Welder/Plasma supply wireing, need homework graded

[Western]

Good morning,

Have thoughts (scary) and a plan and I'd like opinions on "the plan" please

Millermatic 185 calls for 40a breaker at 230v
Plasma runs 50a breaker

Millermatic 185 and stand alone plasma, both have standard 6-50P 220v plugs

I am putting in a 220v-50a circuit for the plasma, 50' 6/2 run to 2, 6-50r 220v receptacles (side by side pretty much). Since I don't use both at the same time, I'm thinking I can use the same supply for both machines even though the welder draws 10 less amps? IIRC, I have seen similar in other's shops but not sure of the margins and if this is even doable.

Am I thinking this correctly?

Thanks for your thoughts

 

[workinonit]

I did the same thing. I stacked 4. Miller Syncrowave 200, Millermatic 251 and 180 and TD plasma cutter. Also made a 50 foot extension so that I can get them anywhere in the shop or outside the door. Sometimes farm equipment doesn't travel well to the welder.

 

[Western]

Thanks, that is what I have seen in several shops. I also have a 25' 6awg extension cord I will use primarily if I need to move the welder around. Didnt think the difference of 10 amps would make any difference, especially how much welding eq is wired on 220v using 2 hot, 1 common.

BTW, sometimes I can't even get farm equipment to pay attention, so I know what you mean there!

 

[the old grind]

I ran all my welding outlets 10-50r (three flat blades) for commonality and to handle the 225 & 250a welders. AC Miller 180s, AC Airco 225, Everlast MTS, plasma, couple HFTs. (DC stick, MIG) I bought an adapter for the 6-50 'welder' plugs most stuff comes with these days.

My extension cord is 20' long, 10-50, and 6 Ga. It's just long enough to get me going outside the garage or in/near the barn. btw, All my welders are on carts, have wheels, or sit HFT 18" x 24" moving dollies, and all are used with the 10-50 extension and/or adapter.

 

[herm0016]

your outlet can be whatever. I run all my 220 circuits as 14-50 outlets. this way I can use any of my 220 stuff anywhere. it does not matter what the thing you are plugging into the wall is, The breaker is there to protect the wire in the wall, not the appliance.

think about a lamp and a 120 circuit, none of your lamps or cell phone chargers draw 15 amps. they use what they need, and the maximum is 15 amps for a circuit.

you should run 4 wire. its not going to cost much more, and you can them plug more, different things into that spot. and its harder to add one later.

 

[Western]

Herm, the logic I was using is basically the same as your lamp reference, just a bit more heat on the line I'm running.

I have the 6/2 as it was free, my cousin uses it in his AC business and has a roll. I like free when I works out!

 

[Sberry]

The wire needs to be 2 conductor with ground and 10 cable or better. The 40A is the breaker size for that machine when the minimum wire size is used. The manuals can be confusing so,,, if it comes with a 50 plug then it can be used on a 50 circuit
I don't own a 6 cord, use 10 on them. The breaker does NOT protect the wire in the wall for thermal, the applied or the calculated load does. However when you add multiple receptacle it becomes a general circuit the same way 120v with multiple outlets does. The only time a breaker does this is in case several items are plugged in to the same circuit.
I recently did a welder with 12/30 with 2 but each wire was a home run to the breaker, only 1 outlet to the wire. On other dedicated (except for welders) all the stuff must match. It's not for overload in the typical sense but it implies the circuit is sufficient and current limited for proper short circuit interruption
The breaker in a dedicated outlet is simply an off on switch and for short circuit, both in the circuit wire but also within the connected equipment. A buzzer has a 12 cord and legal to use 12 wire with 50A breaker. An outlet that has a 14-50 must use 6 as it is for a range or large trailer. There is no exception. You can use a 14 cord and 30a plug on some equipment. The load is limited by the machine and it's internals are sized or it has additional protection (similar to 180/200 wire feeds) to allow it on bigger circuits. Reason they list a 30 is due to the fact the minimum wire is 14. The 240 units like the 180/190 actually come 12 cord (limit for 50) to allow use on common welder circuits. The new MVP come with 14 cord but the adapter is special hence the warning about modifying it. Once it's cut off it would be limited to 30.
The breaker does NOT provide thermal to common 120v except for multiple loads. It is however current limited for short circuit. Any listed equipment is designed to tolerate or short 20 in the event of a fault. Think about light fixtures or even air conditioning and even other dedicated outlets but fixtures. 16 wire to a lamp holder. No opportunity for the housewife to come along and plug a vacuum and heaters to those 16 wires, they don't make a lamp that screws in to that base that can overheat the wire, it's thermal limited by the load but needs to be large enough to trip in the event of a fault.
AC units are like this, 40A breaker to 12 wire but they are hard wired, no outlet available for potential overload.
Power strips have a 14 cord and little reset. It's really not a breaker proper, it's a thermal overload as they have 5 recepts. It's still is only allowed on a 20 as it and connected equipment depends on the circuit for fault protection.

 

[Sberry]

There is a lot of assumption as to how this works as evidenced here. My explanation may not be clear, others may help or ask for clarification of needed and maybe it explains it a different way.
An electric range is an example of this. 50A breaker, 6 cord to the rest of it all spliced to the cord. All the internals except the clock (which has a fuse or other means) all the other wires sized for 50 faults regardless of the load and the combination of all them within a 50A load, as long as nothing faults its an off on switch.
Some equipment like my pressure washer uses the same controls as does 120V models and use 1/2 the current but are twice the size. Instead of adding additional breakers they simply increase the size of the leads to be adequate for larger faults from the circuit breaker.

 

[Western]

Sberry, I sure am not a electromagician, very clear as I spelled "wiring" wrong in my thread header lol

Isn't there a difference in running a 50a say to the washer, or stove where 6/3 wire (or other /3) since that can run 110/220? multi circuit use? 220 here and leg for 110v? At least that's how i understand that . From what I understand, 6/2 is common say for like exterior AC condenser and 6/3 often used for interior air handler as they often have 110/220 features.



My welder does specify on the label "Minimum 10AWG" or something to that effect.

 

[Sberry]

The minimum wire listing is normally for single circuit in pipe. For cable a size larger. Anything modern that uses 2 voltages is sposed to be 3 conductor plus ground. Its actually 120/240. If its single voltage like a welder 2 conductor and ground. I believe you said 185, this is a way older model. I have read most of the manuals and looked it up again for giggles, 26A in at rated. Its listed with 10 wire, I didnt look at the duty cycle though. Its plenty of wire for this little machine, I would have figured 12 for it but they also list circuit at 128 ft which is a quite a ways. Ok, I look again, its a 60% machine, very heavy duty. Its why they have such a heavy wire for a 185 plus hey went up a size for distance. At 30% and 75 ft it would be a 12 wire unit.