Getting Creative with 220V Contactors/Extensions -- Am I good to go?

[Ryan Kaylumbs]

Some recent discussions regarding electrical has got me thinking about the setup I put together to power my jointer and dust collector on a 30 amp – 220v dryer outlet. This setup is only plugged in when I’m woodworking and then unplugged after use. For the most part it’s just running my dust collector at 7amps. Both tools running together pulls like 17 amps on a 30 amp circuit.

What do you guys think? Good to go or any glaring issues? Thanks!!

[John K Jordan]

Ryan,

I am NOT an electrician but an amateur who usually wires his own stuff. Several things about your connections bother me. Let me make sure I understand:

You have a 30 amp breaker feeding a 30 amp outlet in the wall.
An appliance cord of unknown wire size (10ga?) from that outlet feeds:
- what looks like a 50 amp receptacle for the welder that could draw 42 amps but you only run it at 28 amps.
- a 12 gauge cord to a jointer
- a plug with an unknown sized flexible cord to a contactor which feeds a 16 gauge extension cord to a DC.

Assuming what I see this is correct:

I don't know what you can get away with when you plug an appliance cord into a wall outlet according to code. I don't know if code even applies to anything plugged into a receptacle. I wonder about a few things that could go wrong before the 30 amp breaker trips.
1) Someone uses the welder in stick mode and the 48 amps melts the appliance cord and burns down the shop.
2) Someone plugs in some other device into the 50 amp receptacle and melts the appliance cord and burns down the shop.
3) The jointer shorts out and melts the 12 gauge extension cord and burns down the shop.
4) The DC shorts or overloads and melts the 16 gauge extension cord and burns down the shop.

You don't show the plug from the 220v contactor or socket on the DC extension cord but it looks much like a 110v extension cord. If this is so it seems like a No-No to me. If someone plugs a 110v tool or device into the socket from the contactor and puts voltage on the common wire as well as the hot wire this could happen:
1) the tool or device is destroyed
2) if the tool or device is not double insulated or shorted the person gets shocked or dies from electrocution.

I may not understand all of how you wired this and my comments might be a little over dramatic but I'm trying to imagine the worst case. One danger of mismatched receptacles, wires, and 220v o a 110v socket is someone who doesn't understand the limitations may plug in something inappropriate. Maybe it's a mistake you make. perhaps a friend or relative using the shop when you are not there; maybe the guy who buys the house someday.

In my own shop had a similar situation where I wanted to feed several circuits in my DC closet from one breaker in my main panel. I ran #6 copper from the main panel to the far end of the shop. There, it feeds a sub-panel with smaller breakers, contactor, and receptacles, both 110v and 220v. That way the breakers in the sub panel should catch any downstream problems in the motors or wiring.

Maybe an electrician or three will chime in with their professional thoughts.

JKJ

[Peter Christensen]

I'm no wire tugger and for the most part agree with John.

When I needed to put smaller machines on a circuit like you did in the last place I lived in I bought a small panel box and wired it so I could run the smaller machines and still protect them. It is likely not going to meet code but it's better than what you did. I wouldn't try to make 110V circuits in there too but it probably could be done by someone that knows what the are doing.

[Bill Dufour]

Please note my comments below only apply in the USA. I have no idea what code your country follows. If you are in Europe each plug will have an included fuse so your method should be okay as long as you upsize the wire to match the breakers.

I did similar to Peter. I had an old breaker box so I even supplied the 30 amp outlet from another breaker in series. Then several 240 circuits and some 120 as well since I had a neutral at the outlet. You do not have a neutral so no 120 for you. Your secondary wire sizes are much too small for the 30 amp breaker. #12 is max 20 amps. You need to run #10 or better for 30 amp.
Check craigs list for used breaker boxes with breakers installed and for wire. Technically you have to use a 30 amp outlet if it is supplied by a 30 amp breaker. but I have run 120 outlets on 30 amp breakers but only I use those outlets. They are only one outlet on the front of a big 240 machine. Not used much if at all.

I did run my welder on the dryer outlet and it worked well at 1/2 power or so. A 50 amp stick welder outlet code only requires 40 amp service wire/breaker because it is not rated as 100% time. NEC calls it something like 50% duty cycle. Mig or Tig code requires the full amps for the outlet.
Bill D

[John Park007]

"All" the wires must be able to carry the breaker amperage or your asking for a fire. ..... no exceptions.

Another thing to think about is the tool you using , sure you always want to plug it into a circuit that has enough protection but what if you over loaded you vacuum, the breaker will not trip and the motor will burn. This is what will happen in your current set up .
First get the wires right then perhaps think about putting breakers on your individual machines. Newer machines have breakers built in, but seems like your handy that way so think about it .

[Ryan Kaylumbs]

Thank you guys! I really appreciate the phenomenal input.

I really like what you did which that breaker box Peter. I think I will emulate that.

What I'm thinking about doing is the following. Let me know if you think I should reorder anything.

- 10g Appliance Cord to 220V 30-amp contactor switch input
- 10g cord from 30amp contactor out to 6-50R External Outlet (So I can use my welder on the 30amp breaker)
- Then 10g cord with a 6-50R plug end going into a breaker box (Essentially the Breaker Box plugs into the 6-50R outlet)
- Two 15amp 2-pole breakers in the breaker box
- 12g wire out of breakers to two 15amp 220v outlets (one for dust collector, one for jointer)
- 12g cord wired straight into the motors running 15'-20' to outlets that are on 15 amp breakers.

I like the idea of the contactor switch feeding power to everything so that when the switch is off the entire system is de-energized. Should I change the order of this? I was going to put the remote switch that controls the contactor on an outlet that powers my overhead lighting so that when I leave the garage and turn off the lights the switch turns off and the everything is de-energized incase I leave it plugged in.

I want to continue to use the 6-50R surface mount outlet so I can run my welder and have it directly on the 30amp breaker (everything here will be 10g). Once I hit the breaker box with the 15amp breakers the wiring drops down to 12g throughout the hole system. I thought about having a 30amp breaker in the box with 10g wire down to the 6

The tools draw 7.5amps and 10amps respectively and will be on their own 15amp breaker wired with 12g.

Here's teh box I was going to get: https://www.homedepot.com/p/Square-D...0SCP/100190554
And the breakers: https://www.homedepot.com/p/Square-D...15CP/202353317
These outlets: https://www.homedepot.com/p/Leviton-...29-W/301207438

Do i need to use solid wire between the breaker and the outlets or can I use the SJOOW cable I've been using.



Thanks guys, I really appreciate all teh help.