I need a single phase outlet!

[mickey cassiba]

I'm in a bind! I need to do some welding in a part of the plant that has 3 phase 240 & 480.(No 1ph) I only have an antique Lincoln 180AC which is 1ph. My electrician is out for the holidays, and the welding needs to be done ASAP.
I have basic electrical skills, and I have heard that a 3ph circuit can be split down to 1ph. If it is possible, can anyone here give me simple instructions as to how to do this?
My only alternative is to build a 100' cord for the welder, which will cost in excess of $600. Not feasible for the job.
I've searched the forums, and have not found an answer that I can understand.
Help!
Mickey

[Greg Portland]

Assuming your welder is 240V 1ph:
Connect your hot wire to one of the phases, connect neutral to another phase and ground to ground. Keep in mind that you will only get 208V using this method (~75% of the power).

ASsuming your welder is 120V 1ph:
Connect hot to one of the phases, connect neutral to neutral and ground to ground. This will give you a full 120V.

[mickey cassiba]

The welder is a n old 230V lincoln. At 208V do you think I can get the heat I need to make an emergency weld? Not structural but a lot of shear action. Only has to hold til I get my electrician back.
Thanks Greg.

[Wayne Hendrix]

More than likely the 240V is actually 208V 3 phase anyway and your welder will work fine. However, I wouldnt follow the above advice without an electrical multimeter to check what voltage you are actually getting.

If there are only 4 holes in the outlet then you should get ~120V between the ground and each of the "hots," and you should get ~208-220V between any two of the "hots." You need to tie your welder to two of the "hots" and the ground. If you get more than ~120V between any "hot" and the ground dont use that "hot".

If there are 5 holes in the outlet then you should have a ground, a neutral and 3 "hots." Do the same thing as I just described. The only difference is you will get ~120V between the ground and each of the "hots," ~120V between the neutral and each of the "hots," ~208-220V between any two of the "hots," and continuity between the ground and neutral.

If what I just described is not perfectly clear I would recommend finding someone to make the connection for you. If the connection is made wrong you could burn up your welder, the breaker, the wiring or even possibly injure or kill yourself.

[mickey cassiba]

More than likely the 240V is actually 208V 3 phase anyway and your welder will work fine. However, I wouldnt follow the above advice without an electrical multimeter to check what voltage you are actually getting.

If there are only 4 holes in the outlet then you should get ~120V between the ground and each of the "hots," and you should get ~208-220V between any two of the "hots." You need to tie your welder to two of the "hots" and the ground. If you get more than ~120V between any "hot" and the ground dont use that "hot".

If there are 5 holes in the outlet then you should have a ground, a neutral and 3 "hots." Do the same thing as I just described. The only difference is you will get ~120V between the ground and each of the "hots," ~120V between the neutral and each of the "hots," ~208-220V between any two of the "hots," and continuity between the ground and neutral.

If what I just described is not perfectly clear I would recommend finding someone to make the connection for you. If the connection is made wrong you could burn up your welder, the breaker, the wiring or even possibly injure or kill yourself.
Wayne...I've got a good multimeter, and while not a certified electrician, I have a lot of experience chasing circuits and such. I intend to open the supply box to one of our machines and temporarily wire in a welder outlet. Between yours and Greg's advice I think I have it hand. However I do have a lot of respect for electricity, and if I am unsure at any step, I will stop and call in a welder. I just have a broken door, a long weekend, and a crime-prone area to deal with, as well as a company in financial turmoil. Trying to save as much as I can, but won't risk life, limb, or equipment.
Thanks guys, and anyone else that wants to chime in, I've got about 16 hours left to get this done.
Mick.

[Bruce Wrenn]

Can you get hold of a small MIG welder, and a hundred foot 12-3 drop cord? I can run my MIG of my generator. Is this a possibility? This should do for emergency repairs. If not, can you get hold of some #3, or #4 rebar? Weld some together (tacked is enough) to reach needed location from where welder can be spotted. Clamp lead to one end, and use a second lead at the other to do welding. I wouldn't use frame of the building as a ground though. Can you rent a set of leads from rental company?

[Wayne Hendrix]

You should be good if you know how to wire the welder outlet. Just use the multimeter to find the proper wires to connect your outlet to and then use the meter to check the outlet once its wired.

If you are doing this first thing in the morning PM me and I will give you my phone number in case you have a question on the job, however, I am only available until 9am Mountain Time.

[Glen Butler]

As I understand phased power, you cannot just take any two of the hots in a three phase plug to run a single phase welder because they are different phases. When using 240V single phase power both the hot lines are from the same phase. I just don't want to see you ruin your tool or worse. Be careful.

I was just doing a little research, and apparantly you can connect a single phase load to a three phase system by connecting to two live conductors (240V) or one live and neutral (120V).

[Rick Christopherson]

Mickey, You got your answer in the first response from Greg. Stick to that. Some of the follow-up answers are confusing and some are erroneous. Greg has properly advised you, and I agree with his posting. He said what I would have said.

(oops, Greg should not have used the word "Neutral" in his first paragraph, but as long as this did not confuse you, everything else is correct. Only the word is wrong, but the intent is correct.)

