240v help

[bigbearcountry]

I want to install 240v for an electric heater and welder. I'm planning on using a 30amp double pole breaker, but I'm not sure what size wire to use for the wire, I'm thinking 10-2, but want to be sure. The run is about 15-20 feet.

Also, I'm not sure what size box to use for the plug, the plug is wider than normal receptacles.

Attached is some pictures of what of the welder and heater specs.

Thanks!

 

[FordTruckWench]

Also, I'm not sure what size box to use for the plug, the plug is wider than normal receptacles.

The receptacle for that plug fits into a box that normally fits two switches or two 15A receptacles. In other words, get a double wide box.

If you are running conduit, you have the further choice of using a double "switch" box or a square box. The former will be faced with a wall plate, the latter would use a cover that actually holds the receptacle.

 

[gpflepsen]

I want to install 240v for an electric heater and welder. I'm planning on using a 30amp double pole breaker, but I'm not sure what size wire to use for the wire, I'm thinking 10-2, but want to be sure. The run is about 15-20 feet.

10 gauge wire is the correct size to use for a 30A circuit. The distance is no issue.

 

[theoldwizard1]

Also, I'm not sure what size box to use for the plug, the plug is wider than normal receptacles.

There are a lot of different electrical boxes to choose from.

You probably want a 4-11/16" 42 cubic inch square box or a 4" 30 cubic inch square box. Your choice will be dictated by the cover required to go over the receptacle and how the box is going to be mounted.

Some box come with clamp for either MC-BX or NM or no clamps at all.

You can use 10-2 NM (a.k.a. "Romex") but it is hard to bend in tight areas. Stranded wire (THNN/THWN) require some kind of conduit.

 

[wyliesdiesels]

Need more info about the heater.

Welder circuits are wired based on duty cycle and input power.

That welder has 20a input and a 30% duty cycle.

So u need #14 wire and a 20a breaker.

Is that the plug for the welder?

If so, thats a NEMA 6-15 which means u need a 15a breaker...

Its a good idea to label the outlet 'for welder use only' but not required...

Edit: I didnt see the heater pic originally. And i forgot that the 6-15 and 6-30 look the same..
So u need a 30a breaker...

http://m.ecmweb.com/qampa/code-qa-45

 

[scissorman]

If the wiring is going to be covered inside of a wall I would suggest running the larger wiring (smaller gauge number) so that if you choose to install a larger breaker at some point down the road for a larger load the wiring is already acceptable and wont need to be changed. It's ok to go overkill on wiring but NEVER install a larger breaker on smaller wiring.

 

[wyliesdiesels]

If the wiring is going to be covered inside of a wall I would suggest running the larger wiring (smaller gauge number) so that if you choose to install a larger breaker at some point down the road for a larger load the wiring is already acceptable and wont need to be changed. It's ok to go overkill on wiring but NEVER install a larger breaker on smaller wiring.

not true for motor, welder circuits, and A/C circuits...

 

[zmaxmotorsports]

Are the boxes going to be surface or flush mounted?

 

[Norcal]

If the wiring is going to be covered inside of a wall I would suggest running the larger wiring (smaller gauge number) so that if you choose to install a larger breaker at some point down the road for a larger load the wiring is already acceptable and wont need to be changed. It's ok to go overkill on wiring but NEVER install a larger breaker on smaller wiring.

The rules for motors, welders, & A/C equipment, are vastly different then the rules for branch circuits, and they do allow wire size & fuse/circuit breaker combinations that would not be code compliant on a normal branch circuit.

 

[Speedy Petey]

The rules for motors, welders, & A/C equipment, are vastly different then the rules for branch circuits, and they do allow wire size & fuse/circuit breaker combinations that would not be code compliant on a normal branch circuit.

While you and Wylie are totally correct on this code wise, personally I think it is kind of careless to employ these code sections in a residential setting, ESPECIALLY one where the receptacle will get mixed use. If a welder or motor is hard wired that is a different story. Then there is no chance for the circuit being used for something else.

An example is if someone wires a stick welder with a 50A receptacle but only #10 or #12 wire, then the house is sold and the new owner comes along with their nice big kiln and just plugs it in because the correct receptacle is right there in the garage.

As far as the OP goes, that is a 6-30P on the welder, and the instructions clearly also show and name a 6-30P in the picture.
Since this circuit will be used for a heater and a welder the "special" rules for welders goes out the window.

The correct setup for this is 10/2 cable, to a properly sized 2-gang box (or deep 4"sq, or deep 4-11/16sq), with a 6-30R receptacle and cover.

 

[pattenp]

..
An example is if someone wires a stick welder with a 50A receptacle but only #10 or #12 wire, then the house is sold and the new owner comes along with their nice big kiln and just plugs it in because the correct receptacle is right there in the garage.

I agree with you for typical residential use and have commented in the past that a circuit of this nature should just be wired as a normal general use branch circuit because of the possible future use by someone else not knowing the wire is reduced in size.

 

[sberry]

Need more info about the heater.

Welder circuits are wired based on duty cycle and input power.

That welder has 20a input and a 30% duty cycle.

So u need #14 wire and a 20a breaker.

Is that the plug for the welder?

If so, thats a NEMA 6-15 which means u need a 15a breaker...

Its a good idea to label the outlet 'for welder use only' but not required...

http://m.ecmweb.com/qampa/code-qa-45

This is a funny unit. I am not sure if they changed it but it used to list number 8 and a 40 for that machine, me thinks they were sniffing the board clue when they did it but that machine comes with a 6-50 and can be plugged in to 50A circuits.
They are a very good welder with a super arc and were tuned for 030 solid and C25 gas.
Wylie, the Millers and Hobarts do list 14/30 for this class and I havnt seen a new manual on the Lincoln, seems I looked it up once but cant recall.

 

[sberry]

The bottom line is a 10/30 is a tailor made circuit for them.

 

[sberry]

I glanced a min at the online manual, they havnt improved things a bit. That is pitiful.

 

[wyliesdiesels]

While you and Wylie are totally correct on this code wise, personally I think it is kind of careless to employ these code sections in a residential setting, ESPECIALLY one where the receptacle will get mixed use. If a welder or motor is hard wired that is a different story. Then there is no chance for the circuit being used for something else.

An example is if someone wires a stick welder with a 50A receptacle but only #10 or #12 wire, then the house is sold and the new owner comes along with their nice big kiln and just plugs it in because the correct receptacle is right there in the garage.

As far as the OP goes, that is a 6-30P on the welder, and the instructions clearly also show and name a 6-30P in the picture.
Since this circuit will be used for a heater and a welder the "special" rules for welders goes out the window.

The correct setup for this is 10/2 cable, to a properly sized 2-gang box (or deep 4"sq, or deep 4-11/16sq), with a 6-30R receptacle and cover.

Agreed. IMHO a code should be added requiring the outlet to be labeled for welder use only.

Since, like u said, the OP will be using the outlet for dual purposes, it needs to be wired with #10...