Help Me Design/ Build a Shop

[LittleBittyBigJohn]

most likely you are correct and 100 amps for the shop with 200a - shop load for the house will be fine but it depends on what you are running at the same time as well as what is going on in the house at the same time. someone using the stove/ oven while some one is taking a shower can draw a lot of power with ac/heat on top of that.
also circuit breakers don't just trip when hit 201 amps for a few min they will take 10 min or so at 230 amps (more current less time) but on the other side unless they are 100% rated and most are not, that 200 amp breaker will trip at 80% or 160 amp after 4 hours continuous load (give or take).

as i said before you most likely will not have a problem with your load.

Good news with that is hot water and stove are both gas. Oven is electric so no getting around that one.

 

[LittleBittyBigJohn]

Also, I just thought about this. Realistically anything that I'm going to be using in the shop has been used in my house garage at one time or another. More lighting yes, possibly a bigger air compressor. That makes me think about it a little differently.

 

[GSVette]

I ran a 400 (320)A service at my shop- installed a dual lug base and a 200A commercial panel in the shop. Am in process of trenching to the house build site from the shop- will pull another 200A set from the dual lug meter base to the homesite for its breaker panel. 1 meter for both house and shop.

 

[ericm979]

I agree to a point, but I can have running the compressor, lights, heat(or possibly AC where the OP is), dust collector, and wide belt sander all at once and those are all on 30 or 40A 240 circuits, except the lights & heat (not that they draw full amps). A 200A service has the advantages of max number of breaker spaces available, which is nice given the 240v ones take 2 spots and you can end up with a number of them.

The number of circuit breaker slots in the building's panel does not depend on the service breaker size. The sum of the breakers in the panel is often much larger than the rating of the main breaker, because not all of that stuff is on at the same time and it doesn't draw what it's breaker says. For houses there's a complex formula that the electrician uses to calculate the load and thus the service amps needed. What's really interesting is that for 240v stuff that aren't normal household items you're pretty much on your own. It's up to you and the electrician to figure out which ones could be run at the same time and what their loads are.

If you had a 60 amp feed to a building you could use a 40 slot panel if you wanted. You don't have to fill all the slots of course. But if you had a lot of 240v equipment and were only going to run one at a time, you could use up a lot of the slots. (240v stuff is often supposed to be hard wired, each to its own breaker)

Also the service amps to a building is determined by the smallest breaker on the feed to the building. For example my main panel has a 125a breaker for the feed to the house and a 35a one for the well. I can put a "200amp" panel in my house with a 200a main breaker, which is totally to code. The 200a breaker in this case is really a disconnect. I'd still have a 125a feed to the house.

When planning my shop I used an on line version of the formula and got a number for house + shop + barn that was pretty close to what my electrician came up with. I'm using his work for the permit of course but mine was a useful ballpark.

One thing to keep in mind is power for electric car chargers. You might not be planning on getting one any time soon but in 10-15 years who knows?

 

[DaBear3428]

The number of circuit breaker slots in the building's panel does not depend on the service breaker size. The sum of the breakers in the panel is often much larger than the rating of the main breaker, because not all of that stuff is on at the same time and it doesn't draw what it's breaker says. For houses there's a complex formula that the electrician uses to calculate the load and thus the service amps needed. What's really interesting is that for 240v stuff that aren't normal household items you're pretty much on your own. It's up to you and the electrician to figure out which ones could be run at the same time and what their loads are.

If you had a 60 amp feed to a building you could use a 40 slot panel if you wanted. You don't have to fill all the slots of course. But if you had a lot of 240v equipment and were only going to run one at a time, you could use up a lot of the slots. (240v stuff is often supposed to be hard wired, each to its own breaker)

Also the service amps to a building is determined by the smallest breaker on the feed to the building. For example my main panel has a 125a breaker for the feed to the house and a 35a one for the well. I can put a "200amp" panel in my house with a 200a main breaker, which is totally to code. The 200a breaker in this case is really a disconnect. I'd still have a 125a feed to the house.

When planning my shop I used an on line version of the formula and got a number for house + shop + barn that was pretty close to what my electrician came up with. I'm using his work for the permit of course but mine was a useful ballpark.

