2 or 3 wire for 220

[projectnut]

In many areas codes are changing. We had a remodeling project a couple years ago which included installing a new range. The old receptacle was 12-2 wire with 2 hot and a neutral. The new code required 12-3 with 2 hot, 1 neutral, and 1 ground. Fortunately when the house was built the contractor included a 12-3 wire feed to the receptacle.

When I added circuits in the shop to power 220V equipment I used the 12-3 wire feed. The difference in cost was minimal. In our area a 250 roll of 12-3 wire costs about $108.00 from Home Depot. A roll of 12-2 wire is about $60.00. For a little less than $50.00 you can be ahead of any code changes.

 

[springer]

hey @springer,
glad to hear you are moved! i hope it was easy

Q1:
you'll need 2 hot 240 volt wires and a ground to power up the VFD, a neutral wire is not necessary - there is no place on the vfd to wire it to

Q2:
i would run the 240v single phase to a distribution box (load center), then split into 120v circuits from the load center
from the load center you can wire the outlets and machines

Thanks Ulma, I don't know why it never crossed my mind to run a distribution box. That makes the most sense. Then I can run a few plugs to give me more options in the future.

I might give you a call when I'm ready to wire up the motor and stuff on that mill. It's still in pieces right now tho. I got a little carried away after I took it apart to unload it. Turned into a full cleaning and restoration project instead of a simple take apart and put back together haha.

 

[springer]

To clarify, their is no neutral in the US for using a 220V VFD, but you will often see a "N" terminal on the VFD. Do not hook this up to neutral, wire per the directions. Breakers protect the wire, there is some variations on sizing specs. of breakers relative to the a multitude of NEC codes, etc. Although it is not common to bring a neutral wire to a machine which is 220VAC, you can do it and then breakout separate sub circuits at the machine enclosure using supplemental breakers or fuses. Just remember that all the wire up to the fuse/breaker should be rated for power in breaker size (in this case 30A). On both my mill and lathe I use 4 wire cable (L1, L2, N, G), these then connect to the power disconnect switch at the machine and then to breaker/fusing if used. VFD's do provide guidance's on VFD fusing/breakers for each model, in general a 30A breaker is sufficient for either a 2 or 3 Hp single phase 220VAC VFD.

Example below, supplemental dual pole15A breakers for power supplies, second dual pole15A breaker for sockets mounted at the lathe and for DRO, and fusing for the VFD. The lathe is setup for either single or 3 phase 230VAC, but currently it is powered off of single phase. Attached enclosure diagrams give some suggestions, you need to comply with all electrical codes.

View attachment 327877

Thanks for the info mark, I always look forward to reading your posts. I have a lot of your diagrams and advice saved for when I start wiring my vfd.

 

[Ulma Doctor]

Thanks Ulma, I don't know why it never crossed my mind to run a distribution box. That makes the most sense. Then I can run a few plugs to give me more options in the future.

I might give you a call when I'm ready to wire up the motor and stuff on that mill. It's still in pieces right now tho. I got a little carried away after I took it apart to unload it. Turned into a full cleaning and restoration project instead of a simple take apart and put back together haha.

Cool brother, call me if i can help!

 

[ThinWoodsman]

When I added circuits in the shop to power 220V equipment I used the 12-3 wire feed.

How far are you running the 12? I was looking at adding a 30-amp 220V line across the basement, and getting towards 50-60 feet with the drops and all, I was worried that 12 wouldn't cut it. Not an electrician, so I just go by the tables in the Ugly's guide.

 

[HMiller]

I've been toying with the idea of a few 50 Amp outlets scattered around near where I might put machines in the future. Then if I want something I'll put a plug on a subpanel and add the breakers I need. A little more expensive now, but the plug makes it not subject to inspection or permits. Then if I get a mill or shaper it is quick to give it whatever power it wants.

This of course requires 4 wire (3 plus ground), but it saves pulling new wire in closed walls.

If it is a bad idea for some reason let me know...

 

[mksj]

Not an electrician, but for running 30A wire from your panel to a socket the minimum would be 10AWG copper. Lots of sources as to types of wire, fill ratio if in conduit, etc. If you are running a motor or VFD with higher peak draws there are formulas for up-sizing the breaker or changing the breaker trip rating curve. If one was to run 50A sockets, then all the wire and sockets would need to be rated at 50A unless you had additional breakers/fusing for the smaller wire/socket size. It is also dependent on the type of breaker that one can use for branch circuits vs. in a machine electrical cabinet.

Typically I run a sub-panel in my garage and breakout dedicated lines each on a separate breaker, and or a cluster of sockets with different ratings and each on their own breaker. It does not stop you from using the same line/breaker for additional sockets at different locations. A bit different with extension cords, but for 30A I use a minimum of 10AWG for extension cords, typically generator cords since I use 4 wire.

What Size Wire for My Breaker Do I Need?

Whether your breaker is a 30 or 40 amp, wire size is crucial for performance. Here’s how to determine what size wire you need.

www.totalhomesupply.com

My current house I have two 200A panels on either side of my garage. Below is one cluster of two 30A 240VAC 4 wire, one 20A 240VAC 3 wire, one 20A 120VAC GFI setup for machines, I have the same repeated on the other side of my garage except I have a 50A 3 wire socket instead of the two 30A. All on separate breakers, I also have a string of 20A 120VAC sockets around the garage and sockets on supplemental breakers at my mill and lathe since they are in the middle of the garage.

Previous house had a similar setup, with a 100A sub-panel on the other side and had various socket clusters on 3 walls. If you are using the sub-panel at 100A then you need 3-3-3-5AWG copper wire 75C via conduit with the adequate fill volume, I pulled separate stranded THHN 90C wires mine was in 1.5" electrical PVC conduit about 35' from my main panel. I am limited to the the temperature rating of the sub panel which was 75C. Gauge also depends on the material/type of wire and distance. General guidance on conduit fill volume, I always go a bit bigger than minimum to make pulling the wires easier.

Elliott Electric Supply - Lower Cost, Quality Electrical Supplies, and Personal Service

Electrical Supplies Distributor. Elliott Electric Supply is your local electric supply house. We Deliver Lower Cost, Quality Products, and Personal Service

www.elliottelectric.com

Elliott Electric Supply - Lower Cost, Quality Electrical Supplies, and Personal Service

Electrical Supplies Distributor. Elliott Electric Supply is your local electric supply house. We Deliver Lower Cost, Quality Products, and Personal Service

www.elliottelectric.com