Auto fan shutoff sensor?

[Trip59]

I read through this whole thread, and not to sound flippant, but it seems the optimal solution to me is to buy a bigger stereo.

If I'm in my shop, there is noise, from the gable vent, the 20" shop fan, and the lathe/drill/grinder/compressor/welder/whatever is on at the moment, etc. I just crank up the stereo and carry on. I have enough quiet all week punctuated by only the clicking of the keyboard.

That said, when welding, I leave the power on until I need to change or adjust something (for personal safety and to not blow a circuit) or until I'm done. Seems to me, the fan can't run too long and the more it runs, the quicker you can hit the next cycle and the longer the next cycle will be (up to the max) as it will have been cooling during the break.

[performance]

The advent of fan on demand is marketing based, and certainly not centered around increasing the life of the unit. Although there are plenty of rhetoric about it keeping components cleaner inside for longer life, the reality is that most of the inverters especially name brand companies utilize "wind tunnel" designs that pretty much eliminates the problem as it is. The noise is a minor issue as anyone that is a true welder contends with much more than that noise in a real welding shop. The hobbyist may be annoyed by the noise of the fan, but it is generally overcome with time. The fan noise generated is much less than the cooling fan running continuously in the corner of the shop all day.

[Ray]

[QUOTE=Trip59;15648]I read through this whole thread, and not to sound flippant, but it seems the optimal solution to me is to buy a bigger stereo.




Well I have never even considered the fan noise. my old CHwelder's fan is so quite I have to check to see if it's working. I like the fact you can tell it's running, LOL.
Watching Jody’s latest video he complains about the noise the miller makes when the fan kicks in. I think I’d rather have a constant noise rather than have it change the way it sounds in the middle of welding. I think I’d have a tendency to look at it to see what was up.





welding is usually preceded and post-ceded (? I doubt that’sa word) by a bunch of grinding around here, so the welder sound is minor in comparisonand usually kind if a relief.

[67cudafb]

I am with Trip between the air compresser and all the large fans running in the shop don't even notice fan in the welder, crank up the rock n roll.

[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]

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?

[performance]

No, I don't have them myself. Though the sensor may have markings, and I am sure each unit has a different threshold.

[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).