220V question

[John K Jordan]

If I run the welder then I don't run any other tool at the same time.

Your comment made me think of my own little weld shop. I have three welding machines (tig, mig, stick) and a plasma cutter that all use the huge NEMA 6-50 plugs -- one 50 amp breaker feeds receptacles in two rooms and outside. I can't possibly use more than one at a time but imagine if I had a class.

JKJ

[Charles Lent]

Just remember, the circuit breaker must be sized so as to protect the wire that it supplies. Don't hook a 10, 12 or 14 gauge wire directly up to a 50 amp circuit breaker. Provide smaller circuit breakers for each size wire. Supply 10 gauge wire from a 30 amp circuit breaker, 12 gauge wire from a 20 amp circuit breaker, and 14 gauge wire from a 15 amp circuit breaker. Don't connect these smaller wires directly to a 50 amp circuit breaker. Also, use plugs and outlets that are the same rating as the wire and circuit breaker that feeds it. Determine your wire and circuit breaker size based on the maximum current rating of the tool that it will feed, and don't use wire smaller than 14 gauge in an electrical power distribution system. If the wire distance between the circuit breaker and the tool will be more than 200 ft and the tool will be drawing more than 80% of the circuit breaker rating continuously, it would be a good idea to increase the wire size (lower the gauge rating) by one size, but do not increase the breaker size (this is to reduce the voltage drop in the long wires). The electrical code allows higher ampere ratings certain uses and types of wire, but my information supplied here is a good general use guide for home shop wiring that should avoid major installation mistakes made by many DIYers. Whenever in doubt about what you are doing, call an electrician. Don't burn your shop down.

Charley

[Mike Henderson]

I agree with Charles. Put in a subpanel. They're not that expensive and you can wire it yourself if you have some experience with electrical wiring. If not, hire an electrician. That will give you a lot more flexibility.

When I replied above, I was referring to the 50 amp line that I have coming into the subpanel in my shop.

Mike

[John K Jordan]

...If the wire distance between the circuit breaker and the tool will be more than 200 ft and the tool will be drawing more than 80% of the circuit breaker rating continuously, it would be a good idea to increase the wire size (lower the gauge rating) by one size, but do not increase the breaker size (this is to reduce the voltage drop in the long wires).

There are on-line calculators that will tell you the exact wire size needed for a given voltage drop, no guessing. I used one when I ran wire in conduit 250' underground for a 100 amp service in my shop. I didn't want any issues when big motors started.

JKJ

[Bill Dufour]

Stick Welders are special by electrical code. I do not think it applies to mig, tig welders but for stick a 50 amp outlet only has to be wired and breaker sized for 40 amps. They figure a stick welder can only run something like 50% of the time so the wires will have off time to cool down. That said I used 50 amp wire since I got a short. cut off cheaper then 40 amp cut to length. I only needed like 4 feet anyway.
Craigs list can be a good source of heavy wire. I used 150/ amp wire to supply 70 amps to my shop because it was cheaper from Craigs list then the lighter wire would have been at the big box store.
I recommend buying the same brand and model of your existing breaker panel so you can swap breakers around.
Bill

[Bill Dufour]

There are on-line calculators that will tell you the exact wire size needed for a given voltage drop, no guessing. I used one when I ran wire in conduit 250' underground for a 100 amp service in my shop. I didn't want any issues when big motors started.

be careful how the calculate the wire run. the professional ones ask you to double the measured distance since they calculate distance to and from the user. Some of the homeowner ones online do it the other way and only measure one way distance.

JKJ

be careful how the calculate the wire run. the professional ones ask you to double the measured distance since they calculate distance to and from the user. Some of the homeowner ones online do it the other way and only measure one way distance.

[John K Jordan]

be careful how the calculate the wire run. the professional ones ask you to double the measured distance since they calculate distance to and from the user. Some of the homeowner ones online do it the other way and only measure one way distance.

You are correct. Most of the calculators spell this out if you read. Some of them don't consider how the wire is run - cable, direct burial, in air, etc.

I calculated multiple ways, compared to tables, talked to a couple of electrical people, then bumped up a couple of wire sizes. It is so much effort to dig a trench and lay wire and conduit (did it all myself) that I wanted to err on the far side. The wire is big enough to even easily handle a much higher amperage than my shop box with an acceptable voltage drop. Big copper is expensive but compared to the effort and total material cost of the entire job I saw no reason to scrimp.

