Diversion 165 Problem "Poped then smoked"

[H80N]

Is there a formula, or is that an approximation based on experience? It seems to be a common question for people who are, temporarily or permanently, running their welder on a smaller service than required by the manual.

Some people have a limited input, and just increase welding amps until the breaker trips. But that assumes the breaker is the weakest link, and is functioning properly.


But what about those who want a specific output, lower than maximum, and need to determine the proper input wire and breaker?
There was a question asked recently about a Dialarc H-F on an under-sized breaker, that was never answered. (The poster decided to not buy the welder).

For that case, information from O-M 315H, SN: JB 510828
There are 5 rated outputs listed for stick and AC/DC TIG, (pg 12), 3 amp ranges, with 6 volt-amp curve lines on two charts (pg 17), and one fuse recommendation (pg 15). Evidently it is confusing to many people.

It is not as simple as looking at the volt-amp curve and determining output watts, because that does not include the loss due to machine efficiency. (For example, at rated load, my 61F has a 4500 watt output and 10,350 watt input, for efficiency of about 43%. And requires a breaker with 13,800 watt capacity, which is 300% of output).


The poster wanted about 250 amps output. So assuming 250 amps for AC / DC and TIG / stick, what breaker would he need? The required fuse is 150 amps, but that is for 310 amp output, not 250 amp.

The rated input is 90 amps @ 250 output, but that does not give any ‘cushion,’ and presumably a 90 amp breaker would trip. Would a 100 amp breaker be enough?


A solution that has been suggested, is to size the wire for continuous load at 250 amps, (90 amp input); use a full-load (150 amp) breaker to handle peak load at 250 amps; and skip doing the complicated math of sizing the breaker properly. But that violates code and requires the operator to be very aware of the amp setting and duty cycle. It also assumes there is enough 230v available to supply peak demand.

This topic comes up frequently, and could make a good ‘sticky,’ except getting into a risky grey area of breakers and wiring deviating from the O-M and possibly violating code.

Th owner/operator MUST pay attention to parameters..... sometimes you need to TEMPORARILY get by

a careful operator will navigate the situation.... a mindless drone will continue to pop that undersized breaker & maybe start a fire

That derated output guess was based on previous experience

but....

IdeallyYou really want to conform to the manufacturers guidelines

See Table 3-3 in the manual

https://www.millerwelds.com/files/ow.../O353J_MIL.pdf

[Aeronca41]

I'm getting too much information. My uncle who is an electrician recommends a 50 amp breaker and 00 gauge wire. This seems like a ginormous size wire. Common sense tells me that I need to match the power cord that is coming into the machine.

would a 50amp circuit and #4 wire be enough?

Agree-00 wire is way over what you need. And very expensive. #4 copper is fully code compliant assuming 60% duty cycle. Not sure why you would put a 50a brkr on #00 wire? The manual ref H80N provided calls for 110 amp breaker but unless you plan to run this thing flat out all day, 100 a should be fine. And you could get away with #6 wire both legally and performance wise per the manual so long as you stay with a 100a brkr to comply with Art 630. However, I would use #4 if it were mine -- always better to be a little oversize than under. And the longer the distance, the more you benefit from the larger wire.

[Stefen7]

When I build my garage next year, I will wire it for full output, following the O-M.

But the other poster with the Dialarc H-F, wanted to wire it properly, for less than full output (250 amps on 310 amp welder). Ryan and I could only quote the breaker and wire info in the O-M, but that was larger than he needed for only 250 amps output.

The welder is drawing 90 amps continuous at 250 amps output, and a bit more at peak as the arc fluctuates, but a properly sized wire can handle that brief increase.

But a 90 amp breaker will not allow the increase over 90 amps, and would trip.

In your experience, what size breaker would be needed for them to properly run a welder at 250 amps, drawing about 90 amps / 230 volts continuous, with momentary increases?

[Aeronca41]

Personal opinion only-others may have different ideas. If I was planning on 90 amps in a welding application I might go with a breaker the next standard size over 100 A, or just go with 100. Check the link below for typical breaker trip curves-they are only instantaneous devices under some conditions.

http://static.schneider-electric.us/...0600DB0105.pdf

You can see from the graph on page 2 that depending on severity, overloads may be tolerated for considerable periods of time (unless you happen to have old FPE breakers; they will tolerate huge overloads almost indefinitely including after the house fire has already started).

