New Shop space- electrical considerations

[mongo]

I mentioned recently in another thread about my new shop space.  I am looking for input for ideas and input on the electrical before I have the electrician out.  My honey do list is growing rapidly so I need to get moving on this. I have enough tools that require 30 amp 220 that I am planing on running all my 220 in 30 amp.....  and a bunch of 110 outlets. This is a garage but I will not share the space with cars, I am sure however that I will end up changing the layout as I figure out the larger shop space and change/ acquire some tools.


So what things did you do in your shop that you are happy about?   What do you wish you had done?  What was a bad idea?  How large a sub panel did you end up with? 

 I know this is broad but throw any ideas at me,  I learn a lot by listening to you all.

[fredhargis]

There are ways to calculate amp load, but honestly most hobbyists can do quite nicely on 100 amps. Actually, even 60 amps, but once you're doing the work the increased cost of 100 (versus 60) is fairly negligible. One thing I will mention: I, too, have a number of tools that take 30 amp circuits, but I'm still doing most of my 240 in 20 amp. The reason is cost. 30 outlets/plugs aren't just slightly higher than 20, they are incredibly higher. So while I will have a number of 240V/30 amp circuits, they will mostly be 20 amp. One thing I did in my last shop was install all the 120V outlets in 2 gang boxes with 2 duplexes. Then, each duplex was on a separate circuit so I could plug 2 heavy draw tools into the same location, one on each duplex, without tripping breakers. Wiring that was a colossal PITA. As I do the current shop the jury is still out on whether I'll run 2 circuits to each box. Also, put your outlets 52" up so you can lean things against the wall and not block them. I'll be interested to see the other opinions on this, since I'll be starting mine in another month or so. BTW, I had 100 amps in my last 2 shops, and will have 100 in this one. Even with a welder I've never been short on power.

[Herebrooks]

A few recommendations I would make is to run your electric in external conduit. We woodworkers are famous for changing out and moving around machines. It's simple to add or move conduit and pull new wire when needed, or make a 110 line into a 220 line. This is true of lighting as well. As you get to know your new workspace, you may need to add more light in certain areas.
Here in North Carolina, it is required that all outlets in a shop or garage be on a GFI. That doesn't mean you have to have one on each outlet, only that any additional ones need to be tied to one.
Good luck!!!

[Admiral]

A few things not already mentioned...  keep your lighting circuits separate, if you blow a breaker with a machine you don't want to be in the dark; make your 120v circuits 20 amp (12ga wire is a bit harder to work with, I know), as sometimes start up draw on things like compressors will trip 15 amp (and with GFI, you're in a garage and while code may require it, I don't know); install the outlets (and spec Hubbell or similar quality) with the ground prong at the top, as plugs get loose in a shop environment and things may fall into the plug area that can short out if installed the "normal" way.

I've wired two shops now, and 100 amp is all I ever needed (big iron TS, Jointer, Planer; lathe, DP, etc.) as at most you are running only two machines at once; you didn't say which of your equipment calls for 30 amps, and unless you have 5hp machines, 20 amps are plenty for 2 and 3hp machines, at least in my experience.

[joe1086]

Consider placing the some/all of the outlets at bench height or higher.

[rwe2156]

I recommend surface mounting all your electrics w/ conduit.

It makes changing/adding outlets SO much easier.

[TDKPE]

Determine the worst-case scenario for lights, machines, dust collection, heat/vent equipment, chargers, portable tools, compressors, etc. that can all run simultaneously.  From each load, determine either watts (mostly resistive loads, like lights and electric heat), or motor current in amps multiplied by the operating voltage (volt-amps), and add them all up.

Divide by 240V to get the total load on the panel feeder, assuming current is balanced on both hot legs.  Which they won't be.  So for that reason, and some others, tack on at least 25%.  That's the minimum feeder ampacity you should be using.  

Panel ampacity can be higher than the feeder circuit (you can use a 100A panel on a 60A feeder), with or without main breaker (it's a subpanel, and is disconnected at the feeder breaker in the main panel).  Many folks use a 100A or larger panel to get the greater number of breaker slots.