One thing to keep in mind is power for electric car chargers. You might not be planning on getting one any time soon but in 10-15 years who knows?

actually the NEC is very stringent on demand load calculations, if it is not listed equipment you have to figure it at 100% in a lot of cases so we work hard to try to fit a piece of equipment into a known load profile to get a demand factor. There are 240 volt receptacles and you are allowed to run them just like other outlets (more than one to a circuit) if your demand calculations show that the circuit is not overloaded.
the online calculations sites are usually a good start on demand calculations, but like everything else garbage in == garbage out so beware.

also for some loads you have to calculate the demand @ 125% of the connected load (it has to do with the 80% max continuous rating of most circuit breakers)

sorry if i'm comming of as mr know it all, just trying to pass on my 30 years as a electrical P.E.

 

[DaBear3428]

Also, I just thought about this. Realistically anything that I'm going to be using in the shop has been used in my house garage at one time or another. More lighting yes, possibly a bigger air compressor. That makes me think about it a little differently.

then it sounds like you have a good handle on it good luck with the new shop, there is nothing like having a place to go and get things done where no one has borrowed that one tool that you have to have to finish your project that you now have to spend 2 hours asking everyone have they seen it, only to be met with blank stares, then to find it laying in the dirt where you son decided to disassemble the lawn mower only to leave the air cleaner laying in the dirt next to it. just for the record how do you use a $200 torque wrench to take a spark plug out of a mower?

 

[EddieWalker]

... There are 240 volt receptacles and you are allowed to run them just like other outlets (more than one to a circuit) if your demand calculations show that the circuit is not overloaded.
...

I didn't know this. I'm adding a 3 car attached garage to my house and I'm planning on running a 220 outlet for my welder. I recently acquired a 220 volt air compressor that I was going to run a separate 220 line to. Since they will be about 15 feet apart from each other, and never used at the same time, is there any reason I can't have them on the same breaker?

 

[DaBear3428]

I didn't know this. I'm adding a 3 car attached garage to my house and I'm planning on running a 220 outlet for my welder. I recently acquired a 220 volt air compressor that I was going to run a separate 220 line to. Since they will be about 15 feet apart from each other, and never used at the same time, is there any reason I can't have them on the same breaker?

are both receptacles rated for the amperage of the circuit? the compressor can be directly connected.
NEC 430.24 covers the load calculation.
this is out of the 2017 NEC but is still the same in the 23.
the NFPA has in their wisdom to not allow PDFs of the newer codes (they were losing money, never mind the safety of having more people access to the code)
you just need to size the conductors and overcurrent protection to provide the required current per the calculation and all of the components need to be rated for the current also.
short answer is yes you can.

BTW I finished HS in Henderson, went to Kilgore JC and worked in Lufkin for a few years

sorry had to remove the attachment due to copyright.
post name plate info on the loads and i will size it for you.

 

[dstig1]

Since I don't think Eddie has any inspections where he is, the quick answer is you can do whatever you want... DaBear will be able to help you better with the load calcs if you want to follow code to the letter.

I did a few 240V circuit runs with multiple outlets on them down the sides of my shop for the less frequently used items. The heavy use items all get their own circuit just for peace of mind and simplicity. So if I roll out my big shaper to cope and stick doors, I can plug it in a few places. Same thing with my metal band saw...and my wood bandsaws too. Now the air compressor and dust collector? Those get their own circuits for sure as they can run at any time and are heavy loads. Same reasoning on the table saw, jointer, planer and (mini)wide belt sander.

Do you really want to be running your welder and have the comp kick on and trip the breaker on you mid-weld? Run yourself a 60-100A subpanel instead and then pull the comp on it's own circuit and add a few 240v outlets on another circuit so you can plug your welder or something else in wherever you want.

 

[civilian]

OP, in my recent shop build for wood working the electrician ran a 200a service. Panel has like 40 spots in it. All of the 240v tools have their own circuit to run on. One circuit may have 3 outlets on it. But no multiple tools running at the same time. Dust collector on its own circuit because it runs with all tools. Mostly a one person shop, but depending on tools and nearest outlet, a second person could run a tool, but my DC would not keep up. Just some thoughts. Jon