Cost estimates for electrical service

[varunner]

Looking for opinions and price info concerning which way to go on this. The detached garage is 32 x 44 and will have 200 amp service.

Option 1: Have the power company install new service to the garage. It's 300 ft. from the power pole/transformer to the new garage, the service would be underground. With pricing from the power company, providing new service is approx. $500. Of course there will be a monthly charge, something like $30.

Option 2: Upgrade the service to the house from 200 to 400 amps and feed the garage 200 amps with cable underground. So basically I need help in estimating the costs for this. It is 175 ft. from the meter base on the house to the new garage. Upgrading the meter base from 200 to 400amps isn't too hard. The meter base itself is free from the utility and I have friend who can help with the changeover. What will cost is renting a trencher, the cost of the UF cable(not sure of what gauge it should be), and adding a seperate grounding cable. The trencher is probably around $200, unfortunately this trench will cross all of my exsisting utilites, so I'm going to have to hand dig 20 -30 ft. of the trench. Any help with specs of the exact type of the cables and their costs is much appreciated.

Brian

 

[tdkkart]

First of all, what makes you really think you need 200 amps to the garage?? How many people are you employing in your workshop??

I see alot of people here taliing about having 200amp services to their garage/shop, but unless you've got a really heavy duty welder, AND an electric water heater and central air in there, most can get by on 100 amps or less.

My garage contains a milling machine, lathe, 2 stage compressor, 110v welder, 220v TIG welder, alot of lighting and several other items, works just fine on a subpanel driven from a 60amp breaker in the house.

Big electricity is expensive, figure out what you need before spensing more money than you have to.

 

[varunner]

Fair question. Do I need 200 amps right now? probably not. would it be a good idea to plan ahead and have extra capacity? I'd say so. Starting off, I'll have the same compressor as you, 2 welders, milling machine, 2 PTHP units, car lift, and the usual lights, receptacles. Doing a load calculation before doing any electrical work is a must and has to be done before the local uility will start any work. For now I simply need to determain if I'm attaching a meter base to the exterior of the garage or not so that I can start the siding.

 

[tdkkart]

Fair answer, and I'm not one to under-do anything either, just thought I'd check.....
It wasn't so long ago that houses were done with only 100amp services and did just fine, the only ones that had 200amps were the ones with electric heat.
For that matter my dad only has a 400amp service for his whole farm, including a fair size corn-drying setup. Which BTW, they required a pole-top disconnect on his 400 amp service.


But, double check everything with the power company, I was reviewing our companies guidelines the other nite and it appears that they don't even allow a 2nd meter in a residential application?? Who knows why, but that's the way I read it.

 

[SteveU]

Figure worst case scenario, you have a couple buddies over & you are running the 3 highest draw machines you have & the air compressor kicks on. My compressor draws 45 amps starting vs 19.5 running, tablesaw draws 37 amps starting, lights are 9 amps so it adds up quick. One thing to look at is where I am I can have as many meters as I want but will pay commercial rates on all but 1 so by the time you add up the meter charge and double electric rate over time you can pay for a lot of wire.

 

[varunner]

Our power co. will certainly provide a new meter and and hopefully charge residential rates, but I'm definately going to double check that.

I found some NEC load calculation software that I will use. I would think that it takes in account the start-up loads. In any account the cable that I'm considering burying will be sized for a 240v/200amp service. This is what I need to estimate the cost of. If the load calculations say that 100 or 150amp service is all that I need, I would want to be able to upgrade the service in the future so I want the cable to be able to handle it. I know this cable isn't cheap, but I don't want to do this twice.

thanks for the input.

 

[Lyaec350]

First of all, what makes you really think you need 200 amps to the garage?? How many people are you employing in your workshop??

I see alot of people here taliing about having 200amp services to their garage/shop, but unless you've got a really heavy duty welder, AND an electric water heater and central air in there, most can get by on 100 amps or less.

My garage contains a milling machine, lathe, 2 stage compressor, 110v welder, 220v TIG welder, alot of lighting and several other items, works just fine on a subpanel driven from a 60amp breaker in the house.

Big electricity is expensive, figure out what you need before spensing more money than you have to.

How is this possible? My welder needs a 50amp breaker on its own... My garage has a 200amp panel and i wish it were more. Think about it this way, could you have the lights on (15 amps), be playing some tunes and running a fan or 2 (10 amps), welding (50 amps) and running a 220V compressor to fill the tank back up (30amps) at the same time with a 60amp panel? No way.

We have 2 200amp panels in the house and a 200 amp panel for the garage. Would definitely go w/ 200 amp panel out there.

No reason to undersize on something like electrical service...

