3 phase riddle - home workshop 3ph wiring

[86turbodsl]

Buy a new Baldor. $1,000 +/-

If you old motor is in decent shape, you should get about $500 for it.

Nah, the market for used 3ph motors isn't that good around here. We're super depressed in Michigan. Nobody has any cash.

cheaper to stick with what i have for now.

 

[Strouty]

I agree, I have never seen a used three phase motor sell for much. The people who need three phase motors buy new, the guys like us buy used and usually at scrap prices. I pay no more than 50 cents a pound for 3 phase motors.

 

[wyliesdiesels]

Steve,

There's a story here. Dad worked for the power company as an engineer. He got me an internship when i was in college for engineering. I ended up doing engineering special projects in the area. Fast forward almost 15 years, i started building the house we're in now. Called for service, and the engineer showing up knew me. Knew my dad, etc. It was like a reunion. I told her i was running "big motors" out in the shop. She smiled, said ok, we go on with life, service gets installed. Finish building the house, and one day a service truck shows up. Yanks the 10KVA transformer off the pole and puts in a 50kva. It's a giant can hanging off the pole. I'm the only guy on it. I'm good. It pays to have connections. And i have 400A service to the house. 200A to the shop.

The compressor is the big load. For now. I have thought about home businesses though and one thought was a 15HP CNC mill. So i'm a little oversized. Maybe.

The original question wasn't about homemade buss bars, it was about running wire around the outside of the shop used "AS" a buss bar. It was more the idea. Not planning any copper bars. THHN in conduit.

Keep in mind 50Kva will give u around 200a continous!

 

[86turbodsl]

I agree, I have never seen a used three phase motor sell for much. The people who need three phase motors buy new, the guys like us buy used and usually at scrap prices. I pay no more than 50 cents a pound for 3 phase motors.

<looking around for the damn "like" button....>

 

[InterpreDemon]

I threw a skid load of 3-10hp 3ph motors in the dumpster last Fall... nice old American iron I picked up free from various industrial jobs and that I kept around for years thinking they would be good for something, like induction wind turbines and such. Lately I have decided I do not need my widow to have to deal with these things someday and have begun distilling the "inventory" to projects I might actually be able to get to in my remaining years. It's amazing the items and projects you discover that you forgot about over decades, like a spanking new ball-screw set for my Bridgeport... now I just have to remember why I never got around to installing them.

 

[86turbodsl]

Interpre..

If you decide to bin the ball screws, give me a heads up, and i'll have a bin delivered to the jobsite for you to "dispose" of them in.

Shame about the motors. I have a couple projects that need 3ph motors right now.

 

[Strouty]

Around here, I can find three phase motors all the time. I buy them at the scrap yard for 50 cents a pound. These are motors that get removed from large facilities in the area, they never see the outside and some are like new. The guy will let me buy and try them, if there is an issue, I can return them until I get one I like. I have bought 4 or 5 and they all worked very well.

 

[930dreamer]

I have two pallets of them also, O yah I'll use them all.

 

[86turbodsl]

Update on this compressor info: I looked at the pulleys. Motor is 10hp 1725rpm, 9" pulley. The pump pulley is 19". I think that makes my rpms about 850. I can drop power input requirements to about 8HP at 125psi. I can drop it another couple by dropping pump rpm to about 600. I would drop down to about 30cfm though. I will have to look at my sandblasting requirements to see if that's doable. I run dad's 6.5HP 2stage compressor right out of air when blasting now.

 

[My Old Tools]

I'm doing just about the same thing on a little smaller scale. My RPC is just 10HP. I have a 6 space 3 phase panel. I ran a 30 amp circuit around the shop with twist lock receptacles every 6 feet or so. That takes care of most equipment. I have a couple of dedicated circuits, but like you, I work alone, so the 30 amp is adequate for just about everything I run. My equipment all have low voltage controls with overloads, so no disconnects.

 

[A_Pmech]

Don't over-think this! You have 50kVA on the pole and a suitable phase converter. Wire those ******* up and flip the switch to "auto!"

 

[bimmer1980]

86Turbo-- Where are you at with your wiring? I'm curious to see some pictures of what you ended up doing....

 

[86turbodsl]

I haven't run anything yet. My missus is on me hard to get the lean-to done on the shop so she can get the baler out of her barn. That's my focus for now. I'll get back to the shop restoration after that is out of the way.

 

[930dreamer]

I picked up my 30hp idler for $85.

