Using a 60' extension cord with a ThermalArc 185

2ga wire for each conductor? Whoa!

The power meter is attached in a very convenient location, actually -- it's attached to an outside wall right next to the garage. I'm pretty electrically (ok, electronically -- not much experience doing electrical work) inclined.

Is there a good webpage on the subject?

before you say not doable..... consider a few thing ,

you will unikely to use that TA at maximum power where it would draw

32 amp of your 220V.

if you use the supplyed air cooled torch , you will be stopping very often.

getting new filler rod, reposition your self, grinding tungsten and so on,.... that extention cord will never get hot. also since it is not in the walls it gets plenty air cooling. you can alway check, feel how hot it gets during a period of welding.

now .... 60' that is fairly long .......

safety first : get it hard wired if you use it often.

Take a look at these online voltage drop calculators:

The current does not know the difference between an extension cord and the 'extension cord' in a conduit installed by an electrician. However you do need to consider the safety of the installation.

Using one of the above calculators:

120 feet of 8 AWG with 35 amps flowing: the voltage drop is just under 7 volts

Probably an acceptable voltage drop, you would need to check the specs. for the welder of course.

You could probably fabricate your own cord for less than hiring an electrician. However if you are not really comfortable with doing this kind of stuff play it safe and hire an electrician.

snipped-for-privacy@sneakemail.com wrote:

I ran a 180 amp lincoln buzz box using a heavy duty extension cord from the house when I was a kid. I regularly ran 1/8th electrode at 120 amps AC. I spliced into the stove circuit. I never did blow a fuse. The wire never heated up. I am not sure of the gauge but it originally had been used to drive an 220 V air compressor by a painitng contractor. The OD on the cord was about 3/4 inch. ( three conductor) You are going to spend a good dollar purchasing heavy extension cord sixty feet long. Randy

#2 is way out of line. #8 or even smaller should be fine. Even #12 would give a voltage drop of around 12V at 32A, which shouldn't be a problem since the welder will run on 208V. The NEC allows a higher ampacity than normal for conductors supplying a welder, depending on the welder's duty cycle, that accounts for the intermittent nature of the load, so the #12 may be OK on that criteria as well. You'd have to check the NEC and know the welder's duty cycle to be sure.

Ned Simmons

The ThermalArc is rated for a 30% duty cycle.

Not really any good web-pages per-se, but for about the cost of the extension cord you can do it yourself. Is your breaker box directly below the power meter? are the house and garage connected physically? if not how is the power run out there now? (underground conduit etc?) Basic power tools (drill hole-saw, pliers, screwdriver, and fish-tape helps but it can be done other ways depending on what route you gotta take it.) are all that's required.

Hopefully your house is not brick, and it's standard hollow wall construction.

I also apologize, I had my electrical calculator set for DC when I did the v-drop calculations, thats why I got the big deuce. :)

I have made many a LONG extension cord for welders using underground romex. I think mine are #6 wire. If you have to coil it up for storage it makes a nice 3 foot diamter coil on the ground.

Underground romex has tougher insulation and is round, not flat.

I use a #8 AWG 3/S (8 gauge 3 strand ) , mine is only 30' long this has worked well for my Miller 251 and 210 , I also use it with the Thermal arc 185.

the #8 /3S should have 40-50 amp rating at least. if you decide to go this route, buy your cord from an electrical house bulk.... instead of going to home depot/too expensve. A #8 should work for just about any welding machine you throw at it. keep in mind that a 60' long in this size will be quite heavy.

good luck

I often see the underground-type romex for sale as 'used' in our local metal scrap yard. I also sometimes see lengths of rubber-type extension cord too in quite heavy gages including #8 and so. Maybe a place to start if you're looking for extension power. Ciao, David Todtman

I use a 6/3 cord 75 feet long to run all my welding needs as my welding area is way out back. I use a 10/3 50 feet long with the mig machine, usually plugged into the 6/3 to reach the back alley.

Ive measured voltage drops and they are well within tolerences.

gunner

Rule #35 "That which does not kill you, has made a huge tactical error"

I Strongly suggest looking for surplus electrical shops or the like. I buy my extension cords by the pound . I have a number that are 0/4 and didnt cost the price of a 16/3 at the hardware store.

The connectors are the pricey bits.

Gunner

Rule #35 "That which does not kill you, has made a huge tactical error"

A number 10 power cord will be fine for this use, however as you say the meter and distribution panel is on the outside of the garage it may be easy to place a 4"x4" box and receptacle in the garage. You could use the same breaker that feeds the plug in the basement. Don't run the dryer and the welder at the same time, or you will trip the breaker. This would be much cleaner, as you would not have to have a sixty foot extension cord running through the house.

Mike

Yes, since the breaker box is on a wall near the garage and it's a matter of one hole to drill for the wire, we'll probably install a permanent outlet box in the garage eventually.

For the moment, so I can get welding, I picked up the appropriate socket at Loews and am going to try the 12/3 cord. What amperage should I keep the welder under -- or just "low enough that the cord stays cool?"

My understanding of the NEC (and I'm not an electrician and this is usenet ) is that the ampacity of the conductors supplying a 30% duty cycle welder must be at least

rated primary current X .55

or in your case

32A X .55 = 17.6 A min conductor ampacity

The breaker serving the welder may not be larger than 200% of the rated primary current. So in your case 12 ga NM (romex) fed by a 60A max breaker is OK, assuming the voltage drop is acceptable.

The numbers above apply to permanent wiring and I'm not sure how much is applicable to temporary extensions. Also, I don't believe that romex is strictly legal for use as a temporary extension, so use the information as you see fit.

Ned Simmons

THANK YOU guys! :)

On your advice, I tried the 12/3 cord I have lying around. After far too much fiddling and a bit of machining the connector contacts to fit the ancient-and-nonstandard wall socket, I got everything to work. Though I haven't tried the tig on full power, I was able to run some great beads and the cord stayed quite firmly at room-temperature.

Thanks again for all the help :)