 

[W-Cummins]

How is this possible? My welder needs a 50amp breaker on its own... My garage has a 200amp panel and i wish it were more. Think about it this way, could you have the lights on (15 amps), be playing some tunes and running a fan or 2 (10 amps), welding (50 amps) and running a 220V compressor to fill the tank back up (30amps) at the same time with a 60amp panel? No way.

We have 2 200amp panels in the house and a 200 amp panel for the garage. Would definitely go w/ 200 amp panel out there.

No reason to undersize on something like electrical service...

Why, do you trip of the breaker on your current 200 amp service??

Has your welder ever pulled 50 amps?? Do have a 7.5 hp compressor that needs 30 amps to run?
If your pulling 15 amps on your lighting you must have a large place or _LOTS_ of lights.
There is no reason (with the cost of materials today) to totally over size it either!

William....

 

[varunner]

Ok. So I now have to ask the experts. How do you properly size your breaker panel?

Here is the link to an online calculator: http://www.zenfixit.com/load_calculations.shtml

It looks like it's created for a single family home, although it may be able to be used for a garage or similar structure.

 

[Lyaec350]

Why, do you trip of the breaker on your current 200 amp service??

Has your welder ever pulled 50 amps?? Do have a 7.5 hp compressor that needs 30 amps to run?
If your pulling 15 amps on your lighting you must have a large place or _LOTS_ of lights.
There is no reason (with the cost of materials today) to totally over size it either!

William....

No, I don't trip the 200amp breaker, thats the whole point, if I were tripping it my service would be too small

I just calculated my power draw for lights in a 700 sq ft shop: 1800 watts of fluoro lights, and 600 watts of halogens = 2400 watts @ 120V = 20amps. Thats running not starting. I don't have a 7.5 HP compressor yet, but it is in the plans. I've never attached an amp meter to the welder, but the book says to put it on a 50amp breaker so running all out it must pull ~40 amps when it's running full out.

Also, consider the possibilities of central air, if you get a central air unit you'll want at least another 40amps available. My point was simply that it adds up quick, if you're going to the trouble of digging a trench and running a bunch of wire why not do it right the first time and never worry that you might exceed the available amps. I'm not saying you need commercial 3-phase or anything, just that it is not a bad idea to go a bit bigger than you calculate your "need" to be, as you will always find new toys

 

[jay50]

200amps is plenty. Save yourself some $s for the shop tools instead of lining the pockets of the power company.

 

[chevytruck]

I would go as big as you want, But doubt you would ever need more than 100 amp service. You plan on running all your lights all the time or switched seperatley? I have three rows all switched seperate. Dont need them all on when only working in one area of the garage.

 

[varunner]

Finally have sorted out both options, splitting the service at the house or having the utility provide a new service to the garage. Getting a new service to the garage, is about $200 cheaper than upgrading the service at the house to 400amps and splitting off 200amps to the garage. The local utility is running underground 200amp service to the garage for $441, complete. That's an almost 200' run from the pole to the garage, sounds like a good deal to me......and all I have to do is watch them

 

[chevytruck]

sounds like a good deal to me also, I think your making the better choice doing it that way IMHO

 

[HacksawsGarage]

441 bucks? you cant rent a Vemeer , a trailer and truck, plus an operator for that around here. i bet the permit alone would cost that here in Ct.

 

[Ezzie]

Option 1: Have the power company install new service to the garage. It's 300 ft. from the power pole/transformer to the new garage, the service would be underground. With pricing from the power company, providing new service is approx. $500. Of course there will be a monthly charge, something like $30.
Brian

WOW!! Something strange here. I am about the same distance (actually 325'). I was told by my utility co. they won't do a 200A either overhead or underground at that distance - 100A yes, but not 200A (about 175' max.) due to voltage drop issues. They want me to pay to bring the medium voltage in part way to either a pole mounted transformer or pad mount (in the case of underground).

 

[varunner]

I believe the location and size of the nearest transformer is a major factor in determining what kind of service that can be supplied to a customer. It's all about the expected return on their investment is what drives what they'll offer to you.

 

[ron in sc]

It's all about the expected return on their investment is what drives what they'll offer to you.

It's hard to figure what they base the amount they charge to do this kind of work or even if they'll do it.

I upgraded to 400 amps to house and then split it between house and garage. They dug a 42" tench from my house to the power pedestal which is about 60' away. Then ran new wire in new 3" conduit. As I recall it cost about $500. I thought it was going to cost much more.

 

[varunner]

I agree. Lots of times what is cheaper in one part of the country is higher in the other part. No matter where you live, it pays to price it out in your own area.