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We are in the planning stages for a 40x40 detached garage / shop I am building and need to know what will be required in Everett, WA 98204 to bring power to the building.

  • First off, I will need to run a high powered arc welder that currently is running off a 40A dual-pole breaker so that if I need to crank it up to its highest setting, I wouldn't have issues with the breaker popping when making long welds.
  • The new shop will also have a dual stack oven that you normally find in a kitchen that we use for powder coating parts.
  • Plus I want extra power available so if the oven is on, someone is welding, and someone else turns on the shop vac and all the lights, I am not popping breakers.
  • I also plan to add even larger machine shop type equipment with time, like CNC machine, lathe, and mill (that's hopefully not going to require 3 phase).

I read other articles that say tie into the house breaker, which is only a 200A panel. I added up all the existing breakers as-is, which come to more than 200 amps. But I do not really know how much power would actually be drawn on each circuit if everything in the house was to be turned on, appliance and heat wise (all lights are already LED to conserve power, and heaters are all 220v in each bedroom).

For example, the kitchen lights are only a handful of LED bulbs and outlets with no real power being drawn, but has a 20A breaker. Same goes for nearly every circuit off that panel. So I am probably sure I could run a sub panel off it.

But let's say there are 4 roommates in the house running every appliance, plus 3 people in the shop doing the same. I don't know if that would equal more than 200 amps. But the last thing I want to do is risk it.

So my questions are:

  • Can I run conduit off my meter on the outside of the house, instead of the existing house panel, and install another 150-200A panel 60' away in my shop?
  • I would like the ability, over time, to add a bunch of machine shop equipment like CNC machine, lathe, mill, and etc without having to do all new electrical service to the shop again 2-3 years later. What should I do to not have future issues?
  • Will conduit off the meter work instead of the house panel? If so what size conduit and cable to the new shop panel?
  • @Harper, looks like we were working on this at the same time and my save over-wrote some of your edits. Tried to catch them and add them back in. – fixer1234 Feb 13 '18 at 4:30
  • @fixer1234 thanks, you are living up to your name! I just added mostly paras, commas, and a few As for amps. – Harper Feb 13 '18 at 4:33
  • Since you are in the planning phase, plan the Ufer ground before you get concrete poured. After is too late. – Ecnerwal Feb 13 '18 at 14:32
  • You will read a lot of articles in wood/metalworking forums and publications which tell you to violate the Electrical Code. Beware of those. There is a certain "git-r-dun" / "to heck with the Man" rebellion, imagining Code was written by New York suits and not county fire marshals who pick through ashes. I'm happy to rebel, but Code is what it oughta be. – Harper Feb 13 '18 at 14:47
  • How many employees will be working in this shop at the same time? – Harper Feb 13 '18 at 14:55
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First. Next time you're welding and a breaker trips, put the tool down, walk away, and don't use the tool again until you have corrected the wiring defect (i.e. too-small wire for the tool and a breaker that is correct to protect that wire).

Talk to your power company about uploading that meter

Normally I would say "no way" because the meter itself and the service lateral (the pole line/underground from the transformer) would also need to have the capacity, and it usually doesn't.

However yours sounds like an all-electric house. I've seen all-electric houses provisioned for 400A. So it's possible the power company has already dropped a service lateral fit for 400A. In which case yeah, you could feed a second 200A main breaker right next to the meter pan and have that feed the garage.

Otherwise you will need to upgrade service, and depending on costs you may be better off getting a separate drop/meter.

This is completely determined by the power company and their peculiar situation on your block, we cannot possibly advise you other than to talk to them.

Given a project of this scope and safety impact, it goes without saying that you must communicate with the power company and must also pull permits with your local AHJ and do the inspection rigmarole. Generally AHJs are ok with people doing their own work, provided they are not a landlord (in which case no) or working commercially (in which case maybe). Doing this "gypsy" is out of the question.

You need to know more about exactly what your loads are

It sounds like you have only a coarse grasp of the electrical loads in your house. It is time for you to do a proper survey.

You are looking for watts or VA and need to eventually turn that into amps by dividing by volts. For instance a 2000W heater which runs on 240V is -- anyone, anyone, Bueller? 8.3333 amps at 240V.

For a resistive heater, Watts and VA are identical. For most others, VA is more important - Watts is what you pay for, VA is what trips the breaker. (to be more precise, VA is the power you must provision.) When different, use VA.

Get the numbers off the machines' nameplates. If no nameplate and they plug in, just get a $30 Kill-a-Watt and measure the machine underway. You'd be surprised what is almost nothing (coffee grinders) and what is a lot (coffee makers). Kill-a-Watt is not as helpful as nameplate, because nameplate is professionally tested.

Motors are special; get their running amps and horsepower. Locked rotor amps (a rather large number compared to the others) is not that important, nor is RPM.

Make a spreadsheet of the whole kit-n-kaboodle, you can do 240V and 120V loads separately. Then think about what is likely to be on at the same time (NOT heat and A/C hopefully) but even moreso, in the shop. Do you expect to use the lathe and planer at the same time?

Once you have done this survey, a bunch of really educational numbers will fall out the bottom and you'll know what to do next.

