Wiring Question

[Mmfh]

Hey there,

I'm wanting to save on some wire if I can. I have two machines I want to power on the opposite side of the garage from the service panel. About 50' run of wire.

These two machines are next to each other and one is 220v and the other is 110v. 220v machine FLA is 15 amps, 110v machine FLA is 8 amps.

Can I come off the service panel with a 30 amp double pole breaker and run it over to the 220v machine, come off one leg of the 220v and the neutral and take 110v to the machine next to it?? Is that electrically safe?

I would be pulling more amps from one side of the double pole than from the other. If I'm under rating for the breaker it should work fine, right? Keeping in mind that I'm a one man shop and can only run one machine at a time.

I've seen machines where 220v was run to the machine for a motor, then inside the machine power was taken from one leg and used to power a 110v motor inside the same machine. So, to me its basically the same thing.

Can I run the two different machines off of the one 220v circuit? I know I can but would it be smart to do it or not?

Thanks very much,

Mm

 

[pattenp]

I don't know of a code reason why you can't do it. Even if both machines are running the worst thing to happen is the breaker may trip but I doubt that will happen.

Edit: I just bought some 10/3 and got it from my local electrical supply house for $0.79 a foot compared to $1.66 a foot for 50' roll at Lowes

 

[Mmfh]

That's what I figured, if I size the breaker and wire right, everything should be good and I can save a little time and money running another circuit for the 110v machine.

Thanks

 

[aandpdan]

You've got a problem code wise.

You can't use the 30 amp breaker. Putting a 15 or 20 amp receptacle on such a circuit is a violation of NEC 210.21.

But, using the 10/3 you bought you could put a small subpanel near the two machines, on a 30 amp feeder, and then put in a 20 amp 240 volt circuit and another 15 or 20 amp 120 volt circuit.

 

[Mmfh]

Is that basically the same thing except using a small panel next to the machines? Small panel has a double pole 20 amp, also a 15 amp single pole breaker? Is that right?

 

[Mmfh]

I don't know of a code reason why you can't do it. Even if both machines are running the worst thing to happen is the breaker may trip but I doubt that will happen.

Edit: I just bought some 10/3 and got it from my local electrical supply house for $0.79 a foot compared to $1.66 a foot for 50' roll at Lowes

I haven't checked anywhere except the Depot and Lowes for wire prices and panels. That is something I will do, check out probably Platt electric next.

Thanks

 

[pattenp]

Good catch and correct. That didn't even dawn on me.

You've got a problem code wise.

You can't use the 30 amp breaker. Putting a 15 or 20 amp receptacle on such a circuit is a violation of NEC 210.21.

But, using the 10/3 you bought you could put a small subpanel near the two machines, on a 30 amp feeder, and then put in a 20 amp 240 volt circuit and another 15 or 20 amp 120 volt circuit.

 

[kenfath]

"But, using the 10/3 you bought you could put a small subpanel near the two machines, on a 30 amp feeder, and then put in a 20 amp 240 volt circuit and another 15 or 20 amp 120 volt circuit."

Will the "small subpanel" require a ground rod?

 

[pattenp]

That is right. It is a sub-panel. Cost wise it may be a toss up to doing the two circuits vs the sub-panel.

Is that basically the same thing except using a small panel next to the machines? Small panel has a double pole 20 amp, also a 15 amp single pole breaker? Is that right?

 

[pattenp]

Not if the sub-panel is in the same building as the main service panel.

"But, using the 10/3 you bought you could put a small subpanel near the two machines, on a 30 amp feeder, and then put in a 20 amp 240 volt circuit and another 15 or 20 amp 120 volt circuit."

Will the "small subpanel" require a ground rod?

 

[Charles (in GA)]

Assuming you have 10/3 with ground then you will have the four wires you need to power a subpanel. Get a four space one or no more than 6 space probably, and install the necessary breakers for each device and run wire and receptacles to each one. Easy. Small panel is only $20-$30 at the most.

These small panels almost never come with a ground bar. They have a insulated from the case neutral, but no ground usually, so open it up and look carefully. If you need a ground bar, they should be hanging on the rack right there by the panels. There should be predrilled holes in the back of the panel that the holes in the ground bar will line up with, and you can easily screw the ground bar down, without any need for drilling. Be sure and use the same brand panel, ground bar, and breakers.... preferably the same as the other panel in the building for ease of swapping breakers around in the future.

Charles

 

[brewchief]

Is it going to be cheaper to do a subpanel that you need an extra breaker, heavier wire and the panel itself or just run two 50' runs of 12 wire and be done with it? Time wise two separate runs that short should be done far before you could run one feed to a sub and wire it and the receptacles for the machines.

 

[Mmfh]

As it turns out its going to be cheaper to just make the two runs to the machines and be done with it. At least as far as the Depot prices are, wire is cheaper than panel and breakers.

I'm going to check the big electrical outfit tomorrow, but that's most likely the way I'm going to go.

Thanks very much for entertaining my idea.

Mm

 

[SiGmA_X]

Mmfh - The only additional consideration I would make is will you potentially want to add another machine, receptical, etc over by the new run. If so, you may want to run the 10/3 or 8/3 even, and put a subpanel in. Otherwise, hit up Platt for some 12/3 and some 14/2 and call it a day.