Auto fan shutoff sensor?

[performance]

Um, ray, yes it should reset automatically. At least on every Everlast unit I have run past the duty cycle intentionally, it will. IF it won't it is because of a current/voltage cause.

Andy duty cycle of 100% does not mean it will run continuously at 160 amps. It only means it will run 10 minutes at 160 amps since duty cycle is based off a 10 minute period.

[parkour]

In this event, how long must it be allowed to cool after the 10 minutes has elapsed?
What kind of event would cause a current/voltage issue that would make the light to go red and require a power cycle?

[everlastsupport]

I myself (on the AC/DC TIGs) have always had to power the units off to reset the OC (red), but maybe since I was sure it was cool enough and safe to restart. Maybe there was a timer running, but I have never seen one shut off either. Mind you Ray and I do repairs, that might affect our mental timers at the bench.

As far as the 100amp tripping, that's not normal and something to look into, flyback anode too close to something, etc..

I had my personal MIG-250P OC once when I powered it and struck the arc at 21-22 volts, reset it (by hand) no wait and ran it for hours. No idea why, and this was many many months ago and I still use that 250P to date. So on occasion, weird things happen.

So we need to figure out why it's tripping, I was going to mentioned it the other day but saw others were working with you here on the forum and did not post.

As far as how long to leave off, that depends on what tripped it. Andy, does yours reset without a power off? I would wait at least 15 minutes if is was under a close to duty load.

[todmorg]

Um, ray, yes it should reset automatically. At least on every Everlast unit I have run past the duty cycle intentionally, it will. IF it won't it is because of a current/voltage cause.

Andy duty cycle of 100% does not mean it will run continuously at 160 amps. It only means it will run 10 minutes at 160 amps since duty cycle is based off a 10 minute period.

Wouldn't a 100% duty cycle be 10 minutes on, 0 minutes off?

[performance]

Technically, It would, until 10 minutes 1 second mark... After 10 minutes, all bets are off. Europeans use a 5 minute standard. For all you troubled by duty cycle out there, should take note: Just because it is a 100% duty cycle machine out of 10 minutes DOES NOT mean it is 100% for 11 minutes or 20 or even 1 hour. Basic math says when you see the % sign, it means that it is a percent OF another number. 100% of 10 is 10 minutes, not infinity. If it goes 11 minutes, it means that somewhere you may need to give it a rest after 10. Duty cycles aren't that linear either, so, at a point it starts to fall off and does so fairly rapidly.

[todmorg]

Wouldn't 60% be 6 on, 4 off, 6 on, 4 off repeating for infinity? That would make 100% 10 on, 0 off, 10 on, 0 off repeating for infinity.

If this is not correct, please let me know so I don't over duty cycle my welders.

[parkour]

Probably even want to leave the unit on if it overheats so that the fan continues to run and bring in fresh cool air.

[redbeard]

Wouldn't 60% be 6 on, 4 off, 6 on, 4 off repeating for infinity? That would make 100% 10 on, 0 off, 10 on, 0 off repeating for infinity.

If this is not correct, please let me know so I don't over duty cycle my welders.

Bingo. If 100% isn't really 100%, how exactly is an industrial user supposed to do his calculations?

[performance]

Wouldn't 60% be 6 on, 4 off, 6 on, 4 off repeating for infinity? That would make 100% 10 on, 0 off, 10 on, 0 off repeating for infinity.

If this is not correct, please let me know so I don't over duty cycle my welders.

NO. It does not. Again...the duty cycle is based on a narrowly defined time of 10 minutes of operation at a given ideal conditions with a standard temperature of 104. Humidity, dirt, and general air circulation, and ambient temperature, input volts, cabling etc can affect the duty cycle. TRYING to run it to the limit and being legalistic about it is not what duty cycles are about. They are there to give you an idea of the amount of time that the unit should be able to run without a period of rest. The units have temperature sensors in them, not timers that figure out a complicated mathematical formula. These can vary by a few degrees when things kick in, or depending on dirt, or buildup, they may not work accurately at all. Duty cycle is a COMMON SENSE thing...Its not something a smart person does in a legalistic fashion to "push" the limits of the welder.

A more practical example: What's a car's top end? Typically its governed for safety right? Even performance machines, have rev limiters on them to keep them from going over speed and floating a valve or throwing a rod. But does anyone with common sense think this is a good idea to run the car against the rev limiter all the time? Yes the engine is protected...but is it a common sense thing to do?

But young kids, and the emotionally immature may wish to keep the car racing at top rpm just because they can. But does anyone want to buy that car after some kid had it?

[zoama]

So you've welded 9 minutes on your 100% duty cycle... how long in minutes does the welder need to cool before you weld again in optimal conditions ?

[performance]

Guys,
This is basic math here...100% of 10 does not mean its 100% of 11 or 15 or 60...or infinity.
After 10 minutes of use, at the 100% duty cycle window...the welder could very well go into overheat in the 11th, 15th or whatever minute the temperature senses its had enough. These numbers are not published or even valued because unless it is on a robot, no one typically will use it any where near the 60% duty cycle at maximum amps...Even on a robot, there are starts and stops.

Duty cycles are NOT figured by a complicated formula a welder when he is welding. No one says, OK , just welded for 5.59 minutes and now I have to let it cool down precisely 4.41 minutes before starting back to weld. Or I have welded on and off in 3 minute increments at this amperage, so my duty cycle is X. Its something that is intuitive.

The exception to this would be something like sub arc welding where a machine does have a rating based off a higher unit of time or a larger amp capability to keep normal welding with in normal temperatures.

[zoama]

If Mark welded for 9 minutes how long in minutes would Mark let the welder cool before Mark welded again under optimal conditions ?

