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Advice on power & air layout

trochoidalpath

Cast Iron
Joined
Jan 17, 2016
Roughing in power in some new shop space and I am having a moment of self-doubt.

  • 120V power receptacles: 2 duplex, every 8 feet, mounted at cabinet countertop height + 3 inches
  • 240V power receptacles: 1 each 30A 1-phase and 3-phase, every 8 feet, mounted at 6.5 feet above floor. IEC 60309 (pin-and-sleeve style) receptacles, angled 15 degrees off the wall and pointed down.
  • Separate 240V power receptacle 60A 1-phase near the big door, mounted at the same height, in case I need to get some welding done
  • Compressed air: Transair hard line run 8" below the ceiling around the perimeter of the room in a big loop. Drops are every 8 feet and terminate 6 feet above the floor; each drop has a valve ahead of a duplex 45-degree air fitting.

Placement and quantity sound good? Anything I should be thinking here about that I'm not? I'm definitely optimizing for flexibility, not entirely sure where equipment is going yet.
 
One thing I strongly believe is to have the electrician run separate grounds wherever possible. Machines with a lot of electronics generally don't like sharing grounds with other equipment.
 
Why the IEC receptacles? Why not regular old NEMA twist lock receptacles? On the 240 V single phase- why? just pull any 240 V single phase off your 3 phase receptacles if you need it, unless you have a bunch of 240 V single phase requirements- IMO, you will never use these or very seldom. Make sure to pull a neutral into your 3 phase conduit run if it's separate conduit- it will come in handy later on when you need 120 v on a machine.
 
My rationale for the 240V 1-phase: the 3-phase is coming off a Phase Perfect, not the utility. I was worried about putting too much load on one of the phases and getting myself into trouble that way. Is that goofiness? (I'm a pretty awful electrician so it's very possible I'm missing something basic.)
 
I suspect this is a dumb question, but I have to ask.

Re pulling 240 single phase from a 3 phase receptacle, does it make any difference that the two 3 phases legs are 120 degrees out of phase vs 180 degrees from a single phase feed? Does the motor run smoother if the voltage never drops to 0?
 
Roughing in power in some new shop space and I am having a moment of self-doubt.

  • 120V power receptacles: 2 duplex, every 8 feet, mounted at cabinet countertop height + 3 inches
  • 240V power receptacles: 1 each 30A 1-phase and 3-phase, every 8 feet, mounted at 6.5 feet above floor. IEC 60309 (pin-and-sleeve style) receptacles, angled 15 degrees off the wall and pointed down.
  • Separate 240V power receptacle 60A 1-phase near the big door, mounted at the same height, in case I need to get some welding done
  • Compressed air: Transair hard line run 8" below the ceiling around the perimeter of the room in a big loop. Drops are every 8 feet and terminate 6 feet above the floor; each drop has a valve ahead of a duplex 45-degree air fitting.

Placement and quantity sound good? Anything I should be thinking here about that I'm not? I'm definitely optimizing for flexibility, not entirely sure where equipment is going yet.

I would add some stubs onto your air plumbing for future uses. Also, a couple water traps with valves, even if you have an air dryer.
 
When running your airlines, make sure to put in some drop legs with drain valves, and always come off the top of your trunk line to keep moisture out of the drops.
 
RE: Air -- second adding stubs for future expansion, water traps/drains, coming off top of line when feeding to machine/quick disconnect.

Would add:
Plumb lines to drain any moisture to a drain valve.
Add valves to main run in corners to allow isolating a section while still running in rest of the shop.
Add a large tank in corner opposite compressor, and smaller tanks near air-intensive machines.
 
I suspect this is a dumb question, but I have to ask.

Re pulling 240 single phase from a 3 phase receptacle, does it make any difference that the two 3 phases legs are 120 degrees out of phase vs 180 degrees from a single phase feed? Does the motor run smoother if the voltage never drops to 0?

If you go back to the panel, the two 240 (110 v to gnd for the non- stinger legs) volt single phase conductors come off two of the 3 phase conductors/lugs- you are just leaving one wire behind for a single phase branch circuit.
 
I have my 115V outlets at about five foot internals and many of them have power strips on them. I suggest more outlets. As for the 230V outlets, I put them wherever the equipment is. Most of them are about 4' above the floor (above counter top level) or on the ceiling.