Think more about conservation

LED bulbs are nice, but it is "rearranging deck chairs on the Titanic" if you have resistive electric heat. I would go one of two ways on that. One is convert your resistive heaters to heaters that mine Bitcoin - you're still using a lot of electricity but at least you're getting paid. The other is go heat pump, which is ideal in a place freezes are rare; this will greatly lower your energy consumption and give you more headroom to run the shop.

  • That's the thing is its an average 4 bedroom house with average appliances that currently I live in by myself, so no power is being used unless by me. But I want to set up this system for worst case scenario where if I rent the house out to a large family who may not conserve power. I want us to be able to be back in the shop welding while parts are baking in the oven. I want the option to run whatever equipment is necessary without popping any breakers. I have looked into the CNC type equipment which are all 3 phase power. So apparently I have the option to pay $15k to bring down street to me – viragocafe Feb 13 '18 at 7:18
  • Or I need a phase converter sold by HP ratings like the CNC equipment but I am having trouble getting specs on the amount of power drawn besides a 3 phase rating which I thought meant 480v or 277v for lights, yet 1 CNC machine was 208v 3 phase. 1 guy posted ran a phase converter off a 200amp sub panel but didn't mention if that was using the whole panel or only a portion. I am curious if the 30hp phase converter means I can run multiple machines like a 20hp CNC & 10HP compressor off 1 converter. Would I need multiple phase converters? Would 3 phase power be the answer to all my power issues? – viragocafe Feb 13 '18 at 7:28
  • Or you can change the motors to single phase. On your manual tools, how do you plan to control motor speed? Are you not using VFD? VFD doesn't care whether it gets single or 3 phase input. 3 phase can be 208, 240 or 480, depending on the motor and how it's jumped. – Harper Feb 13 '18 at 14:58
  • VFD? There is a temp shop consists of mating 4 Costco carports & covering w/1 big tarp. When I say temp that was installed 12 years ago & worked great unknown to the local PUD a electrician friend helped run conduit off a dual 20 breaker off house box directly to a few outlets & fluorescent lights. I have lost contact w/him unfortunately & want new shop wired right as this breaker pops w/a welder having such small duty cycle. I planned to remove the existing circuit but if 3 phase is answer maybe leave it for regular tools that worked so well for all these years? – viragocafe Feb 14 '18 at 2:53
  • The welder I use is both 110 & 220, but it doesn't work well on 110 and draws too much power where you have to take constant breaks to point you let the welder sit longer than welding. Any welder who has a bunch of work to do & is laying down beautiful welds will tend to push it not wanting to break & start again & go from stacking dimes to not & can get away w/it until breakers pop reminding you its not a $4000 miller welder nor did you install that 220v circuit you always planned to. I want all this to be a thing of the past. Im on tight budget & know just enough to be dangerous. – viragocafe Feb 14 '18 at 3:16
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My take is that with the types of equipment that you are suggesting to install in this new garage/shop that you really should be having that building setup with its own main power panel and a power company line drop from the pole service directly to the garage.

That may very well entail running a separate power meter at the shop. But since some of the activities you are suggesting (such as powder coating parts) sound like a business it may actually be an advantage to have a separate meter and accounting for the business.

  • Someone else made the comment if I have a separate meter pole on my shop it will have to have a separate address to bill to considering the house is already being billed to the current address making it sound like I practically needed to subdivide my property just to get an extra metered service. Is it really all that complicated or will the PUD bill 2 separate meters on my property one for shop one for house on same bill? The property was built in 1963 then rezoned commercial w/a residential use about 15 years ago. So I do have the ability to live here & run my business out back in my shop – viragocafe Feb 13 '18 at 7:11
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    @viragocafe - The questions you ask in your comment above are ones you need to be asking your local power company. They are the ones that know how their billing systems work for multiple meters on one property. Certainly it has to be doable some how as duplexes are a common type of property and may use the address number as xxxA and xxxB just as an example. Address numbers are also usually not consecutive down the block so that additional numbers can be allocated for cases like this if needed. I would think there would be little need to sub-divide but again that is a local question to ask. – Michael Karas Feb 13 '18 at 9:19
  • Call a professional electrician and get an estimate. Along the way you will learn much. They will know any special local rules of your utility. I can't imagine any utility has a software problem billing two or more meters to a single address, that is very common. A customer making his own call to our utility would be transferred to "planning"--planning likely doesn't give many answers to an uneducated homeowner. While it is possible as a homeowner to get a meter set, it's more likely your utility is geared towards working with liscensed contractors than end users. – Tyson Feb 13 '18 at 13:21
  • I noticed the new meter had 4 lugs 2 for house panel & 2 that were open. So I figured we just connect to those 2 extra lugs & avoid putting the shop draw through the house. But Im hearing that strain may be too much for run coming from street to the house, so I should contact PUD to find out just what the capabilities are. We did installed new service in house we planned to asphalt over driveway so at same time we ran conduit to back of property for plans of future building. I could dig it up & make it turn & run to this shop instead it be half the distance to that conduit than house meter – viragocafe Feb 14 '18 at 3:33

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