[mickey cassiba]

Thanks to all! I finally got ahold of a friend who teaches at the local Vo-Tech, and he verified the info I received here. The weld came off without a hitch, and the temp is disconnected. all ready for the production gang this morning. Saved the company a lot of money, and made me look like a freakin' genius.
Also got permission to enroll at the Vo-Tech on the company dime.
Thanks guys.
Mick

[Roger Frazee]

You said you were going to temporarily wire into a supply box for a 3 phase machine, so I am assuming you mean at a receptacle point where the machine is plugged in. but no matter the only thing I would add for future reference is be sure that the circuit your pulling power from will support the welder... both the breaker and wire size. Obviously it did but just an fyi. The Lincoln 180 is 208 or 240 volt and for full output (180 amps) it requires a 25 amp branch circuit. It needs a 20 amp branch circuit at rated output of 130 amps. The recommended max. breaker is 40 amps. Even if the branch circuit that existed serving that 3 phase machine was 14 awg I would suspect things would go ok if the arc isn't struck for too long. The breaker would only protect conductors and if too small would have tripped. And protection varies for 3 phase machines with motors. My point being in your case and the welder you were using gave you a good chance of success but remember to check the branch circuit for compatibilty with the amperage of the welder.

[mickey cassiba]

You said you were going to temporarily wire into a supply box for a 3 phase machine, so I am assuming you mean at a receptacle point where the machine is plugged in. but no matter the only thing I would add for future reference is be sure that the circuit your pulling power from will support the welder... both the breaker and wire size. Obviously it did but just an fyi. The Lincoln 180 is 208 or 240 volt and for full output (180 amps) it requires a 25 amp branch circuit. It needs a 20 amp branch circuit at rated output of 130 amps. The recommended max. breaker is 40 amps. Even if the branch circuit that existed serving that 3 phase machine was 14 awg I would suspect things would go ok if the arc isn't struck for too long. The breaker would only protect conductors and if too small would have tripped. And protection varies for 3 phase machines with motors. My point being in your case and the welder you were using gave you a good chance of success but remember to check the branch circuit for compatibilty with the amperage of the welder.
The machine in question is hardwired to it's own dedicated circuit(60A 240V 3Ph)with an 8ga supply line.

[Greg Portland]

Glad to hear that it all worked out.


As I understand phased power, you cannot just take any two of the hots in a three phase plug to run a single phase welder because they are different phases. Erm, no. Think of an equilateral triangle. Pick two points... they are the same distance as any other two points. Each leg is 120 degrees out of phase relative to the other two. Yes, they are all different phases... that is why you don't get a true 240V when you connect the welder in this manner, you get 208 (=sqrt(3) * 120V).

[Rollie Meyers]

In the US there are 2 different systems supplied by PoCo's or customer owned transformers, 208Y/120 volts where any two lines will be 208V between them & 120V from any line to neutral, and 120/240V delta, where any line to line voltage is 240V and between 2 of the legs it's 120V line to neutral but the 3rd leg (Req. by the NEC to be the "B" phase but can be found anywhere :mad:) the reading will be 208V to the neutral, this one cannot be used for any single pole loads, and this is normally used by some PoCo's where the 3 phase load is small & it's a cheap way to supply it over 208Y/120V.

[mickey cassiba]

Too deep for me, at this point in time. But I am enrolled in the next session of our local vo-tech's electrical technician program.I guess the guys upstairs figure it'll be cheaper to grow their own electrician. And yes, I told them that a couple of semesters can't compete with a career of industrial installation and service. They seem okay with that. So I guess it's back to school for me.:D
Mickey

[Roger Frazee]

Good for you Mickey

Keep on getting training, schooling and take your license testing, backflow anything you can get. Will serve you well.

Before I retired my company decided to get rid of our skilled trades and shop us out to a local electrical contractor and trashed all the repair parts inventory. Our building was high bay and they have to pay $500 now to get one HPS fixture bulb replaced....rental on a scissor lift + delivery and labor plus service call. Last I heard they are rethinking due to all the lost production time from breakdowns. In most cases since we were all familiar with the equipment and plc's and motor control cabinets we had them going again in short order. Now they are down for many hours .... they don't like this cause it effects their bonus pay....too bad. Bad economic times tend to make companies take hard looks at what they feel are over paid employees and determine they can get rid of them and do just fine. So protect yourself from this situation by knowledge in the skilled trades and you will always have a way to make a living regardless what a bunch of shirt and ties think of your value to the business. You certainly gave them a lesson with your quick thinking and resourcefulness .... good job. My biggest smile came when I went to work for the company that had the electrical contract with my old employer ...... I sure wish you could have seen the look on the plant managers face when I stepped out of the truck....sat down and waited for the scissor lift to get there....:)

[Tom Veatch]

...Before I retired my company decided to get rid of our skilled trades and shop us out to a local electrical contractor and trashed all the repair parts inventory. Our building was high bay and they have to pay $500 now to get one HPS fixture bulb replaced....rental on a scissor lift + delivery and labor plus service call. ...

Sounds a little like my old company. The "parent" company sold all our computer/network/telephone installation from the servers to the wall plugs to a vendor and outsourced that part of the operation. That wasn't our "core", you see. Well, it had a noticable impact on that quarter's bottom line and probably earned some suits a nice bonus. But by the time I retired a couple of years later, I was in a position to know that money had been given back to the contractor many times over.

Sometimes, common sense gets lost in the business school models.

[Roger Frazee]

Yep.... funny how this thinking seems to be the trend these days. I remember trying to deal with a few computer issues with tech support based in India.... that was an experience....:) That company came close to bankruptcy as their customer service was sourced outside the USA and they made the good ole shame list of the top 25 companies with the worst customer service.

The fiasco here in KC right now is Sprint/Nextel...they are not long for this world if they keep losing customers. I just read where they are closing call centers ...so go figure...:rolleyes:

Sorry for the off subject....