Input Power Requirments for the 250EX

[sschefer]

I posted this in the General forum and didn't get anything so I'm posting it here and trying to be a little more clear.

Does listed input power of 45amps refer to the total current in a 220v circuit or is it the requirement of one leg with the total actually being twice as much. In other words do I need a dual 50 amp breaker or a dual 30 amp breaker to run the machine?

[performance]

Circuit breakers are rated for the entire circuit. The amps are the maximum inrush amps for the 250EX and represents the max TOTAL requirement.

[HEMI]

A 40 amp 2-pole breaker is more common and will do the job fine.

You will need the following for single phase instillation...

2-Pole 40 amp breaker
#8 2 conductor plus ground
50 amp 250 receptacle
50 amp 250 volt cord end
2x3/4 inch box connectors

If you use the prefab receptacle you will only need one connector and you will not have to buy a box and cover to house it.

[geezer]

A 40 amp 2-pole breaker is more common and will do the job fine.

You will need the following for single phase instillation...

2-Pole 40 amp breaker
#8 2 conductor plus ground
50 amp 250 receptacle
50 amp 250 volt cord end
2x3/4 inch box connectors

If you use the prefab receptacle you will only need one connector and you will not have to buy a box and cover to house it.

A 40 Amp breaker will not do fine, I had a 40 amp breaker and the only way I could rely on it to work was to reset the breaker quickly after it popped and restart the 250 ex before the capacitators bled down, you can run it on a 40 amp breaker only if you don't pull over 200 amps or have a long extension cord. The 250 ex pulls 45 amps at start up and an older 40 amp breaker like I had would just pop and pop, I have since switched to a 60 for my PP 80 plasma cutter and the 250 EX. A 50 would do fine but I choose a 60, as I had it on hand in the panel. From the panel to my plug on the wall a distance of 18 inches I have no 6 on all 3 conductors, No 8 would work,

[sschefer]

Circuit breakers are rated for the entire circuit. The amps are the maximum inrush amps for the 250EX and represents the max TOTAL requirement.

Thank you, that's the answer I was looking for.. Total inrush. Therein lies the beauty of inverters based welders!

[sschefer]

A 40 Amp breaker will not do fine, I had a 40 amp breaker and the only way I could rely on it to work was to reset the breaker quickly after it popped and restart the 250 ex before the capacitators bled down, you can run it on a 40 amp breaker only if you don't pull over 200 amps or have a long extension cord. The 250 ex pulls 45 amps at start up and an older 40 amp breaker like I had would just pop and pop, I have since switched to a 60 for my PP 80 plasma cutter and the 250 EX. A 50 would do fine but I choose a 60, as I had it on hand in the panel. From the panel to my plug on the wall a distance of 18 inches I have no 6 on all 3 conductors, No 8 would work,

If the main panel and subpanel are wired to code, meaning that L1 and L2 are on separate phases, then the 250EX should never trip a 220v 40amp breaker. You're giving it 80 and it only needs 45. In fact I would probably try a 30a first just to be on the safe side.

I've opened up many a main panel and seen a lot of srange things but the most common is that the homeowner had taken power for a subpanel from two available breakers but they were not side by side and just by coincidence they were both on the same phase. Another common thing is that they will bring the neutral and the ground over from the main panel and tie them together at the sub panel just like it was done at the main. The ground needs to be isolated from the neutral at the subpanel.

Either one of those things are common, cause fires and damage equipment. That breaker blowing is telling you that you've got a problem and if the welder is not defective then it's likely that your wiring job is.

Thanks for the response.

[sschefer]

A 40 amp 2-pole breaker is more common and will do the job fine.

You will need the following for single phase instillation...

2-Pole 40 amp breaker
#8 2 conductor plus ground
50 amp 250 receptacle
50 amp 250 volt cord end
2x3/4 inch box connectors

If you use the prefab receptacle you will only need one connector and you will not have to buy a box and cover to house it.

