Wiring for tigwave 250

[sunpeople]

Hello, i am new to this site and have a question on power wires for my new Hobart Tigwave 250. On the name plate it says that if you run it on 230 volts the unit needs 98 amps input for 250 amps output at 40% duty cycle so that would be a 100 amp service with number 2 wires coming from the outside service panel to the welder disconnect switch. I looked in the NEC code book and they say in article 630-11 that the supply conductors can be found by using the current values determined by multiplying the primary current in amperes given on the welder nameplate and the multiplier from the chart in the NEC code book. In my case my welder has a 40 % duty cycle and in the books chart under the duty cycle is the multiplier of .63 and the welders input amps of 98 amps so if i do the math it comes out to 61.74 amps at full power. The old setup i have in my shop is a 150 amp outside service from that i ran a number 6 wire over to a 100 amp sub panel, the number 6 wire has about a 70 foot run from the outside service panel to the sub panel in my shop and between the outside service panel to the service panel in my shop the number 6 wires are protected by a 60 amp fused disconnect. I only ran a number 6 wire when i put in the sub panel because at that time i though 60 amps would be more than enough to run the machines i have in my shop due to the fact that i am a one man shop and i can only run one machine at a time. Under my sub panel i have a 50 amp plug receptacle that i ran my old Miller Econotig from, that plug is protected by a 50 amp breaker. My question for all of you is do i need to run new number 2 wire over to my sub panel from my service panel and from that to a 100 amp service disconnect switch or is the information in the NEC code book right and the number 6 wire i already have installed enough to power the new welder or am i misunderstanding the information i am reading in the code book? Just a little more information the other machines in my shop are a 9X42 Bridgeport mill a 14X40 engine lathe, 8X28 mill drill, 5X6 Horz. bandsaw, 9X15 Vert. bandsaw, 6X48 beltsander, 12 inch disk sander, Darex endmill sharpener, Darex drill bit sharpener, 5 HP. 60 Gal. Horz. compresser, and the new Hobart 250 amp welder. I know what some of you are going to say, that is too many machines for only a 60 amp service but As i said before i am a one man shop and i only run one machine at a time, never two and up to now i have never had any problems because i try to do everything up to NEC code but i just want to be sure that with the new welder i dont have any now. I am open to any input you may wish to add but please NO FLAMES if you think i am doing something wrong just be nice and tell me how to do it right. Thank You

[Broccoli1]

Some one will come along soon but Hit the edit button and put a Paragraph break in there somewhere

[Sberry]

This is about as clear as mud but there are allowances for derating wire for dedicated circuits specific to welding machines, you wouldnt be able to derate them to a sub panel though.

[Sberry]

I have run those machines from 60A service though, you just cant smoke on it wide open. In a home shop how hard are you going to run it would be a factor.

[sunpeople]

Hi sorry for taking so long to answer you but i just got home from the hospitial a few days ago i was in a bad car wreck and broke my left arm and left leg and they had to pin them back together so i may be a little slow in typing and spelling.
I see from your first post that you are not sure what i am asking so i will go over it again per the NEC code book they say (that is if i am understanding it right) that when you set up a welder you are to use the multiplier from the chart in the code book on welders and times it by the duty cycle of the welder to get the wire size to power the welder with.

Now per my first post that comes out to right around 61 amps and what i have is right around a 60 amp service already run over to my shop to power the tools and welder that i already have in the shop now.

So my question is if i only run the welder and nothing else is what i have already in place enough to power the welder or do i need to run another service over to power the welder or could i just remove the number 6 wire that i now have in place that feeds power to my sud panel and replace it with number 2 or single 0 wire.

Now i know that from the code book to handle a 98 amp (thats what my welder uses at 230 volts per the back cover on my welder) load you need a #2 wire but what i am asking is the info in the code book right, or am i not using the info from the book right, before i saw the info in the code book about welders i would have just removed the #6 wire that i have feeding my sub panel right now and replaced it with #2. But when i saw this new info in the code book on welders and duty cycle i said to myself why do all of that hard work and replace the wire i have if i dont have to! Thats the reason for my question, i hope you understand what i am asking better now.