Remember that 60A 120/240V power is 120A at 120V (60A at 240V, or any combo that doesn't exceed 60A on either leg), which is a LOT of power for a one-person shop.  A typical 1-1/2 hp contractor saw is less than 20A at 120V.  My 3 hp Unisaw is rated only 12.4A at 240V, and that's full load, which I never even come close to, but regardless, it's still only 1/5 of the available 60A in my shop.

Also keep in mind that you can put multiple receptacles on a single 240V branch circuit (legally), for machines you can't or won't use simultaneously.  I only have one 20A 240V circuit for my big stuff, but I really can't (or won't) run my RAS with my lathe with my Unisaw.  So there's no need, in my case, for three circuits.  BUT, if you're having it inspected, you may have to convince the inspector it's only so you can locate a machine in different places, as some get a little carried away when it comes to 'fixed in place' stationary equipment, which those machine really are not, but it's an argument that's hard to win with some inspectors.  If it's permanent heat or A/C, it needs its own circuit.  If it's a saw with a cord and plug and UL listing, its a tool in a home shop, and doesn't need its own circuit, any more than your circular saw, which may draw just as much current under heavy load.  AFAIC, at least.

[BloomingtonMike]

I did the work myself do some of this may not be applicable to hiring an electrician. lso this is a big shop for me so I had lighting and number needs you will have to scale to your install.

I bought 200amp panels with 42 spaces. I ran 200amp to the shop but right now I also have electric in floor heat to account for. More important is the number of CB spots. Mine are 42space GE Goldmark panels - They are about $100ea at Menards. I actually have two single phase panels - one on north wall and the main panel on south wall. I ran 2-2-2-4 up and over in the ceiling to feed the north wall panel.

I am mounting the panels on the outside of the wall but all current wiring is in wall. Gives me the ability to run external conduit later if needed.

I have Lighting in 4 zones on 4 sets of two way switches at the two doors I use most often.

I don't have any two 240V receptacles next to each other on the same circuit. No four 120V outlets are on the same circuit. Also have compressor and DCs on their own separate circuits.

Also my east and west halves of the building (and north and south are separated too because of 2 panels in the shop) are on different circuits so two guys working are not going to impact each other.

I bought used L6-30R receptacles in bulk on eBay that are taken out of data center installs. All are Hubble. All have been perfect. I always offer around $5 each but I typically was buying 20 or more at a time.

I did 10ga for 240V and 12ga for 120V. Easy to buy and standardize on two sizes and buy in bulk.

I put outlets in the ceiling for above tool access in the areas where I expect to have benches and tools.

Put a switched outlet up high for drop down vac hos for sander - hose on a cable - suspend a shop vac up high. No hse dragging on bench edge.

I ran outlets up high by my garage door torsion bars and use jackshaft openers that do not require a bar down the middle of your shop.

I ran a line for emergency light incase power ever went out

I have implemented lots of other things I did but this is prob enough for what you want LOL.

Sorry for the long list.

Mikie

[mongo]

A few things not already mentioned...  keep your lighting circuits separate, if you blow a breaker with a machine you don't want to be in the dark; make your 120v circuits 20 amp (12ga wire is a bit harder to work with, I know), as sometimes start up draw on things like compressors will trip 15 amp (and with GFI, you're in a garage and while code may require it, I don't know); install the outlets (and spec Hubbell or similar quality) with the ground prong at the top, as plugs get loose in a shop environment and things may fall into the plug area that can short out if installed the "normal" way.

I've wired two shops now, and 100 amp is all I ever needed (big iron TS, Jointer, Planer; lathe, DP, etc.) as at most you are running only two machines at once; you didn't say which of your equipment calls for 30 amps, and unless you have 5hp machines, 20 amps are plenty for 2 and 3hp machines, at least in my experience.

Thank you for the input,  definitely all 20amp on all the 110v circuits.  Who else would be hubbell quality?

 The Tablesaw is 5hp, the DC requires 30amp, and eventually the bandsaw will require 30amp as well.  The jointer and planer are each 3hp and could run on 20 amp.  Everything except the DC shared the same 30amp outlet in the old shop so everything already has a 30amp plug.  For simplicity I was planning on running all 30amp so anything can plug in anywhere as arrangements change.   

Thanks again

---

I did the work myself do some of this may not be applicable to hiring an electrician. lso this is a big shop for me so I had lighting and number needs you will have to scale to your install.