Thanks Hemi, the shop is wired to code. I've been running my Lincoln 225 off a 40 (80 total) but the circuit is wired for 50amps. My problem is that I could only pull 100amps off the main panel to the sub panel in the shop or I would start short change the house.

I'm getting a 250EX because I have a lot of 1/4" Al to weld and the 80amps I have available is not enough to sustain the Lincoln for more than a couple of inches of high penetrating welds. I'm running a water cooler and lighting on the other 20 amp circuit and it also supports other equipment via 20amp co's occasionally. What can I say, I like my water cooled torch and my other toy's errr I mean tools.

There are some creative wiring solutions that could be done but all of them involve robbing peter to pay paul. The miserly inverter style EX solution is the best and safest.

[performance]

The rating on a breaker is just that, it is NOT for the individual legs. IF a 220V breaker is rated for say 70 amps, it is not two 70 amp 110 legs. Geezer is correct.

[sschefer]

The rating on a breaker is just that, it is NOT for the individual legs. IF a 220V breaker is rated for say 70 amps, it is not two 70 amp 110 legs. Geezer is correct.

Humm, so what you are saying then is that the inrush current is 45a and that a 50amp breaker is needed. That means that the 250EX inverter based welder is no more efficient than the Liconln Precision TIG 225 transformer based welder.

[performance]

This unit also runs on three phase, reducing amp draw a considerable amount.

Max inrush is 45, but actual running is 36 amps at the low end of 220V.

It IS more efficient. Way more... You need to compare apples to apples. The Lincoln 225 is a low duty cycle machine and Lincoln is "playing" the numbers to cover up horrendous performance specs.

1)Lincoln Rated output is 90 amps at 100% duty cycle.
2) Input at rated output (90 amps) is 42 amps.
3) OUR rating is 45 input amps @ 250 amps output with 60% duty cycle, with a rated max running amps at 36.
4) OUR 100% duty cycle rating is at 200 amps.

You have to read VERY carefully. I took this information straight from their PDF.
http://content.lincolnelectric.com/p...ature/e337.pdf

In fact they don't even list their max amps or duty cycle at full use on their site that I can see. Maybe I missed it. However, I have used this very machine, and there is no comparison whatsoever to ours.

See our 225 machine and compare evenly to theirs if you want a true understanding.

[geezer]

If the main panel and subpanel are wired to code, meaning that L1 and L2 are on separate phases, then the 250EX should never trip a 220v 40amp breaker. You're giving it 80 and it only needs 45. In fact I would probably try a 30a first just to be on the safe side.

I've opened up many a main panel and seen a lot of srange things but the most common is that the homeowner had taken power for a subpanel from two available breakers but they were not side by side and just by coincidence they were both on the same phase. Another common thing is that they will bring the neutral and the ground over from the main panel and tie them together at the sub panel just like it was done at the main. The ground needs to be isolated from the neutral at the subpanel.

Either one of those things are common, cause fires and damage equipment. That breaker blowing is telling you that you've got a problem and if the welder is not defective then it's likely that your wiring job is.

Thanks for the response.

There is nothing wrong with my wiring
I think you need to relearn the code on breakers and breakers with tie bars and how they must be labelled , you cannot have 2 25 amp breakers tie bar'd together without relabeling them to indicate the total load. ie 50

Using 2 25 amps not tie bar'd together is permitted but foolish, suppose one blows and you tinker around in the machine with the other is leg alive, then ZAP you are dead. The purpose of the tie bar is to make both legs go off when one side blows.

Buy a proper 50 amp tie bar'd breaker which is essentially 2 25's bound together and properly labeled as a 50 for total load.

[sschefer]

Whoa, Mark, I wasn't comparing welders I was comparing current requirements. Never said you're welder wasn't more capable.

Let me ask you this for clarification. What gauge is the wire for the power cord on the 250EX. That will answer all my questions for me.

Thanks

[maxspeedman]

A 50A 240V breaker is constructed with two 50A breakers tie bared together.

The current is equal in each of the two hot leads so the breaker has to be the same. A 50A breaker is never two 25A breakers tied together, it is always two 50A breakers with a tie bar.

