Power...how much do I really need

[3rdgendslmech]

Hey guys so hopefully shortly after holidays I'm going to be starting the next phase of my pole barn build (24x32x10). Hopefully I'll have some electricity out there. For right now I've just got 3 8ft shop lights that I wired up to run off of an extension cord to the house.
So what I'm working with is a 200 amp Bryant main panel (see photo). I've got 3 spots I could throw in a breaker to supply the sub panel to the barn. It's about a 120' run from panel to panel.
I was going to go with 100 amp service but I might downgrade a slightly. As far as what type of equipment I'll be running....Either a lincoln Pro Mig 180 or a Hobart 210MVP mig welder. 60 gallon compressor 230V 15amp (husky from home depot) or comparable. And maybe some form of heater....not too sure yet on what type, honestly I'm just happy right now to be able to be in a building with lights and be able to work out of the weather! As far as lights go, I might add 1 more 8ft light over my toolbox and work bench, and 2 floodlight fixtures over the sliding door, and personel door. I'm planning on putting 4 outlets with a double in the middle of each and an outlet outside on the front wall. I had gotten 2 opinions from electricians where I work, the one guy basically said go big or go home and run 100amp service. The older more level headed and experienced guy said I could probably get away with running 60 or 75 amp service.
So based off of what I just said, does all of that sound reasonable for 60 amp service? 95 percent of the time it will be just me in the shop doing auto repair mostly.

 

[firebirdparts]

60 amps is plenty for working in the shop. "Some kind of heater" needs to be selected before you go any further. Baseboard heaters use a lot of power. In Maryland you might be tempted to put in a heat pump (I did).

 

[tarmy]

More than you think...

I have a dedicated 200A panel...and it is full. Kept adding 220 equipment, adding lights, adding exterior features...overhead winch, charging station...

Think of the circuit setup...not just the load. I could never use the 200 myself...but the way I wanted to pwer things, set up circuits etc...I filled it up...

 

[jvitez]

2 points have been brought up:

1. Total electrical load.
2. Panel space.

For total electrical load you need to do some advanced planning. One man shop or more? Think of every possible thing you would want running at the same time, like the welder just when the compressor kicks in, all the lights, and as mentioned what specific wattage of electric heater. Add this all up, divide by 240, and that's the total amount of amperage you need to supply, and actually a bit more for future proofing.

For panel spacing, figure out how many breaker spaces the electrical equipment you decided on in Number 1 will need. That's the size panel you need.

So lets say you come up with 10,000 watts as total load ( eg. 5000W heater, 2500W welder, 1500W compressor, 1000 watts lighting), that's 41.7 amps, so run a 60 amp feeder cable. But what if your circuits and equipment use up 20 breaker spaces? Then buy a 100 amp 30 space panel. The 100 amp main breaker acts as a shut off because the whole panel is being fed by a cable protected by a 60 amp breaker from your main panel.

 

[BillK]

I have a 100 amp sub in my 24 x 24 detached. The difference in cost between 60 and 100 is not that much and it would give you the cushion in case you decide to go with electric heat or ac in the future.

My vote is for 100 amp.

 

[gungatim]

I say less than you think. I have a 60 amp panel run 130' from the house with a 40 amp breaker in it just to be safe. with mill, mig, tig, compressor, arc welder fridge, 4 amps, 2 TV's, drill press, mill, lathe, lights, and a hot tub, I have only blown the main once when the compressor kicked on with the hot tub running while the fridge kicked on. that was my fault for not turning off the compressor since it is on the same 220v circuit as the hot tub...which should be dedicated anyway but It was a temporary thing.

in a one man shop it is difficult to run enough machines to pull as much power as people think...60 amps is plenty.

 

[PCustoms]

I have a 100 amp sub in my 24 x 24 detached. The difference in cost between 60 and 100 is not that much and it would give you the cushion in case you decide to go with electric heat or ac in the future.

My vote is for 100 amp.

The panel in your garage doesn't determine your availible power.

The breaker in the main panel and the feeder to the sub determines that.

 

[wssix99]

2 electric cars in there and - that will put you over 100A.

How long are you going to live with your barn?

If you are going to be around for 10-20 years and will store two active driving cars, then you'll probably want the juice some day to handle the big electrical things everyone is moving to.