If this was a general household circuit, code only allows for design load of 80% of the circuit ampacity. Art 630 for welders makes the special case.

[ryanjones2150]

FPE breakers are bad bad. Had another house fire last shift caused from the failure of an FPE product. Got me and my FF burned in that fire too. If you have an FPE panel, do yourself a favor and change that mammerjammer out.

[Aeronca41]

FPE breakers are bad bad. Had another house fire last shift caused from the failure of an FPE product. Got me and my FF burned in that fire too. If you have an FPE panel, do yourself a favor and change that mammerjammer out.

Scary! I try to take.every opportunity to warn people about those things, so they don't need guys like you and your team showing up at their house. Your last your last shift is proof that there is still a need for warnings.

[ryanjones2150]

It is far more common than a lot of people think for a federal pacific breaker panel to burn someone's house down. I even have a class I teach here about these miniature weapons of mass destruction. And can you believe the ace hardware here sells replacement breakers for those panels? What a shame.

[Stefen7]

Thank you Aeronca41 and H80N for the information.

The fact that electrical fires happen was the reason to ask for the correct size breaker to supply a welder at less than max amps, so we can give good advice in the future. When the O-P asked if he could run a Dialarc H-F off a dryer outlet, Ryan’s answer was “NO”, and all I could say was the O-M requires a 150 amp breaker (for 310 amp output). Neither of us could recommend a breaker size for 250 amp output.

With information like this, us junior members can help others with the basic questions, leaving you more experienced senior members to tackle the really difficult questions.

[H80N]

Thank you Aeronca41 and H80N for the information.

The fact that electrical fires happen was the reason to ask for the correct size breaker to supply a welder at less than max amps, so we can give good advice in the future. When the O-P asked if he could run a Dialarc H-F off a dryer outlet, Ryan’s answer was “NO”, and all I could say was the O-M requires a 150 amp breaker (for 310 amp output). Neither of us could recommend a breaker size for 250 amp output.

With information like this, us junior members can help others with the basic questions, leaving you more experienced senior members to tackle the really difficult questions.

They should call a local licensed electrician....for their particular situation...

otherwise the danger and liability are too great..... it will be money well spent

We have gotten petty far off topic....(AND Best Practices.....)

I would like to hear how GGODWIN is doing with his new SYNC 250

[Aeronca41]

They should call a local licensed electrician....for their particular situation...

otherwise the danger and liability are too great..... it will be money well spent

We have gotten petty far off topic....(AND Best Practices.....)

I would like to hear how GGODWIN is doing with his new SYNC 250

+1. Thanks for steering us back. :-)

[H80N]

+1. Thanks for steering us back. :-)

I worry about people getting hurt by some inadvertant act causing mayhem on their person or property....

a little bit of knowledge can be a dangerous thing........misunderstood or misapplied

[ggodwin]

I got the 250 going. I don't have it moved to my shop yet but I basically have it moved so I can finish a project that is two weeks a delayed.

my welds are similar to what they were before. But, I think I'm not operating the welder correctly. My tungsten is splitting down the tip. Other times is just flat out cooks away really quick.

any suggestions?

[H80N]

I got the 250 going. I don't have it moved to my shop yet but I basically have it moved so I can finish a project that is two weeks a delayed.

my welds are similar to what they were before. But, I think I'm not operating the welder correctly. My tungsten is splitting down the tip. Other times is just flat out cooks away really quick.

any suggestions?

What Tungsten...??

You want..2% Lanthanated (Blue) Tungsten... Taper ground...

??? what size..??? Amperage...??......

Sounds like you are running 2% Thoriated (RED).... that does NOT like AC

[ggodwin]

1.5% Gold Lanthanated 3/32" tapered Dow
125 Amps

[H80N]

1.5% Gold Lanthanated 3/32" tapered Dow
125 Amps

2% Lanth is better...................

Here are a couple of Tungsten comparisons

https://www.youtube.com/watch?v=bpanERwagaU

https://www.youtube.com/watch?v=DzEuV83UGMY