HTP Invertig 221 thermal over-load torture test. Real-world results. Very surprised !

General Zod

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So a FlyFishing piqued my curiosity as to what the "real world" thermal limits are on my Invertig 221. By "real world" I don't mean worst-case scenario, but rather what the machine would experience in an average shop.

This was rather impromptu, so I don't have video footage (yet), but the data I'm presenting is factual.

Ambient temperature:

uc


Picture showing machine at thermal overload:

uc


test piece to absorb a lot of heat:

uc



Machine showed 217A on the display. Not sure why not 220A, never really payed attention to it, perhaps just production tolerances.

Time until thermal over-load/shut-down (minutes:seconds):

1st & 2nd done back-to-back, 3rd-5th back-to-back, meaning as soon as the thermal overload light turned off I went back at it at full power.

1st: 4:32
2nd: 3:38
3rd: 3:20
4th: 3:02
5th: 2:51


Those time durations for arc on-time aren't all that surprising seeing as how the machine is rated at 20% duty cycle @ 220A @ 104°F, and the ambient temp was well below that.

BUT...........

I initially "felt" like the cool-down time (until the thermal switch turned off and I was able to strike an arc again) was in the neighborhood of 5 or 6 min, but I wasn't paying too much attention to that part; I was more focused on how long the arc was on. But as I did more and more of those over-loads, I started to pay more and more attention to just how long it actually took to restore itself back to full operation. After the last thermal overload duration of 2:51, I let the stopwatch on my phone keep going to then subtract the time and see just how long it takes to recover so one can get back to welding. Shockingly, the thermal light turned off at 6:30! Subtract the 2:51 that the machine actually had the arc on, and that means that it only took 3:39 to cool down!

So if you go back to the 4th thermal overload, I had the arc on for 3:02, machine cooled down for about ~3:39, and then the 5th arc duration was 2:51 before it overloaded again; that's a total of 9:32. At 9:32 it was overloaded (and would have stayed that way for the next few minutes), so say 10min flat, and out of those 10min, the arc was on (albeit not consecutively) for 5:53. So almost 6 minutes it was arc-on during a 10min span.

Before I jump to any conclusions, I speculated what would happen the next 10min. It would have been off for about 3min (because it was already overloaded), been able to weld for about 2:45 at the current rate of decrease, then another ~3:40 to recover, then on for maybe 30sec before the 10min span is up again. So the 2nd 10min would be about 32% duty cycle. Average that out with the 1st 10min span, and one would be looking at an average of about a 45% duty cycle (over a 20 minute span) at an ambient temperature of 75°F. Not too bad.
 

cathead

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It looks like the mass of the heat sink on the solid state devices was getting warmer and warmer with each weld so each time
you started welding, the times decrease a little bit. It's best not to press one's luck as most (IGBT/transistor) failures are heat related.
So far I have yet to see my TIG shut down but so far have not tried any large weldments.
 

General Zod

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Yes that is correct, each time the entire welder gets more and more heat-soaked, so the arc-time is shorter and shorter each time. Luckily most HTP welders have pretty conservative protection schemes for this kind of thing so I'm not worried. I have luck to spare. :)

Obviously something like this is very un-realistic IMO, as usually there is a need to re-position, re-adjust, etc etc. So all the little starts-n-stops help with the overall cool-down. Over 2-3 full minutes of non-stop welding at this amperage level is definitely not the norm I'd say. At least for non-robots.
 

ahazi

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Does the TIG torch gets very hot too with this type of duty cycle? Are you using water cooling?

I have the HTP Pro Pulse 200 MIG welder which I love and I noticed that during long welding cycles at full current the welder will derate the current after some time without letting you know. You start wondering why the weld is different than few minutes before...

Ariel
 

erikmannie

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I hit the duty cycle on my Miller Dynasty 210DX a few times last week. The ambient temperature was about 85°F, and I was just running one 6010 rod after another at 80A for hours.

When this happens, I just can’t strike an arc. The first thing I do is check my ground. If I have a ground, then I realize that I need to take a break and sweep the floor, wire brush my pipe, etc. This occurred about 3 times in 5 hours.

One school I was at (UBI in Ashland, OR) had 220V Miller Maxstars. The instructor told us to stop welding as soon as we heard the second fan come on! At home, I definitely weld until the machine shuts down; that’s what the second fan is for!
 
