Wire size for TIG

[12husky]

I have a Lincoln Square Wave 355 TIG I am wiring into my new shop. When I had it in my garage it was on a 50 amp breaker, but will be putting it on a 125 amp breaker. I am planning to hard wire it with 50' of SOOW cord. I know wire sizing is different for welders compared to other equipment.

What is the proper gauge for this? 240v split phase.


-Matt

 

[William Payne]

Here you go, first section regarding installation. I imagine this is the model you have?

http://www.lincolnelectric.com/assets/servicenavigator-public/lincoln3/im467.pdf

 

[12husky]

Here you go, first section regarding installation. I imagine this is the model you have?

http://www.lincolnelectric.com/assets/servicenavigator-public/lincoln3/im467.pdf

Thanks. The manual lists wire sizes for in conduit; is it the same for SOOW cord?


-Matt

 

[William Payne]

You may want to check the NEC regulations regarding the use of cord. I don't know what your rules are. Are you talking about using the cord from the machine to the wall? If so what is the cord currently attached to the machine?

The rules change regarding from machine to wall, then wall to electrical panel.

 

[12husky]

You may want to check the NEC regulations regarding the use of cord. I don't know what your rules are. Are you talking about using the cord from the machine to the wall? If so what is the cord currently attached to the machine?

The rules change regarding from machine to wall, then wall to electrical panel.

This wire is for from the wall to the machine. There is no cord permanently hooked to the welder since it is meant to be hard wired. I had 8/3 SOOW cord on it when it was hooked to the 50 amp breaker.


-Matt

 

[sberry]

It would be big, number 2 or better. When you had it on 50 it was under wired but under breakered to protect the wire. This is slightly different than the smaller machines with more limited duty cycles.

 

[William Payne]

Yeah with the voltage you are running creating a higher current draw thats going to be a big cable. I don't have a chart for amps ratings for the wire sizes you guys run but you would be getting close to number 0

 

[matt_i]

Here is what I would do (and did). I hardwired my Syncrowave 250 to the corner of a bench where it sits, piece of large liquidtight conduit back to the PVC hard conduit, so the transformer & cooler unit can move ever so slightly if needed. Tig is all done at the bench where I can sit. If I want to stick weld, I have a very long stinger and ground clamp which can easily reach out to the driveway.

FWIW I used #2 THHN for a 250A machine. I think you have a 350A (nominal) machine. Obviously it has some sort of setting for the amperage its trying to deliver @ 100% pedal, one could successfully dial it down and use a smaller input wire, but if you are intending to do thick 1/4"+ AL then my opinion you should wire for max amperage. Nothing ***** electrons like trying to weld aluminum.

 

[William Payne]

In my personal opinion if you have the power available and want to use it across its full amp range then wire appropriately. I personally feel that under wiring a machine of that nature is very limiting. However a machine like that is meant more to sit in a fixed place and you bring the work to it. I myself have a syncrowave 351 which is a similar output to your machine.

 

[sberry]

I have a blue one, I think it is 2/125 if I recall. Pic 2 is an oldie.

 

[William Payne]

Just while its on my mind, should you ever want to run it on an outlet and plug. I don't know whats available in the USA but I found a german company that makes plugs and receptables in voltages from 110v all the way to 500v and handle amps from 16 to 125. I am looking into this for when I soon move my syncrowave 351.

 

[matt_i]

Just while its on my mind, should you ever want to run it on an outlet and plug. I don't know whats available in the USA but I found a german company that makes plugs and receptables in voltages from 110v all the way to 500v and handle amps from 16 to 125. I am looking into this for when I soon move my syncrowave 351.

I think the problem is going to be cost...some hardwires and lugs are just a few dollars. An industrial duty specialty plug & receptacle combo is going to be a few hundred dollars if I had to guess. The 60A pin & sockets are typically mechanically interlocked to a disconnect handle so that the plug can't be unseated while the circuit is drawing energy. The disconnect must be 'OFF' to release the interlock.

 

[William Payne]

I think the problem is going to be cost...some hardwires and lugs are just a few dollars. An industrial duty specialty plug & receptacle combo is going to be a few hundred dollars if I had to guess. The 60A pin & sockets are typically mechanically interlocked to a disconnect handle so that the plug can't be unseated while the circuit is drawing energy. The disconnect must be 'OFF' to release the interlock.

Yes it would not be a cheap endeavor. I just wanted to put it out there.

 

[sberry]

Look in the manual, it will be there.

 

[William Payne]

Look in the manual, it will be there.

Yeah I linked the manual for him in the second post which had the requirements. But he was not sure of whether the rating were different between cable and cord.

 

[wyliesdiesels]

Thanks. The manual lists wire sizes for in conduit; is it the same for SOOW cord?


-Matt

IIRCC SOOW isnt made larger than #2 which is 95a. Thats why manu only lists hardwire instructions.

Nec table 400.5(a)(1) lists ampacities of cordage.

U would need an industrial type cord for larger wire sizes which will be expensive.

Cheaper to hardwire.

 

[sberry]

BTW, what was the listed wire size. Put 2 on it with 100. It wont burn up. If this is any kind of hobby shop and it has been running on 50 then its not a big deal.

 

[12husky]

I weld a lot of SS and aluminum primarily for boats. My new shop(36x48) will let me pull boats in and work on larger projects. That is why I was hoping to be able to roll the welder around the shop.


-Matt

 

[wyliesdiesels]

BTW, what was the listed wire size. Put 2 on it with 100. It wont burn up. If this is any kind of hobby shop and it has been running on 50 then its not a big deal.

Actually for this unit it depends on the mode its running on.

If using balanced current then #6 is good.

But if unbalanced then #2 THHN is required.

 

[sberry]

Is 6 listed for it? I havnt looked at the manual but havnt seen a 300A ****** tig call for less than 2 but havnt read every one,,, so,,,
Ok,,, I guess so. Since its listed as the supply it wouldn't bother me a lot to use it as a cord especially if a guy keeps it to a dull roar with the duty cycle. I burnt the torch doing a long weld on a boat, just didn't pay attn., input wire was not warm but torch was,,, ha