Help me choose a new welder!

[aczlan]

I think the biggest issue, folks say, is having potentially twice the current available on the breaker than what a traditional 120V breaker would supply. So, you have a 40A breaker 230V wired to Nema 14-50, and at the end of the cord you tie one of the legs to a 120V receptacle. I read in another thread that you're potentially supplying 40A to your failed grinder (if it failed) - but really, are you? You're only supplying 1 of the hot legs to the duplex, so that's half of 40A, so it's just 20A, and 20A receptacles at 120V are not out of place in a working shop are they?

Incorrect. A 240v 40 amp circuit is TWO 120V 40 amp circuits, NOT two 20 amp circuits..

Aaron Z

 

[CNC Dan]

Correct me if I'm wrong, but the way the Nema 6-50 Plug is wired, there's no Neutral - two hot legs and one ground. Because of that, you're actually only carrying 15A per 120V leg, NOT 30A on any one conductor.

The details of why this is so, I forget, it's been a really long time since the rudimentary AC power classes I had two decades ago, but in 120V wiring you'd be trying to carry all the amps on one wire, on 230V each wire does half.

Not so. You have the same current on the two hot wires on a 240 volt circuit.
And you have the same current on the one hot and one neutral wire on a 120 volt circuit.

But you can get the same power as a 120 volt circuit with half the current when you are using 240 volts.

So for the same power, higher voltage will require less current.
And wire is sized to carry current.
So you can use smaller wire when on a 240 volt circuit, than you could on a 120 volt circuit.

 

[Colonel Monk]

OK, yeah, it took a ridiculous amount of time to find that in print, that the current is the same as 120V on each leg. Effing ridiculous why it's difficult to find all aspects of information instead of just part of it in several different locations..... Anyway, you guys were right...

Mudd, Aaron, Dan - I get it that it's the same amperage on each 120V leg, and I've always known that you half the current at 240. I had to sell my old man on the concept when he bought a hot tub, he thought that installing 240V would cost more....

What led me astray thinking it was that way, is this miller manual saying that it's OK to use a 14 gauge extension cord! I didn't say so, but before I wrote anything I scratched my head thinking "huh, 30A is generally 10 AWG wire..." or at least it is for 120V wiring. So I thought "Oh! it's because each leg is doing half the total work". I stand corrected.

So, the only thing I can figure though, is that they are permitting the usage of 14 AWG for both 120 and 240 (with 120 half the length) because of the duty cycle. If you follow it straight, on high power you are only welding 2 minutes in 10 for 120V, and 3 minutes in 10 for 240V. Or, it's an outright mistake.

This is a different application than say, a 240v air compressor that runs and runs and runs when you're sandblasting, and there's not necessarily the kind of start up load you see with an air compressor either.

 

[Colonel Monk]

I suppose none of that really matters anyway, as I have no plans to run my welding equipment on a 14 AWG extension cord, whether they say it's OK or not.

Check out this article on wiring a Nema 14-50 receptacle: The 50-amp 120/240-volt 3 pole 4

Seems a pretty good way to go - you can tap both 240 and 120 either by building the dist box like I mentioned, or by creating adapters to pull 120V off from it. Makes the investment in pricey copper wire a little more universal.

The uses that I have for this are:

RV with 50 Amp Service at twin 120V
Welder/Plasma at 240V
Air Compressor down by our river side (we use the air drill to drive lags underwater for dock maintenance)
120V Grinder/Drill/Work Lights

A plus, is that instead of buying a $100 12 gauge extension cord for Nema 6-50, you can find these RV cords on sale and do it yourself. Maybe not for less necessarily, but it would have way more capacity.

 

[newbury]

I bought a large bottle of 75/25 and the HF welder cart w/drawers to hold everything. Very impressed with the cart too. Watch for a sale and use a 20% coupon.

Or better yet use a 25% off coupon!
41341964 is good until 5 Dec.

 

[CNC Dan]

I suppose none of that really matters anyway, as I have no plans to run my welding equipment on a 14 AWG extension cord, whether they say it's OK or not.

Check out this article on wiring a Nema 14-50 receptacle: The 50-amp 120/240-volt 3 pole 4

Seems a pretty good way to go - you can tap both 240 and 120 either by building the dist box like I mentioned, or by creating adapters to pull 120V off from it. Makes the investment in pricey copper wire a little more universal.

The uses that I have for this are:

RV with 50 Amp Service at twin 120V
Welder/Plasma at 240V
Air Compressor down by our river side (we use the air drill to drive lags underwater for dock maintenance)
120V Grinder/Drill/Work Lights

A plus, is that instead of buying a $100 12 gauge extension cord for Nema 6-50, you can find these RV cords on sale and do it yourself. Maybe not for less necessarily, but it would have way more capacity.

Look around for an "octopus box" or a "contractors box". It will have a cord and plug for 3 pole 4 wire, and several 120 volt and 240 volt outlets and 'breakers.

They are used on jobsites to bring power in from the temporary service. If you can't find one with the right plugs and outlets, you can copy the design to make your own.

temporary power distribution box - Google Search

 

[Colonel Monk]

Look around for an "octopus box" or a "contractors box". It will have a cord and plug for 3 pole 4 wire, and several 120 volt and 240 volt outlets and 'breakers.

They are used on jobsites to bring power in from the temporary service. If you can't find one with the right plugs and outlets, you can copy the design to make your own.

temporary power distribution box - Google Search

I'll check that out.

I was off on the price of the cable. if you buy a premade "welding extension cord" like 10/3 or 8/3 they are around $200 for 50 feet. I'm sure I can build one for half that.

 

[ThomasH]

I'll check that out.

I was off on the price of the cable. if you buy a premade "welding extension cord" like 10/3 or 8/3 they are around $200 for 50 feet. I'm sure I can build one for half that.

I bought a 50 foot 8/3 welder extension cable off of ebay about six months ago for $80 including shipping. I bet if you check around you can find some better pricing.

 

[T Connolly]

About the need for a chop saw if you have a plasma cutter. I have both, The plasma cutter is great for rough cuts, holes, getting through thick stock etc but you need a good chop saw for good clean ended cuts and precise angles. I also have a metal cutting band saw that I really like. I like to jig everything precisely before I tack it. Watch out for high powered magnetic clamps. They're ok for tacking things but will draw your arc in funky directions on long beads. Have Fun!

 

[looch]

Timely thread as I'm looking at welders in this range also. The main thing I'm wondering is what Lincoln plans to do about their 180 class machines. The MSRP ranges from $900 - $1000 and their new 210 is under $1100. Regardless of whether or not you're interested in a 210, it has to have a bearing on the price of the 180's: either they will have to be significantly reduced or they will be discontinued. The competition will also have to respond. The dealers (Miller included) I have spoken to agree.

Personally, I get the same feeling as Mike:

My vote would be for the miller 211 or the Hobart 210, depending on if you care about infinite voltage control. The reason I personally choose those is because they are made in the USA. The new Lincoln sounds good on paper but doesn't give me much a warm fuzzy feeling. It's assembled in Mexico, but for the price I'm guessing it's nearly entirely Chinese parts...

, but I want to think that prices will come down as a result of this unit.