 

[bczygan]

60A and 90A are sweet spots for cost of wire feed to panel.

 

[Notgrownup]

I have a 100 amp sub for my 24x24, plenty for me. 75’ cable run from the main.

 

[laser3kw]

The difference in cost between 60 and 100 is not that much

I fed my sub panel from the house. The house panel is 100amp, so by code (per the electrician) I could only feed the sub panel with 60 amp breaker max. The feed going to the garage was sized for 100 amp as well as the sub panel main. It was hinted that if I ran into a problem with breaker trips in the house, I could swap the 60 amp breaker with a 90 (wink wink).
To date, 5 years later, I have not tripped the 60 amp. I have a wide variety of 240v toys, I just don't use them all at once.

 

[mrramsey]

Depending on the location of your barn and the incoming power pole don't rule out the possibility of adding a second meter.

 

[2Big2Ride]

In our 60'x30' we have a 200A service, but we don't need that much power. We do need a lot of spaces in the panel. Not down playing the need to evaluate power needs, but as important is the planning piece for spaces in the panel to accomidate the needed circuits.

Think we have about 7 potential empty spaces at the moment in a 30/40 circuit main panel and 8 circuit subpanel. ...using tandem breakers get you from 30 circuits to 40. Three of the empty spaces are planed for a 240V future circuit or converting a current 120V to 240V. Without going to look, think we currently have eleven 240V separate circuits that eat up a lot of spaces.

 

[theoldwizard1]

60 amps is plenty for working in the shop. "Some kind of heater" needs to be selected before you go any further. Baseboard heaters use a lot of power. In Maryland you might be tempted to put in a heat pump (I did).

Concur with both !

60A is a good "rule of thumb" for a one man shop, unless you are planning on having a welding party with 2 or 3 guys welding at the same time. Lower breaker means you can save money on wiring.

I know a heat pump will cost a lot more than any other solution, but the cost to run it is MUCH lower than many energy sources and you get A/C !

 

[ez-duzit]

...run 100amp service...

This guy was the more level headed of the two. Don't cheap out. I put 100-amp service in my own 1-man shop.

 

[wyliesdiesels]

I fed my sub panel from the house. The house panel is 100amp, so by code (per the electrician) I could only feed the sub panel with 60 amp breaker max. The feed going to the garage was sized for 100 amp as well as the sub panel main. It was hinted that if I ran into a problem with breaker trips in the house, I could swap the 60 amp breaker with a 90 (wink wink).
To date, 5 years later, I have not tripped the 60 amp. I have a wide variety of 240v toys, I just don't use them all at once.

Not sure where your electrician came up with that but its BS.

There is no code that limits a feeder breaker to less than the main panel rating or main service size.

You couldve fed your garage with 100a.

Its all about diversity of connected loads.

 

[zmaxmotorsports]

Not sure where your electrician came up with that but its BS.

There is no code that limits a feeder breaker to less than the main panel rating.

You couldve fed your garage with 100a.

 

[stevengarage]

I have 60 amp in my 24x26 garage. I got opinions from several electricians and they all said 60 would be sufficient in a home garage.

 

[NUTTSGT]

Depending on the location of your barn and the incoming power pole don't rule out the possibility of adding a second meter.

Always a good suggestion or a thought to consider. I have a 200A service in the garage and a 200A service in the house. Two electric bills, gives me an option if we ever sell the place.

 

[ez-duzit]

I have 60 amp in my 24x26 garage. I got opinions from several electricians and they all said 60 would be sufficient in a home garage.

For a home garage to store your cars, yes--not for a shop.

 

[finn]

The electrician who roughed out my garage recommended 60 amp service. I went with 100 amp. It cost more, maybe a couple hundred dollars, I forget, but many years later it’s a non issue.

I later bought a shop with 200 amp service.

I’m happy.

 

[James-W]

I have a separate 200 amp service in my garage. It more than meets my current needs, but who knows what my electrical needs will be tomorrow? I figured by having more power installed now I am prepared for what the future brings. I have always found it better to be proactive rather than reactive.

 

[Matt Matt]

If you really want to plan for the future, you need about 200 A fed to a garage/shop. Most household services cannot provide this (and neither the supply) , but this is what really should be there. If electric cars are going to play a part of our future, we will need to supply at least 90 A to a car charging station. Right now 40/50/60 A feed is sufficient to put a Tesla back on the road in six hours.

