Electrical run between house and garage.

[weatherby460]

My house has 200 Amp service. I will need to run wire about 100 feet to my new garage. I assume 100 Amp 220 is the standard. What would this cost to have an electrician do the work? What would it cost just for the wire, and what size is needed?

Thanks

Correction its 100 feet I need to go from my existing panel to the new garage.

 

[kd3pc]

there is no "standard" You need to see what the capacity of your house service is, and if you can tap that for another 100 amp service. 100 yards will put you in the "voltage drop" needs to be considered in the design.

The other questions are answered by, it depends. Perhaps some one way more local to you can let you know what to expect. Having an electrician do it, will double or triple the cost of you or DIY family doing it.

Have you spoken with the local power company, they may have some useful information for you, that is pertinent to your situation.

 

[jvitez]

Heaping piles of spam scented quadruped excrement reported!

 

[weatherby460]

How did that happen???????

 

[CNGsaves]

Likely the most affordable will be MHF (mobile home feeder) aluminum 2-2-2-4 which is around $1.50/ft at most big box stores (Home Depot/Lowes). Bury the 100 ft run to garage inside 2" Sch 40 conduit in trench deep enough for your AHJ (authority having jurisdiction) - - - likely maybe 36" deep or deeper. Once above ground, the 2" conduit needs to be Sch 80 and keep the MHF wire in conduit all the way to subpanel. Good idea to backfill about a foot, then install another plastic conduit 1" and run all your low-voltage stuff like CATV, internet, phone, security, etc. (ie RG6 and couple CAT5e/6 along with pull string for future upgrades)

The MHF Al 2-2-2-4 electric wire would be good for 90A breaker in main panel, and just use 100A subpanel in the garage.

 

[weatherby460]

any idea how much this will run?

 

[86turbodsl]

I put in a direct burial 100 yard run to my pole barn, 200A though. Seems like my wire was about $500. I paid the power company subcontractor 200 to do the trench since he was right there at the same time. Power usually only has to be down about 18". 36" is overkill in my opinion. I bet you have near 500 in it by the time you buy conduit, glue, rent trencher, and all your fittings, etc.

 

[plow]

100 feet, or 100 yards?

 

[Revin]

I did same as you
I will be running #2 thhn.
one hot, one netural then a #6 for the ground

 

[weatherby460]

300 feet

 

[ddawg16]

100Amp? That is a lot. I've got 50A to my garage and I'm no where close to using all of it. Worst case....compressor (240Vac), lights and one power tool.

Personally, I would not do direct bury cable...but rather conduit.....

You will have to dig a trench....so might as well do conduit so you can pull more wire later....and while you're at it, do a second conduit for data.

PVC conduit is cheap

As for cost....material cost should be less than $700...your labor would be free...and maybe $100 for the trencher.

For me, the big cost would be the beer factor....a couple of friends over to help? Yea, lots of beer.

 

[wyliesdiesels]

I did same as you
I will be running #2 thhn.
one hot, one netural then a #6 for the ground

That will only do 120v. U need another hot leg for 120v/240v...

300 feet

Is it 100' or 300'? U keep going back and forth. The distance WILL change the wire size requirement!

 

[weatherby460]

100 yards or 300 feet

 

[wyliesdiesels]

For 100a feed 300' i recommend 3/0 AL....theres several ways to go about this! Depends on budget and skill!

 

[weatherby460]

It is actually only 100 feet I need to go. Got a quote for 2 gauge wire in conduit for $1500....that seems like a good fair deal to me.

 

[theoldwizard1]

100Amp? That is a lot. I've got 50A to my garage and I'm no where close to using all of it. Worst case....compressor (240Vac), lights and one power tool.

50-60A is more than enough for a 1 man operation. The only way I can see you exceeding that is if you are running a plasma cutter and a CNC with your A/C on !

 

[Justanoldguy]

My house has 200 Amp service. I will need to run wire about 100 feet to my new garage. I assume 100 Amp 220 is the standard. What would this cost to have an electrician do the work? What would it cost just for the wire, and what size is needed?

Thanks

Correction its 100 feet I need to go from my existing panel to the new garage.

300 feet

100 yards or 300 feet

It is actually only 100 feet I need to go. Got a quote for 2 gauge wire in conduit for $1500....that seems like a good fair deal to me.

Glad you got that sorted. or not?

 

[86turbodsl]

Personally, I would not do direct bury cable...but rather conduit.....

Keep in mind, if you are using wire in conduit, you have to use bigger wire, because the earth isn't in direct contact, so the wire ampacity will go down because it's just conductor in free air rather than cooled by earth.

there's charts of what wire to use in what circumstances.

 

[wyliesdiesels]

It is actually only 100 feet I need to go. Got a quote for 2 gauge wire in conduit for $1500....that seems like a good fair deal to me.

Seriously? Whats with the back and forth on the length?

Glad you got that sorted. or not?

It'll change again. U watch!

Keep in mind, if you are using wire in conduit, you have to use bigger wire, because the earth isn't in direct contact, so the wire ampacity will go down because it's just conductor in free air rather than cooled by earth.

there's charts of what wire to use in what circumstances.

What on earth are u talking about? Do u have a code reference for that? Thats all wrong!

Wire used in conduit isnt the free air type. The space in conduit isnt considered free air. Free air wire and ampacities is for wire hanging in the air such as wire used for overhead service drops. And Free air wire actually has a higher ampacity.

And the cooling of the earth plays no part on wire ampacity either!

The ampacity of wire used underground doesnt change if its used in conduit. For example, #2 AL MHF has the same ampacity (90a) whether its direct buried or used in conduit.

Where did u get any of this information?

 

[Rod N]

Whatever you do make sure the line coming from the house is above grade.
Then you will have less risk of water leaking in every spring.
Ask me how I know.

 

[volleyball]

I think it would be foolhardy to run less than 90A in a new installation. Maybe you won't ever use more than 30A but then again in a few years you get an electric car and want to take advantage of a faster charge current. Maybe you take up powder coating, or welding.

If you are only running 20 feet and are doing it yourself, go whatever you need today and next year. You don't want to pay someone to redo a 100 feet or yards run.

 

[86turbodsl]

What on earth are u talking about? Do u have a code reference for that? Thats all wrong!


Where did u get any of this information?

I read it a long time ago. To be honest, it was so long ago i don't remember where, may have been a journal or something like that. I'm old enough it could even have been pre-internet.

If you think about it though, conductors in contact with earth have a cooling medium same as a geothermal pipe in the ground conducts heat.

conductors in conduit can heat the air in the conduit. 2008 NEC even allows for conductor derating for conduit, although it's for sun loading.

I'm not married to it though, if i'm full of it, i'll stand corrected and we'll move on.

 

[wyliesdiesels]

I read it a long time ago. To be honest, it was so long ago i don't remember where, may have been a journal or something like that. I'm old enough it could even have been pre-internet.

If you think about it though, conductors in contact with earth have a cooling medium same as a geothermal pipe in the ground conducts heat.

conductors in conduit can heat the air in the conduit. 2008 NEC even allows for conductor derating for conduit, although it's for sun loading.

I'm not married to it though, if i'm full of it, i'll stand corrected and we'll move on.

That may be true that the earth can cool something but thats not used or accounted for. U were suggesting that when a conductor is direct buried it has a higher ampacity than when its in conduit because of the cooling of the earth. But thats not the case.

Yes u do have to derate conductors if more than 3 CCCs are used in a raceway due to heating...

 

[86turbodsl]

Thanks Wylie. I stand corrected.