neutral developed a bad or high resistance connection on either end.

So code changed to requiring 4-wire feeders- 2 hots neutral and EGC(equipment grounding conductor)/ground.

BTW grounding electrodes and EGCs are 2 different animals in case u were associating the 2.

And #2 AL is good for 90a to a detached structure, NOT 100a.

 

[cobratom]

US NEC code now requires 4-wire feeders to detached structures. Pre-2008 NEC code allowed 3-wire feeders.

The change was attributed to the potential for objectionable neutral currents to flow on unintended metallic pathways such as metal structures conduits etc because of the neutral to ground bond in the subpanel at the detached structure. This can and has happened when the feeder neutral developed a bad or high resistance connection on either end.

So code changed to requiring 4-wire feeders- 2 hots neutral and EGC(equipment grounding conductor)/ground.

BTW grounding electrodes and EGCs are 2 different animals in case u were associating the 2.

And #2 AL is good for 90a to a detached structure, NOT 100a.

Again, you are quoting NEC, so the correct statement would be "In the USA, #2 AL is only good for 90A."

However, I am in Canada, where the ESA (Electrical Safety Authority) Rules the land, and around here ESA has A 100A rating on ACWU90 2AWG wire..

Also, our code also permits 3 (full size, no undersized neutral) wire runs to detached buildings, and my ground is a grounding plate and it is not bonded to the neutral at the subpanel. This install took place in summer 2016, as is definitely up to code.

I guess there are some differences in how our electrical authorities see things.

 

[wyliesdiesels]

Again, you are quoting NEC, so the correct statement would be "In the USA, #2 AL is only good for 90A."

However, I am in Canada, where the ESA (Electrical Safety Authority) Rules the land, and around here ESA has A 100A rating on ACWU90 2AWG wire..

Also, our code also permits 3 (full size, no undersized neutral) wire runs to detached buildings, and my ground is a grounding plate and it is not bonded to the neutral at the subpanel. This install took place in summer 2016, as is definitely up to code.

I guess there are some differences in how our electrical authorities see things.

Yes and the OP is in the US so there is no point in quoting canadian code on this thread.

I dont know canadian code so i dont give code on threads where the OP is in canada.

 

[Bib Overalls]

Went to the link that Pattenp provided and found this stuff:

https://www.wireandcableyourway.com/Underground-Secondary-Distribution-Cable/

Seems to be interchangeable with MHF and not as pricey. Am I missing something here?

My shop is currently serviced with 60 amps. Never had a light flicker when a load came on line but I am marginal when the heat pump goes into back up heat mode. Planning on upgrading the system at some point but I'm not in a hurry.

 

[brewchief]

Went to the link that Pattenp provided and found this stuff:

https://www.wireandcableyourway.com/Underground-Secondary-Distribution-Cable/

Seems to be interchangeable with MHF and not as pricey. Am I missing something here?

The insulation on URD cable isn't rated to be used indoors, therefore you would need to use a different wire inside with the proper rating and splice them outside.