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General Zod

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Does the TIG torch gets very hot too with this type of duty cycle? Are you using water cooling?

I have the HTP Pro Pulse 200 MIG welder which I love and I noticed that during long welding cycles at full current the welder will derate the current after some time without letting you know. You start wondering why the weld is different than few minutes before...

Ariel

I am using a water-cooled Weld Tec roto-head. Torch got warm, but nothing compared to the radiant heat you will feel on your gloves from this kind of arc on-time at this amperage level.

On the ProPulse 200, the derating of the current/WFS is not due to time running at full current, but rather you went over-current by likely holding too short of a stickout for that particular wire diameter. The over-current protection is not time-dependent and can happen immediately if one is not careful. Once the machine senses you went over ~220A for a few seconds, then that is when it drops the WFS to prevent premature thermal stress to the internal components. If you were to actually hit full thermal overload while staying "within the boundaries", the welding would cease altogether, entirely and the display would show the "over temp" message, and indicate which component has reached thermal saturation. Some people really hate that from what I've read, but then again it is there for a reason, and will definitely keep the machine working for a long time with such sophisticated protection, IMO.
 

General Zod

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I hit the duty cycle on my Miller Dynasty 210DX a few times last week. The ambient temperature was about 85°F, and I was just running one 6010 rod after another at 80A for hours.

When this happens, I just can’t strike an arc. The first thing I do is check my ground. If I have a ground, then I realize that I need to take a break and sweep the floor, wire brush my pipe, etc. This occurred about 3 times in 5 hours.

One school I was at (UBI in Ashland, OR) had 220V Miller Maxstars. The instructor told us to stop welding as soon as we heard the second fan come on! At home, I definitely weld until the machine shuts down; that’s what the second fan is for!
Sounds odd to me. The 210dx is rated at 125A 100% duty cycle on 208-480V.
 

ahazi

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I am using a water-cooled Weld Tec roto-head. Torch got warm, but nothing compared to the radiant heat you will feel on your gloves from this kind of arc on-time at this amperage level.

On the ProPulse 200, the derating of the current/WFS is not due to time running at full current, but rather you went over-current by likely holding too short of a stickout for that particular wire diameter. The over-current protection is not time-dependent and can happen immediately if one is not careful. Once the machine senses you went over ~220A for a few seconds, then that is when it drops the WFS to prevent premature thermal stress to the internal components. If you were to actually hit full thermal overload while staying "within the boundaries", the welding would cease altogether, entirely and the display would show the "over temp" message, and indicate which component has reached thermal saturation. Some people really hate that from what I've read, but then again it is there for a reason, and will definitely keep the machine working for a long time with such sophisticated protection, IMO.
Thanks for the info, makes sense. I am using exclusively 0.030" wire which works fine most of the time. I think the situation happened when I cranked up the settings to weld 0.250" material which is probably more suitable for 0.045" wire.

I find the HTP Pro Pulse MIG welder to be very forgiving in terms of settings. Time to start practicing my TIG welding for more refined work...

Ariel
 
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General Zod

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No need to switch to 045 wire, IMO. It will do ¼" on pulsed-spray just fine if you switch to a 90/10 or 92/8 Argon-CO₂ gas mix. You can also use 035 wire on the 030-pulse program if you want a bit more amps than the 030-pulse program allows (180A) if you use this voltage offset chart I have developed. It will allow you to reach the full 200A on pulse. But I warn you, your MIG gun will get smoking hot on long runs and you must keep 5/8- 3/4" stickout from the tip to the work.. Keep in mind that the proper gas mix is absolutely required to initialize pulsed-spray operation; "over-volt'ing" without the correct gas-mix is not the correct answer to achieve the transfer method. People have commented to me on the forums that this is what they do and then wonder why their nozzle is literally blue/purple discolored from the overly-large arc plume/cone.

uc
 
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erikmannie

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Sounds odd to me. The 210dx is rated at 125A 100% duty cycle on 208-480V.

Interesting. It must have been a bad ground. There was a lot of slag on the bench when I couldn’t strike in arc. Maybe I was able to strike an arc later because I had cleaned up the slag.
 
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