LumberJocks

Initial planning on new detached workshop electrical

  • Advertise with us

« back to Focus on the Workspace forum

Forum topic by cootcraig posted 04-15-2016 03:53 PM 748 views 0 times favorited 12 replies Add to Favorites Watch
View cootcraig's profile

cootcraig

58 posts in 676 days


04-15-2016 03:53 PM

Topic tags/keywords: electrical detached feeder subpanel workshop

I’m looking into building a 12×16 detached workshop next to our home. There would be a 130 foot buried electrical cable from the home entry and panel to the workshop entry and sub panel. I will get a permit for electrical, but no building permit is needed for this size shed. I am looking for an electrician that will work with me on engineering and layout, do the panel hookups, and preinspect before code inspection(s).

Assuming I’m able to get service for the following power, I would like to get advice on what circuits to consider. Here are my first thoughts after reading threads on lumberjocks. Any actual planning awaits getting the electrician involved.

240V equipment

  • 30A
  • 30A
  • 50A

120V

  • 20A lights
  • 20A dust collection
  • 20A motors
  • 20A outside decking

Thanks.


12 replies so far

View Jerry's profile

Jerry

1768 posts in 1113 days


#1 posted 04-15-2016 04:20 PM

220 power tools usually require half the amperage of 110 running the same load. For example my bandsaw can be wired for either one. If it’s wired for 220 it draws 10 amps, if it’s wired for 110 it draws 20 amps. If you foresee needing as high as 50 amps, you’re more likely to need it on the 110 circuit. 12 X 16 is going to be a very small shop indeed. If you can swing it, I recommend you go 20 X20 at the very least.

-- There are good ships and there are wood ships, the ships that sail the sea, but the best ships are friendships and may they always be. http://geraldlhunsucker.com/

View tyvekboy's profile

tyvekboy

1342 posts in 2478 days


#2 posted 04-15-2016 04:20 PM

In my shop I put quad outlets every 5-6 feet. Every other one was on a different 120v-20amp circuit.

I would also consider 5/8 inch roofing sheathing for the walls. See my workshop for ideas.

-- Tyvekboy -- Marietta, GA ………….. one can never be too organized

View cootcraig's profile

cootcraig

58 posts in 676 days


#3 posted 04-15-2016 04:38 PM


If you foresee needing as high as 50 amps, you re more likely to need it on the 110 circuit.

I understand the different current draw for 110 vs. 220. What equipment is likely to be run on 220 and what would be a good maximum current for 220? I was thinking some motor equipment and possibly an electric welder.

What would you consider a good amperage for the largest 110 circuit? I’ve seen a chart that shows 110 current of 34A for 3hp and 56A for 5hp.


12 X 16 is going to be a very small shop indeed. If you can swing it, I recommend you go 20 X20 at the very least.

Sad but true. On this property I think 12×16 is the largest I can do. Some of the projects and work will be done outside. There is open area, but will not be able to build the shed any larger. It’s 12×16 or smaller.

View cootcraig's profile

cootcraig

58 posts in 676 days


#4 posted 04-15-2016 05:00 PM

Thinking about Jerry’s reply, another possible circuit list:

240V

  • 20A
  • 20A
  • 40A

120V

  • 20A lights
  • 20A dust collection
  • 20A outside decking
  • 20A misc.
  • 40A motors
View cootcraig's profile

cootcraig

58 posts in 676 days


#5 posted 04-15-2016 05:03 PM



In my shop I put quad outlets every 5-6 feet. Every other one was on a different 120v-20amp circuit.

I would also consider 5/8 inch roofing sheathing for the walls. See my workshop for ideas.

- tyvekboy

Those are both good ideas. Given the small space, I planned to leave the interior rough to allow flexible storage on the wals

View AZWoody's profile

AZWoody

697 posts in 689 days


#6 posted 04-15-2016 07:07 PM

I have a 20×40 shop and have the circuits as follows.

240V : 30A Dust collector 30A North wall tools 30A South wall tools

110V : 20A Lights and utility plugs 20A North wall machinery 20A South wall machines

The lights and plugs that are on the same circuit power shop radio, battery chargers, etc. The other plugs are for all machinery whether stationary or handheld. You really should consider 240V for a dust collector. If you’re starting from scratch, it’s better to get the best you can afford and have the power for it now rather than starting with a 110v, getting something small, throwing money on upgrades and mods. In the end, you will be happier.

I don’t see the need for a vast amount of circuits for plugs, especiallly if you’re the only one working and will only have one machine going at a time. I have seen some people get overboard and run a breaker for practically every machine. It’s rare, but some people do that and there really isn’t a need.

I do like the idea of the 50A for the welder.

View Nezzerscape's profile

Nezzerscape

25 posts in 328 days


#7 posted 04-15-2016 07:26 PM

Because you are running a sub-panel if think it is not a mater of what you want but what you can have. I would run as much juice as you can. Today you might not need 50A but then you get a new dust collector and now you cannot run that and the TS as the same time. (yes I know you do not need 50A for both those in a 20×16 shop)

What can you pull from your main? Can you have a separate drop from from the pole (that is what I did but the pole is next to my shop)?

View cootcraig's profile

cootcraig

58 posts in 676 days


#8 posted 04-15-2016 07:27 PM

A revision based on AZWoody comments.

240V

  • 30A dust collection
  • 50A equipment including high power like welder

120V

  • 20A lights
  • 20A outside decking
  • 20A misc. – 1/2 of shop
  • 40A higher power motors – 1/2 of shop

I figure only one piece of 240V equipment other than the dust collector would be used at a time.

Given the size of the shop segregating the 20A and 40A 110V will make it easy to know which is which when I care.

View cootcraig's profile

cootcraig

58 posts in 676 days


#9 posted 04-15-2016 07:30 PM



Because you are running a sub-panel if think it is not a mater of what you want but what you can have. I would run as much juice as you can. Today you might not need 50A but then you get a new dust collector and now you cannot run that and the TS as the same time. (yes I know you do not need 50A for both those in a 20×16 shop)

What can you pull from your main? Can you have a separate drop from from the pole (that is what I did but the pole is next to my shop)?

- Nezzerscape

Good point, I’ll be awaiting getting an electrician onsite to determine capacity and options.

This is residential and all electric is buried.

View tblank's profile

tblank

59 posts in 2435 days


#10 posted 04-15-2016 07:42 PM

I would say a 50A for the 240 supply is a must with a welder and 30A for a big air compressor. Also, if the plugs are on a separate breaker than the lights, it will be handier in a tripped breaker situation. At least you will be able to see when the plug breaker trips.

View cootcraig's profile

cootcraig

58 posts in 676 days


#11 posted 04-17-2016 06:46 PM

Lot’s of good ideas, they are helping me consider my options. While no building permit is required for a 12×16 shed my wife has not given final approval. The next step on construction is finding an electrician to work with. My current thought is that the workshop service would be between 60 and 100A. With the electrician I will get estimates on panel work and power availability.

View AZWoody's profile

AZWoody

697 posts in 689 days


#12 posted 04-17-2016 06:58 PM

One thing to consider is your shop layout. You might want to have a a plug in the floor and or ceiling if you already have an idea where you want things.

Maybe even run some ducting for the dust collector under the floor as well.

Have your say...

You must be signed in to reply.

DISCLAIMER: Any posts on LJ are posted by individuals acting in their own right and do not necessarily reflect the views of LJ. LJ will not be held liable for the actions of any user.

Latest Projects | Latest Blog Entries | Latest Forum Topics

HomeRefurbers.com