Ideally, if an electric car is not in your near future, 60–100 A is perfect for most shops. Air compressor, lighting, Heating and air conditioning(maybe fridge, washer, dryer)are your first out of control consumables. But, if you weld, you have to add an extra 30-60A just for the welder.

With all your major uncontrolled consumables online, you want to be at 80% , Now you want to add on any additional power consumption’s and still be at 80% of the feed breakers/Circuit allowance for safe keeping.

If I’m welding, I can pull 40 A on my Tig, my lighting 6A and if my air compressor kicks in another 22 A if my AC kicks in maybe 6 A more.... Motor start load can easily be 4 to 6 times inrush depending on load.... My dust collector in my other shop pulls almost 110 A in start up, but is only one of 30 A feed circuit.

 

[prosparky]

Consider the price of the wire or cable as well. I just installed a 100 amp panel in my 24 x 24 garage. 3c # 6 cable (copper) was $2.79 / foot, and 2/2/2/4 SER cable (aluminum) was $1.69 / foot. This made up the cost difference between a 60 and a 100 amp 2 pole breaker.


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[yeldogt]

Up-charge cost for 100 amp is small -- no point in going with less.

 

[pattenp]

Consider the price of the wire or cable as well. I just installed a 100 amp panel in my 24 x 24 garage. 3c # 6 cable (copper) was $2.79 / foot, and 2/2/2/4 SER cable (aluminum) was $1.69 / foot. This made up the cost difference between a 60 and a 100 amp 2 pole breaker.


Sent from my iPhone using Tapatalk

Hope you didn't use 2-2-2-4 SER with a 100A breaker because 90A is max breaker size for #2 AL.

 

[3rdgendslmech]

Hey guys sorry for the delayed response. So I think I'm going to go with 100 amp service. Like it was said the cost would only a couple hundred more to do. When I built it I had joking said to my wife I should have made it bigger so she could have a gym/craft area. So in another 5 years or so I'll most likely be expanding.
As far as heat goes....not too sure yet. There's no insulation up yet. Would probably frame out the walls with 2x6s. How are the ceiling hung propane heaters?
So now the real question based on the panel that I posted, would most electricians be able to snap in a breaker and run the wires? I'm just worried that once I start getting estimates they're all going to want to upgrade my main panel because it's 30 year old technology.?
Haven't completely put off doing the install myself just having trouble finding time to do the work is my hold up.

 

[wssix99]

Plus, keep in mind the awesome Tesla Coil you'll be building when you get to retirement.

There's no better way to keep kids off your lawn.

 

[Falcon67]

So based off of what I just said, does all of that sound reasonable for 60 amp service? 95 percent of the time it will be just me in the shop doing auto repair mostly.

My shop has - 60 gallon 240V air, two air conditioners, 240V 5kW heater, mill, two lathes - one fractional, the other 2 HP 240V, wood and metal band saws, drill press, lift with 240V pump, 240V well pump (3/4 or 1HP not sure), lots of lights, beer fridge, etc, etc.

70A on the feed, never tripped. It's fed with 2-2-2-4 which is good for 90A but HD had a 70A sitting on the shelf when I bought my feed equipment and that's what I used.

Had same stuff at the old shop, less one AC unit and one lathe and ran that building on 60A.

The 130' MHF, a 20A panel, feed breaker, misc panel breakers, ground bars, etc - whole pile was under $250 out the door.

 

[theoldwizard1]

Hey guys sorry for the delayed response. So I think I'm going to go with 100 amp service. Like it was said the cost would only a couple hundred more to do.

Follow Falcon67's lead !

My shop has - 60 gallon 240V air, two air conditioners, 240V 5kW heater, mill, two lathes - one fractional, the other 2 HP 240V, wood and metal band saws, drill press, lift with 240V pump, 240V well pump (3/4 or 1HP not sure), lots of lights, beer fridge, etc, etc.

70A on the feed, never tripped. It's fed with 2-2-2-4 MHF which is good for 90A but HD had a 70A sitting on the shelf when I bought my feed equipment and that's what I used.