Max

[sschefer]

A 50A 240V breaker is constructed with two 50A breakers tie bared together.

The current is equal in each of the two hot leads so the breaker has to be the same. A 50A breaker is never two 25A breakers tied together, it is always two 50A breakers with a tie bar.

Max

Correct. Some 220 breakers can be deceiving by having a single throw but these are actually two separate breakers tied together inside the plastic body.

Therin lies the question about the max current on the EX. The power plasma 60 needs 40amps at max power on 220v. I run it on a two 30amp breakers tied with a tie bar. The breakers are on different phases.

Really, all I want to know is what size breaker the EX needs. I don't want to over size the breaker.

[sschefer]

Geezer, you must be right but if you don't mind, I'll keep doing it the way I have for the past 40 years.

Thanks for the response.

[performance]

sscheffer,

You are not understanding the issue at play. You cannot ADD the sum of the two legs together to get the actual amperage. You cannot use two 30 amp breakers tied together to get a 60 amp breaker, whether with a single throw or a double throw(not to code). A 60 amp breaker is a 60 amp breaker whether it is single or double throw. The rating is the same(if you can find a 60 amp single throw). IF you add the two amps together to get your total amp requirement, then you are woefully under sized on the breaker if the requirement is sixty amps. In other words if you try to use two 30's you still only have a 30 amp 220V breaker. And if you use one double throw breaker that has 30 amps on each branch, it is still only a 30 amp breaker.

Additionally, my main point of the issue with the 225lx lincoln is that you are ONLY evaluating the current demand of the 225lx lincoln by the requirement of the machine at only 90 amps output because the way they are reporting their requirements. They are giving you a "rated" power requirement and officially stating their rating at 90 amps. This is their 100% duty cycle rating. This is where things get confusing. When operating at full power (225 amps) the current demand of the lincoln will be (estimated) in excess of 60 amps, possibly 70 amps. However, The NEC gives SPECIFIC instructions with welder requirements for both breaker sizing and wire gauges, that allow rating a circuit according to the duty cycle of the welder. Since lincoln give the 100% rating, then the unit COULD be miswired instead of stating the actual maximum requirement and duty cycle. There are many caveats in the ruling of the NEC that entail hiring a knowledgeable electrician to properly wire a welder circuit. Perhaps this is what should have been prefaced at the outset: Get a qualified electrician.

IF you are running a 40 amp unit on two thirties tied together, then you are running it on 1 30 amp breaker not a 60.

Scroll to page 175...http://books.google.com/books?id=8cT...rcuits&f=false

[maxspeedman]

To size the breaker and wire size for a 250EX you need to refer to the NEC Article 630 Section II. The key numbers are I1eff and I1max, both of which are marked on a label at the back of the 250EX. The I1eff is 36A and the I1max is 45A.

You need to go into the details of the NEC to determine the actual wire and breaker that you need, but for the 250EX, a #8 wire gauge with a 50A breaker will work very well and will meet code.

Max

[HEMI]

By the way, 2 breakers tied together with a tie bar you put on. Is not the same as a 2-pole breaker you purchase with or without the tie bar.

Putting a tie bar on 2 single breakers are fine for split plugs or 2 circuits going to say the 2nd floor of a house, sharing the same neutral.

But when feeding a 220/240 volt device, the breaker should not only be mechanically tied together but also be thermal magnetic (Internally) connected to each breaker.


Now lets get back to some welding

[sschefer]

Performance, thank you. I don't believe that two 30 amp circuits make a 60amp circuit. Somehow I've manage to convey that incorrectly in my writing.

Our split phase, energy deficient, U.S. electrical systems don't help the matter.

So if in-rush is 47a peak then I'll size the breaker to a 50amp. Question answered. Thank you, I should have just said that in the first place.

I hope to have the Lincoln sold today and will be ordering an EX hopefully sometime this week.

[sschefer]

Paid for me EX today. Should see it sometime late next week. I'm within the overnight via ground distance for UPS.