 

[sberry]

Run another panel to the other side of the building so it can be piped sideways to some machines grouped the best they can be.
I am on single but actually ran 5 sub panels. I have a large shop, you could do 1 extra on the far wall and to me its as easy add another if I got to go over doors with multiple circuits. I piped in the floor but you may need to go overhead but a sub takes care of a lot of issues in one sweep. Gives a set of conductors on that panel for a welder outlet if needed and saves a ton of branch and disconnect, also saves queer busway parts etc and makes it all standard.
Breaker wire to plug. Leave plenty of cord on the machines to start with. Stuff you rarely used could be plugged until you get your feet wet and adding another pipe out the side of the box as needed is easy and you don't end up with extra from visions you dreamed up along the way. A recept might share 3 machines, 1 you use 90% of the time.
This would save a lot of motor sizing requirements that may be allowable but more complicated than needed especially where with a sub secondary wiring becomes relatively short, if you go sideways on some its all at ground level.

 

[rockwithjason]

you know what the problem with having lots of machines is? it costs a lot to wire them. The bus idea would work but you will have to have fused disconnects at every load sized for the tap. you will have to follow the tap rules in the code that are appropriate for the individual taps. You will also likely have to wire the buss heavy to meet ampacity requirements. You will have to have a disconnect and an OCPD at the head end of the bus also. No matter how you cut it this won't be cheap. You will likely have to run conduit and LARGE jboxes to accommodate the taps also. exposed romex won't cut it, at least if you want to be legal.

 

[sberry]

Buy 2 x the pipe you need to start with and extra boxes. Have and end up with enough stuff on the shelf its not an impediment to installing a piece as needed. Every machine needs a plug, keep an extra in stock so there isn't the impu8lse to modify a machine cause you don't have one.
Jason elaborated some, I simplify it by not having to wire them all but provide access to a couple recepts.

 

[bloomingtonmike]

I am doing two 1ph panels (one on south wall and one on north wall). South wall will feed a 20hp rpc (have caps and 30hp baldor to upgrade it). That rpc will feed two main lug only 3ph panels - one on south wall and one on north wall. Putting panels on wall surface but have in wall wiring as well. Panels ge powermark and are nib $100 off ebay.

Woodworking on south wall, cnc mill and metal lathes north west, cnc router north east.

Shop is 40x64x16

 

[86turbodsl]

Mike, sounds like the same shop. You have any pics online?

 

[Alchymist]

Ok, electrical gurus.

Then to save some money on wiring, i would run a "buss" of 10ga three phase around the perimeter of the shop, to run additional loads which are point of use, and would typically be the only load being used by a person at any one time, such as a 5hp radial saw, or a 5hp table saw, or jointer, or whatever.

Each machine would be connected to the buss with it's own fused disconnect to protect that machine from overload. There would also be a breaker protecting the buss lines at the capacity of that line to prevent meltdown. Thoughts?

Might it be possible to run your original "buss" wire but drop it into a sub panel, come out of the sub panel on feed thru or separate breaker to another sub panel, then wire individual loads to each panel? Shouldn't take much more wire, and if you jump to 8 gauge wire you have the option of running perhaps 2 machines at once, since you never know if it might become a requirement in the future.

 

[bloomingtonmike]

Mike, sounds like the same shop. You have any pics online?

http://www.garagejournal.com/forum/showthread.php?t=256669&page=5

I just ran the wire up and over for the 2nd 3ph panel (2-2-2-4). This is the second 2-2-2-4 run I have done as the 1ph panels also have one. I also ran the wires for the electric boiler (three runs of 8/2 and a 12/2) to a location over by the radiant floor heat manifold. I have not built my panel yet for that.

The 20hp rpc is fed off the 200amp main 1ph south wall panel. I feed the first 3ph panel on the south wall from the 20hp rpc. I will then connect the up-and-over 2-2-2-4 to a 3ph CB in that first 3ph panel and feed the main lugs on the north wall 2nd 3ph panel with the 2-2-2-4.

Cost was $100 ea for the main lug panels shipped and I bought the wire at Menards to connect them up at $1.69 a ft.

I plan to flip the 1ph breaker on. That will start the RPC. Then I plan to flip on the breaker that I need that feeds each tool. Each tool will have its own disconnect and mag starter. If I need to use a tool on the north wall I will energize that panel and then turn on that circuit at the north wall.

Current 3ph tools include a 3ph 5hp dust collector (currently on 7.5hp RPC), 12" jointer (currently on VFD), T1002S sliding table tilting spindle shaper (currently on VFD), a CNC 1050 Knee Mill (on VFD), and CNC router on VFD. This design is in anticipation of a Wide Belt Sander purchase and a CNC lathe eventually.

 

[wyliesdiesels]

Remember #2 AL MHF has a max ampacity of 90a in your application.