[Sberry]

The code would allow for de-rating this wire if it was a dedicated circuit for this machine, it wont allow it for a feeder to another building or distribution panel.

[hankj]

Sunpeople,

I'd plug it into the existing 50-amp recep you used for the Econotig and weld away. If you find that the braker trips, then it's time to think about adding a new circuit, but I'll bet that, unbless you try building locomotives, you will be able to do all you need to do with what you already have.

Sberry is just trying to emphasize that a derated circuit, while OK for the welder, is NOT OK for a 100% duty cycle appliance that draws that amperage. Then, the wire is too small.

Hank

[sunpeople]

Thank you Sberry and Hankj for taking the time to answer my questions. before i was in my car wreck i did plug the welder in to the plug that i ran the econotig on and it worked fine.

Most if not all of the work i do is stainless steel welding, i do work for two food companys here in town and most of it is light gage sheet metal repair work, but sometimes i do items up to 1/4 to 3/8 inch. I also do a lot of fab work using 1/8 wall and .060 wall S.S. tubing. The most i have set the welder to is 225 amps on the front dial and no problems yet but i just want to be sure that i dont burn down the shop by running the welder on too small of wires, thats why i asked the question that i did

I have a Fluke amp meter at the shop i think i will have my son place it on the power feed wires and just see how many amps this welder pulls at different settings.

I will have my son run a few test at different amp settings and i will post the amp readings he gets here, and then you can tell me what you think.

[MAC702]

It is very difficult to read your first post. We aren't kidding about needing paragraphs.

I don't think it said what size wires are running to the 50A receptacle.

[sunpeople]

Hi Mac to answer your question the wire size is number 6 THHN that runs from the sub panel to the 50 amp plug and it has about a two foot run from the sub panel to the plug. Mac if you read below you will see the wire size that i ran from my meter to my sub panel.

So i hope this is clear now it goes like this a 150 amp main panel and meter from it to a 60 amp fused disconnect, the fused disconnect is mounted right outside of the main meter service panel, then from the fused disconnect you have a 70 foot run of number 6 wire to the main lugs of the 100 amp rated sub panel, this panel has all of the brakers for all of the machines in the shop, then from a 50 amp braker in the sub panel used just for the welder you have a two foot long run of number 6 wire to a 50 amp plug in socket, and into that 50 amp socket you plug the plug from the tigwave welder.

Now i hope you understand this if not tell me and i will try to explane it again. Please dont mind my spelling the docs have me on lots of pain meds right now due to the car wreck i was in a few weeks ago and i am having a hard time seeing the key board right now.

[MAC702]

It was the size of the wire to the welder recptacle that I needed to know. I did get the subpanel wire from the first post.

I would replace the 50A welder breaker with a 60A. That would equal the size of the disconnect to the subpanel and allow the welder to use any available amperage left over from the other machines on that subpanel. The low duty cycle of the machine (relatively) means this will not be a problem.

This is the fast, cheap[er] option, but you may still want to consider a new subpanel.

[sunpeople]

A VERY BIG Thank you to Mac and everyone that has taking the time to comment on my welder! It looks like i am good to go with the number 6 wire i have in place as long as i DONT try to build any Locomotives or run it smokin hot at 310 amps for 30 minutes at a time.

For the type of jobs i do i dont see myself running the welder over 250 amps for more then 1 or two minutes at any one stretch and that will be the rare occasion. Most of what i do is below 150 amps, and the sheet metal repair work will most of the time be low amp stuff and here in a few weeks i will be the proud owner of a Hobart pulser for my machine. I am buying it from Noisy Nova a weld talk member.

Thanks again everyone for your help!!!!!!!! I really appreciate it!!!!!!