As far as heat goes....not too sure yet. There's no insulation up yet. Would probably frame out the walls with 2x6s. How are the ceiling hung propane heaters?

They work fine. The only issue is you get a blast of hot air when they come on so watch where you aim it. As I mentioned before, they are NOT the lowest cost of operation.

Remember, most of the heat loss is up through the ceiling so the more insulation you can put up there the better.

So now the real question based on the panel that I posted, would most electricians be able to snap in a breaker and run the wires?

Of course they will try to up sell you ! Breakers are available even though Bryant was bought out long ago.

 

[sberry]

Believe it or not it's not hard to stop welding if the comp happens to come on which it shouldn't if not using air at the same time. It's not a short run, not a super long one but number 2 wire is the cheapest and good for 90 but I have done a dozen using a 60 and never had a trip call including a couple busy places with 5 HP comps on them.
Wired one in yesterday.

 

[2level]

Good choice, IMO. A couple hundred bucks for the option to use electric heat, charge a vehicle, future proof for expansion or another owner, ect. How much is electricity per Kwh vs. propane cost per Btu in your area currently?

 

[theoldwizard1]

Good choice, IMO. A couple hundred bucks for the option to use electric heat, ...

Electric heat is the cheapest to install and the MOST expensive to operate !

 

[wyliesdiesels]

....So now the real question based on the panel that I posted, would most electricians be able to snap in a breaker and run the wires? I'm just worried that once I start getting estimates they're all going to want to upgrade my main panel because it's 30 year old technology.?
Haven't completely put off doing the install myself just having trouble finding time to do the work is my hold up.

Of course they will try to up sell you ! Breakers are available even though Bryant was bought out long ago.

The Eaton BR line is the successor to Bryant panels and breakers.

Entry level cheap breakers.

Some electricians may try and sell you on an upgraded panel such as an Eaton CH with copper bus. But if your BR is in decent shape, why upgrade? Breakers are readily available.

 

[AP514]

Do not sell yourself short/Cheap out...Go with the 100 Amp Panel...You will be happy you went with the 100 Amp in the long run

 

[3rdgendslmech]

We don't have natural gas running to our neighborhood. I was thinking along the lines of a 200 gallon tank. So the house is already on a heat pump system, which isn't bad IMO but ***** when temps in MD get below 30.

 

[OccupantRJ]

I have 60 amps on my shop and I am upgrading to 100 amps at this time. Just using the blast cabinet I am using around 30 amps with the compressor, baghouse blower and lighting. There is also a 2-1/2 ton heat pump with heat strips. See where this is going? You run out of amps fast if you have equipment of any size.

 

[lakelandcat]

Hey guys sorry for the delayed response. So I think I'm going to go with 100 amp service. Like it was said the cost would only a couple hundred more to do. When I built it I had joking said to my wife I should have made it bigger so she could have a gym/craft area. So in another 5 years or so I'll most likely be expanding.
As far as heat goes....not too sure yet. There's no insulation up yet. Would probably frame out the walls with 2x6s. How are the ceiling hung propane heaters?
So now the real question based on the panel that I posted, would most electricians be able to snap in a breaker and run the wires? I'm just worried that once I start getting estimates they're all going to want to upgrade my main panel because it's 30 year old technology.?
Haven't completely put off doing the install myself just having trouble finding time to do the work is my hold up.

Ever said to yourself "I wish I would have!" Its better to have it and not need it, than to need it and not have it.

 

[2level]

Electric heat is the cheapest to install and the MOST expensive to operate !

Sometimes it's more cost effective to use electric. Depends on usage / amount, up front costs, local energy costs, heat pump vs. electric resistance heat, ect. Some propane systems are fed from portable tanks. I noticed a sign advertising $2.69/gallon for propane today. I pay 7 cents/kWh plus taxes for electric, and use Packaged terminal heat pumps in the shop.

OP - How often do you think you will want to have the heat on? Cost for propane and cost/kWh for electric?

 

[3rdgendslmech]

Can't say on propane cost. But electric is 8.6 per Kwh.
Honestly I wouldn't need the heat on that much. I'm pretty tolerant of the cold. Just having a roof and 4 walls is a hell of an improvement vs being outside. Maybe at best 8 hours a week or 40 hours a month. And thats provided it's gonna be be below 35 and I'll be down there for more than an hour.