BTW, I put two extra conduit runs in the trench - one with some ethernet lines for WiFi and a big one with nothing inside but a rope. You never know!

JKJ

[lee cox]

I ran 6ga wire for my 50 amp welding circuit. The price for 6ga and 8ga was not much different. Also my welding manual for my welder states I need to have an 8ga ground. The ground wire size for 8ga was 10ga. So I went with 6ga wire.

[Curt Harms]

I would think you should start the dc first because it will take longer to get up to speed and be drawing more amps until it reaches full rpm. Of course the tablesaw motor is bigger and draws more amps so it makes sense to start the most amp motor first.
If all else fails switch to three phase equipment and use vfds with a slow acceleration setting .
Bill

I'd agree with Bill. A dust collector impeller is a lot heavier than a table saw blade so more weight to get up to speed. The table saw may draw more amps once running depending on what it's cutting and how fast.

[Rollie Meyers]

With motors & HVAC equipment the NEC allows wire & fuse/circuit breaker combinations that are not allowed for normal branch circuits if certain criteria is met, when a motor has overload protection, the fuse/circuit breaker is just providing short circuit protection, & 12 AWG wire on 40A breaker would be not be unheard of under the right circumstances.

[Tony Connaghan]

Just remember, the circuit breaker must be sized so as to protect the wire that it supplies. Don't hook a 10, 12 or 14 gauge wire directly up to a 50 amp circuit breaker. Provide smaller circuit breakers for each size wire. Supply 10 gauge wire from a 30 amp circuit breaker, 12 gauge wire from a 20 amp circuit breaker, and 14 gauge wire from a 15 amp circuit breaker. Don't connect these smaller wires directly to a 50 amp circuit breaker. Also, use plugs and outlets that are the same rating as the wire and circuit breaker that feeds it. Determine your wire and circuit breaker size based on the maximum current rating of the tool that it will feed, and don't use wire smaller than 14 gauge in an electrical power distribution system. If the wire distance between the circuit breaker and the tool will be more than 200 ft and the tool will be drawing more than 80% of the circuit breaker rating continuously, it would be a good idea to increase the wire size (lower the gauge rating) by one size, but do not increase the breaker size (this is to reduce the voltage drop in the long wires). The electrical code allows higher ampere ratings certain uses and types of wire, but my information supplied here is a good general use guide for home shop wiring that should avoid major installation mistakes made by many DIYers. Whenever in doubt about what you are doing, call an electrician. Don't burn your shop down.

Charley

I have a woodmaster 5hp planner that I want to hook up to a 30amp breaker, could I get by using 8-3 instead of the 10-3? I have about a 20ft. run from the main panel and would like to use up the 8-3 that I already have.

[Jim Becker]

I have a woodmaster 5hp planner that I want to hook up to a 30amp breaker, could I get by using 8-3 instead of the 10-3? I have about a 20ft. run from the main panel and would like to use up the 8-3 that I already have.

Yes, you can certainly use heavier wire for the circuit as long as you can physically attach it to your breaker and outlet. The breaker should be no issue and hopefully, the 30 amp recepticle can fit 8 gage wire.

[John K Jordan]

...hopefully, the 30 amp recepticle can fit 8 gage wire.

Tony,

You can get the size of the wire that will fit a given receptacle or breaker from the manufacturer. I believe it's also on the package or the receptacle itself. For example, those I checked on this page http://www.leviton.com/en/products/e...er-receptacles indicate they will accept up to 4 AWG wire.

BTW, 8 gauge is not bad but I really hate working with 6 and larger. I once wired a new service entrance on my house with some left over 0000 (4/0) copper from an industrial site. The copper on this size is nearly 1/2" diameter. Just feeding it down a conduit from the roof was bad enough, bending the wire to fit into the contacts on main breaker in the box was a real trick. The guy from the utility company who connected it to power from the pole was surprised.

JKJ

[Tony Connaghan]

Thanks Jim and John, will definetly check out the 30amp breaker for wire size, I've been purging my shop and will be glad to have a use for that 8ga. wire.

[Art Mann]

I'm not saying it is unsafe or you shouldn't do it but multi-outlet circuits in excess of 20A are a violation of the National Electrical Code, as best I remember.