I have not run my air yet so I will be looking here for ideas.



I space my receptacles at 10' intervals. Because conduit comes in 10' lengths.
 
The first shop I built put duplex outlets every 10' and air drops everywhere. There was alot of stuff that never got used. A lot of air quick connects rusted solid before I ever used them.

Leased a couple buildings where I put no more into than required. Lots of extension cords and shady electrical. But it got the job done just fine.

My "forever shop" that I've built over the past few years has busway 16' up the crane columns which are 30% in from the side walls. I haven't put any 120 outlets on the walls yet. I was going to, but the middle of the shop is the action area so I just put lots of outlets on each column (8 in the main bay). Don't really need the 120 all that much. Most of my stuff is 3 phase.

I find everything changes continuously. I'm always adapting to a new process or replacing a machine as it ages so there's no point in making wiring or plumbing too permanent.

I really, really like busway though.

I use the 30A 240V twist locks for everything under 5HP in my shop. I think they work pretty good. I have corded drops and wall recptacles.

For air I like copper because I can go down to lowes and buy whatever I need when I need to modify my air lines. And it lasts forever and looks good even when I paint right over it.

I also found Unistrut to be real helpful when running all this shit. I have air, water, power, crane conductors, RS232 and even speaker wires running all over and unistrut makes it clean.
 
Another thought on air... don't go too small diameter for your main run. Second thought add more shut off valves in the system. It is so nice to be able to shut off and isolate a small portion of your air system for repair or additions. Most shops I have worked in had ONE maybe two shutoffs if you are lucky. Sucks ass having to shut down the entire air system to change one fitting.
 
I'd raise the height of your 120V plugs. Cabinet plus 3" doesn't do any good when stuff piles up on the bench. I'd have them at 50" from the floor to the bottom of the box.
 
  • Compressed air: Transair hard line run 8" below the ceiling around the perimeter of the room in a big loop. Drops are every 8 feet and terminate 6 feet above the floor; each drop has a valve ahead of a duplex 45-degree air fitting.

This is a recipe for water. Take the drop of the top of the main line, not the bottom. At user level, either put a T pointing off to the side or put a manifold, which gives you four or more ports facing sideways. Off the bottom of the T or manifold, put a stub pipe and then a ball valve. Any water that collects in the drop will end up at the bottom, past where you're drawing the air off, and then you just crack the valve to drain.

With a drop off the bottom of the main line and then a double 45 degree QD fitting, water will be sitting in the QD fittings and corrode them.
 
A bit of a luxury, but I ran 4" gutters around the entire perimeter of my shop, makes it trivial to pull new circuits and adapt with new drops as needed in the future.
 
Where are you at in Cali? I wired my own two shops I had there and a couple small shops for friends. I was in Riverside county the inspectors there were a complete joke. I would keep as much as you can on the down low. If it is a new shop get the basics permitted and bought off and add more later under the cover of darkness. I had an idiot inspector make me put rubber grommets around the bare copper grounds out of the service panel, one that went to Earth, the other into the rebar of the foundation. When I inquired why he said if they are inside a metal screw connector they could shear off in a earthquake. I told him the metal building was rated for 100 MPH winds and an earthquake that would shear that wire off would bring the building down, destroy the cities infrastructure and kill thousands of people. Anyway, if you get everything permitted, be patient and best of luck. Cali is way over kill on regulations, doing it to NEC code many times isn't good enough.
 
Where are you at in Cali? I wired my own two shops I had there and a couple small shops for friends. I was in Riverside county the inspectors there were a complete joke. I would keep as much as you can on the down low. If it is a new shop get the basics permitted and bought off and add more later under the cover of darkness. I had an idiot inspector make me put rubber grommets around the bare copper grounds out of the service panel, one that went to Earth, the other into the rebar of the foundation. When I inquired why he said if they are inside a metal screw connector they could shear off in a earthquake. I told him the metal building was rated for 100 MPH winds and an earthquake that would shear that wire off would bring the building down, destroy the cities infrastructure and kill thousands of people. Anyway, if you get everything permitted, be patient and best of luck. Cali is way over kill on regulations, doing it to NEC code many times isn't good enough.


100% on the down low. Do the absolute minimum you need to, then make it the way you want later. Don't even get me started on the Green tag scam.
 








 
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