Multiple outlets on a 240V circuit

[conmgt]

I have a 3ph panel from which I have to power 3 1ph machines, a mill, a lathe, and a fan. They are 9A, 7A, and 8A respectively and here's what I think my options are, check my sanity and tell me what you think:

(9Ax1.25)+8+7=26.25A

A 30A 2W circuit with #10 feeders and #14 taps to 30A recpts, put 30A plugs on the equipment in place of their 15A plugs. Any violation?

A 30A 2w circuit with #10 feeders and #14 taps to 15A recpts protected by some sort of ocp. I've seen jbox plates with a switch and a fuse but that's 120V only. Any products out there short of a full size disconnect?

A 20A 3w circuit with #12 feeders and #14 taps to 15A recpts. (9Ax1.25)+8=19.25A

A 30A 2W feeder to a subpanel near the machines with 15A breakers to feed machines. More $

3 separate 15A circuits. This will create conduit/box/panel fill issues that can only be resolve with more conduit and a subpanel at the main...not an option, $$$$

Thanks.

 

[infinity]

I would run 2-20 amp circuits. The largest machine on one circuit, the other two on the second circuit. Do you only have one slot in the panel?

 

[conmgt]

I have one 3/4" EMT feeding this room and it needs to feed the machines, lights, and general recpts. Lights are on their own circuit, recpts on 2 more...that's 6 wires...room for 3 more. Could MWBC the recpts and even add the lights to knock it down to 4 wires. Room for 5 now.

Partly want to expand my experience with feeding multiple loads on one circuit...practice makes perfect.

 

[Rick Christopherson]

I don't know what will be the most cost effective for your situation, that's for you to determine with more information. However, from the title of your question alone, I would consider a 4-wire MWBC with #14 at 15A and leave the existing 15 A plugs on the tools.

Also (and I am not a code expert, so don't take this as advice), but none of these loads constitutes a continuous load (and except for the fan, they hardly ever pull FLA), so to the best of my knowledge, you do not have to consider the 80% derating on a multi-outlet (single-phase) circuit. If these loads will never run simultaneously (which is common if this is a home workshop) then you could actually wire all three of these to a single 20 amp circuit with either 15 or 20 amp outlets.

 

[david luchini]

A 30A 2W circuit with #10 feeders and #14 taps to 30A recpts, put 30A plugs on the equipment in place of their 15A plugs. Any violation?

I believe this would be a violation of 210.20(B) (& 210.19(A)(4))

A 30A 2w circuit with #10 feeders and #14 taps to 15A recpts protected by some sort of ocp. I've seen jbox plates with a switch and a fuse but that's 120V only. Any products out there short of a full size disconnect?

Same violation.

A 20A 3w circuit with #12 feeders and #14 taps to 15A recpts. (9Ax1.25)+8=19.25A

Same violation.

 

[augie47]

You have to make sure your equipment is properly protected per Art 409 or Art 430. It is doubtful you can do that with only the 30 amp OCP device.
You could follow the 240.21 tap rules and use a 30 amp feeder to supply OCP devices for each piece of equipment. I don't care for the idea, but it would be Code compliant to install fuses at your taps and feed receptacles. IMO, a 2 pole fusible disconnect would be the better plan.

 

[conmgt]

If these loads will never run simultaneously (which is common if this is a home workshop) then you could actually wire all three of these to a single 20 amp circuit with either 15 or 20 amp outlets.

Not a home shop but a business with employees.

 

[conmgt]

I would consider a 4-wire MWBC with #14 at 15A and leave the existing 15 A plugs on the tools. .

By 4 wire, do you mean ABCN? If so, these are 240V, no N.

 

[infinity]

By 4 wire, do you mean ABCN? If so, these are 240V, no N.

I think that you left that part out in your previous posts.

 

[sameguy]

Run #6 or #4 if no neut. subpan. then refeed your loads.

 

[conmgt]

Run #6 or #4 if no neut. subpan. then refeed your loads.

Can't put 3 #4 in a 3/4 EMT. A subpanel is ideal and my first choice but time and $$$.

I'm going with 3 #12 from the panel to 3 20A recpts. Machine 1 on AB, Machine 2 on BC, Machine 3 on CA. Might go up to #10 to combat VD.

 

[infinity]

I'm going with 3 #12 from the panel to 3 20A recpts. Machine 1 on AB, Machine 2 on BC, Machine 3 on CA. Might go up to #10 to combat VD.

How will this work with only three conductors? And what size OCPD are you planning on using with 20 amp devices?

 

[conmgt]

How will this work with only three conductors? And what size OCPD are you planning on using with 20 amp devices?

Well, please correct if I'm wrong, the loads are all 2w 240V. The #12 will be on a 3pole 20A OCPD. This is a 3ph service.

 

[sameguy]

compact conductors you can

 

[S'mise]

I believe this would be a violation of 210.20(B) (& 210.19(A)(4))

Same violation.

Same violation.

I agree

I know It complies with 210.21, but I prefer to size receptacles (wire)to their full rating, so some bozo does not plug a 30amp load into a source of only 20a.