[todmorg]

I have a CNC plasma table that uses a Hypertherm plasma cutter. When I checked with Hyperthem they said to size the cutter for 100% duty cycle at the required amperage, this would allow for continous use. Should it have been rated in a different manner?

[performance]

Again, (Zoama)
To ask that question is not to understand the point.

People mistakenly believe they are welding for a long time, in reality a single weld rarely lasts more than a couple minutes before you break, reposition, clean or some other activity.

Welding at or near the duty cycle of 60% on say the 250EX would require a fire suit. Its not an easy or comfortable machine. The human duty cycle limiter would kick in after a couple minutes.

Even answering the question you pose Zoama, lacks information. IF you were to weld 9 minutes, so? What is the duty cycle at the amps you are welding. What is the temp? What is the humidity?

IF you were welding at a 100% duty cycle level, and you welded 9 minutes, you'd be needing no rest until you got to 10. But after 10, you'd probably want to rest a minute or two before resuming.....Lets look at it this way...one more time.

Lets say, in easy round figures duty cycle is 90% at 100 amps at the current abient temperature and humidity. We can weld for 9 minutes at 100 amps before needing a technical 1 minute break. OK, now follow this...IF you need a one minute break a 90% duty cycle, a unit that has 100% duty cycle can weld the full 10 minutes... BUT all you are saying is that it will weld continuously at 100 amps for 10 minutes. A few amps higher or a degree or two hotter may change that value to 90% again. You cannot "choose" which unit You want to serve as the basis for figuring duty cycle, such as an hour. Just because a welder has a duty cycle of 90%, it does not mean it will run continuously 90% of an hour long cycle before a break, and then just give it a 6 minute rest to cool. Similarly, a 100% cycle does not mean you can weld 1 hour continuously. You must take a break. The value of time needed for rest is not defined, but it is moot.

You have been running at 10 minutes straight with a 100% duty cycle, you cannot complain if the welder kicks into protection mode in the 11th minute. Once you near or exceed 100% of the 10 minute time limitation, you are operating the welder in an abusive manner. I've seen some things that say you should actually rest a full 10 minutes after a full 10 minutes of welding...others at least 5 minutes.

[performance]

Hypertherm rates things a little differently: See here for JC's explanation (last one).http://www.cnczone.com/forums/hypert...n_cutting.html
In their world, he says for every minute on, that many minutes rest. His statement is not exactly true in the purest sense of most companies definition of duty cycle, but would also support what I have been taught about over 100% operation.
Some of their equipment does carry a 100% rating for basically an infinite period of time...so as I said, some companies due to the nature of their use do put a different time rating on their units.

[todmorg]

My tig is also used on a rotary welding positioner, its not a welding robot, but with quick part changes it can lead to very high production rates. How do I calculate what happens after the first 10 minutes? I am not looking to push the unit to its limits, I need to know what the limits are, so I can stay well below them.

Example- I need a car that can run down the highway at 70 miles per hour 100% of the time ( 100% duty cycle @ 70 mph ) for extended periods, it would not be practical to stop for an undetermined amount of time at the end of a 10 minute cycle to let it cool, and it has to be capable of passing at 100 miles per hour 10% of the time ( 10% duty cycle@ 100 mph ), even though most of my driving time is at a much slower speed ( 300% duty cycle @ 45 mph).

[zoama]

Again, (Zoama)
To ask that question is not to understand the point.

People mistakenly believe they are welding for a long time, in reality a single weld rarely lasts more than a couple minutes before you break, reposition, clean or some other activity.

Welding at or near the duty cycle of 60% on say the 250EX would require a fire suit. Its not an easy or comfortable machine. The human duty cycle limiter would kick in after a couple minutes.

Even answering the question you pose Zoama, lacks information. IF you were to weld 9 minutes, so? What is the duty cycle at the amps you are welding. What is the temp? What is the humidity?

IF you were welding at a 100% duty cycle level, and you welded 9 minutes, you'd be needing no rest until you got to 10. But after 10, you'd probably want to rest a minute or two before resuming.....Lets look at it this way...one more time.

Lets say, in easy round figures duty cycle is 90% at 100 amps at the current abient temperature and humidity. We can weld for 9 minutes at 100 amps before needing a technical 1 minute break. OK, now follow this...IF you need a one minute break a 90% duty cycle, a unit that has 100% duty cycle can weld the full 10 minutes... BUT all you are saying is that it will weld continuously at 100 amps for 10 minutes. A few amps higher or a degree or two hotter may change that value to 90% again. You cannot "choose" which unit You want to serve as the basis for figuring duty cycle, such as an hour. Just because a welder has a duty cycle of 90%, it does not mean it will run continuously 90% of an hour long cycle before a break, and then just give it a 6 minute rest to cool. Similarly, a 100% cycle does not mean you can weld 1 hour continuously. You must take a break. The value of time needed for rest is not defined, but it is moot.

You have been running at 10 minutes straight with a 100% duty cycle, you cannot complain if the welder kicks into protection mode in the 11th minute. Once you near or exceed 100% of the 10 minute time limitation, you are operating the welder in an abusive manner. I've seen some things that say you should actually rest a full 10 minutes after a full 10 minutes of welding...others at least 5 minutes.

All we were looking for was your example and we can extrapolate from there. No need to over complicate it with "intuition" or infinitely variable tooth pulling and such.

[performance]

The best guide you have is the temperature limiting device at this point. Whenever you go over 10 minutes there is not a duty cycle established. If you hit it a time or two, then back off. Its going to vary.

[todmorg]

Would there be a good spot on one of the heatsinks to mount a thermocouple to monitor internal temps?

[redbeard]

Would there be a good spot on one of the heatsinks to mount a thermocouple to monitor internal temps?

I would think right next to the overtemp sensor would be an appropriate place.

Mark, are there specs available on what temperature the protection kicks in?