New shop electric service...

[Clisby Clark]

My electrician asked me if a 20 amp service would be OK for my new shop or if I needed to bump up to a 30. I will be running a small cyclone, cab. saw, 8" jointer, band saw, etc. No really monster stuff. Only two big machines at once (one being the DC). Max two people at a time. He says I can save on wire with the 20 amp service, but I want to make sure I've got enough juice. Any advice is welcomed. Thanks

[David G Baker]

I would recommend a minimum of 60 amps service with my not knowing what other hobbies you have. It is, in most cases, cheaper to plan ahead when you do the initial install rather than upgrade in the future, that is unless the price of copper goes back to where it should be.

[Tom Veatch]

Only one circuit?

Maybe your electrician isn't aware of what you're going to be using in the shop. Tell him/her what machines are expected to be involved, the motor sizes now and projected, and whether you ever expect to see any simultaneous usage - a dust collector and a table saw for example.

My guess is that he/she will recommend significantly more than a single 20amp circuit.

[Mike Cutler]

Clisby

Hmm... I hope that you and you're electrician are just miscomunicating.

If he is asking if you want a total of 20 amp service available for the entire shop needs. The answer is no. I have 30 amps and it's definitely not enough when lighting is factored in.
30 amps has been limiting for me when it comes to machine sizes and selection. I'm looking to upgrade mine to at least 60 in the next year or so.

[John Keeton]

I'm no electrician - won't even play with the stuff! But, seems with the work I have had done in the past in various situations, the cost difference of running a larger "service" is in the size of wire pulled for the service and the size of the main breakers. Everything after that is a factor of the panel box, breakers, and how many circuits/outlets, etc. that one puts in.

I agree 60 amp is probably enough, but why wouldn't you run at least a 100 amp service? That should be enough for all your future needs - even for some heat/cool. A 100 amp. panel box with breakers is probably cheaper anyway and you would probably use it even if you ran a 60 amp supply just for cost.

It just seems like this isn't the time to go cheap. You can go slow with the expansion of your interior supply (circuits and outlets), but at least you would have the capacity. The labor cost of running the supply line should be the same.

My DC system is on a 30 amp circuit, which seems like it pretty much precludes a 20 amp supply!?

Caveat - I don't know squat about electricity - just commenting from the money I have paid electricians over the years and the choices I have made at the time given the various cost factors.

[Anthony Whitesell]

I'll have to agree with Mike. I hope that's a miscommunication (or misinterpretation) from the electrician. I started with a single 20 amp service in my basement shop and if I didn't start the machines in the right order the breaker would trip (ie., start DC wait for the spin-up to finish then start the tool and I was the only one in the shop). The DC is now on a separate 20 amp service from the tools. So I would have to say that you'd need a 20 amp circuit for the DC and one 20amp circuit per person so that each of you can operate tools on separate circuits and not worry about tripping the breakers.

[Lee Koepke]

I have a 100A subpanel that runs most of the stuff in my basement, some shop, some 'residential entertainment' ....

the 20A size you are talking about is generally referred to as a circuit, multiple circuits make up a service.

a 20A circuit can have probably one or two of the machines you talked about, but your electrician needs to see the motors you plan on using. I had a 20A circuit at my old house, and my table saw would trip the breaker with its startup amps .... so I upgraded that specific circuit. My TS is now 220V and I have a dedicated circuit for that.

If you have the means, increase the service size as mentioned above, with an additional 100A panel for example, you can run new circuits at a later date if your needs change.

[Mike Wilkins]

You could power a run of overhead lights and maybe a router with 20 amps. But this is not nearly enough to power a shop. A minimum of 60 amps is what I would recommend, but 100 amps would be even better. Think future expansion in shop size or machinery upgrades.
I have a 16 X 24 shop with an attached 16 X 16 storage shed, and I have installed a 100 amp panel.
3 240 volt outlets and the rest 115 volts.

[Chris True]

It all depends on what machinery you have of course but arguing a bit against the small substation crowd :) 100 isn't really needed for most small shops. You may well have 100 amps worth of circuits or more if you add em all up but won't use it all unless you've got a bunch of 5 hp tools you run at the same time.

50 amps should be adequate if you're tools are limited to 3 hp and it's a one person shop. Typically you'll have a 15 amp circuit or two for lights, those won't be loaded 100% and they are 110V so 2 15 amp circuits loaded to 100% counts as 15 or your 50 amp circuit. In actuality it'll more like 7 or 8 max with a lot of lights. Then you've got a 3HP DC and a 3HP tool, 12 - 14 amps each max under full load. So in actuality your load is in the 30 amp range. You might install 5 20 amp 220V circuits but unless you run em all at the same time fully loaded you don't need "100 amps". You might want a nice BIG panel so you can fill it with lot's of circuits that get used 5 minutes at a time but it would be served by a 50 or 60 amp feeder.

[Luther Oswalt]

I have 200 amp service in my shop as I have large air compressor ... welder ... etc. ... but I would not have less than 100 amp. in any shop that I would build! Just me ...