I bought 200amp panels with 42 spaces. I ran 200amp to the shop but right now I also have electric in floor heat to account for. More important is the number of CB spots. Mine are 42space GE Goldmark panels - They are about $100ea at Menards. I actually have two single phase panels - one on north wall and the main panel on south wall. I ran 2-2-2-4 up and over in the ceiling to feed the north wall panel.

I am mounting the panels on the outside of the wall but all current wiring is in wall. Gives me the ability to run external conduit later if needed.

I have Lighting in 4 zones on 4 sets of two way switches at the two doors I use most often.

I don't have any two 240V receptacles next to each other on the same circuit. No four 120V outlets are on the same circuit. Also have compressor and DCs on their own separate circuits.

Also my east and west halves of the building (and north and south are separated too because of 2 panels in the shop) are on different circuits so two guys working are not going to impact each other.

I bought used L6-30R receptacles in bulk on eBay that are taken out of data center installs. All are Hubble. All have been perfect. I always offer around $5 each but I typically was buying 20 or more at a time.

I did 10ga for 240V and 12ga for 120V. Easy to buy and standardize on two sizes and buy in bulk.

I put outlets in the ceiling for above tool access in the areas where I expect to have benches and tools.

Put a switched outlet up high for drop down vac hos for sander - hose on a cable - suspend a shop vac up high. No hse dragging on bench edge.

I ran outlets up high by my garage door torsion bars and use jackshaft openers that do not require a bar down the middle of your shop.

I ran a line for emergency light incase power ever went out

I have implemented lots of other things I did but this is prob enough for what you want LOL.

Sorry for the long list.

Mikie

Thank you for all the great input.  No list too long at this point.  I have some specific ideas but I hate to tie myself down when I might be missing some great thoughts.  For example I had never seen jackshaft openers before.

 Not sure how much what percentage of this is going to be my work or electricians at this point.  Depends what the quotes come in I guess.  I set aside some money for the shop in this move and I want to make sure I end up with a better planned shop than the first one.  Sp all ideas are welcome.

---

Determine the worst-case scenario for lights, machines, dust collection, heat/vent equipment, chargers, portable tools, compressors, etc. that can all run simultaneously.  From each load, determine either watts (mostly resistive loads, like lights and electric heat), or motor current in amps multiplied by the operating voltage (volt-amps), and add them all up.

Divide by 240V to get the total load on the panel feeder, assuming current is balanced on both hot legs.  Which they won't be.  So for that reason, and some others, tack on at least 25%.  That's the minimum feeder ampacity you should be using.  

Panel ampacity can be higher than the feeder circuit (you can use a 100A panel on a 60A feeder), with or without main breaker (it's a subpanel, and is disconnected at the feeder breaker in the main panel).  Many folks use a 100A or larger panel to get the greater number of breaker slots.

Remember that 60A 120/240V power is 120A at 120V (60A at 240V, or any combo that doesn't exceed 60A on either leg), which is a LOT of power for a one-person shop.  A typical 1-1/2 hp contractor saw is less than 20A at 120V.  My 3 hp Unisaw is rated only 12.4A at 240V, and that's full load, which I never even come close to, but regardless, it's still only 1/5 of the available 60A in my shop.

Also keep in mind that you can put multiple receptacles on a single 240V branch circuit (legally), for machines you can't or won't use simultaneously.  I only have one 20A 240V circuit for my big stuff, but I really can't (or won't) run my RAS with my lathe with my Unisaw.  So there's no need, in my case, for three circuits.  BUT, if you're having it inspected, you may have to convince the inspector it's only so you can locate a machine in different places, as some get a little carried away when it comes to 'fixed in place' stationary equipment, which those machine really are not, but it's an argument that's hard to win with some inspectors.  If it's permanent heat or A/C, it needs its own circuit.  If it's a saw with a cord and plug and UL listing, its a tool in a home shop, and doesn't need its own circuit, any more than your circular saw, which may draw just as much current under heavy load.  AFAIC, at least.

Great stuff thanks!

[Toscageoff]

Greetings

Install sockets  4 feet apart and 52 inches above ground

I recommend installing an outside weatherproof socket [for ease of use for circular saw when cutting down wide boards etc and other outside tools like a lawnmower] and an external earth/ground cable