Hello folks,
I see a lot of talk and concern with duty cycles. Which brings up a question. Of all the welders out there, how many actually regularly overheat their power sources and wish they'd bought a bigger unit?
Hello Red. Did you mean to say "of all the welders on this forum..."? Not possible to survey all the welders in the entire world. 
If you really did mean all the welders out there, in the whole world, then I wish you luck with your endeavor.
Just out of curiosity, are you asking because you feel that a lot of people put way too much importance on this one metric?
If you really did mean all the welders out there, in the whole world, then I wish you luck with your endeavor.
Just out of curiosity, are you asking because you feel that a lot of people put way too much importance on this one metric?
Only time I've wished for a "bigger" unit is when I needed more power, not necessarily a higher duty cycle. IMO, duty cycle limits are really only a factor when you get into production-level work (e.g., the cutting, prep, and sometimes even fit-up and tacking are done separately and the machine in question is just running beads for long periods).
Doesn't mean you have to actually be a production shop to see this happen; job shops can also certainly find themselves in this situation when doing runs of parts.
So here you have to look at the economics of it: What costs more for your shop over time? Upgrading your machine(s) to a higher duty cycle to prevent down time, or the amount of time potentially wasted due to duty cycle limitations?
Either way, if you're not in a production shop, you'll probably find that hitting your duty cycle limit is harder to do than you may think, and if it does happen, it will most likely be very infrequently.
Edit, just to add to the conversation because I sort of treated it as assumption without really explaining it: There are typically two ways to get a "better" duty cycle for a particular amperage. 1) Upgrade to a machine with higher max power so you're not running that machine at or near it's full capacity all the time (i.e., get a 250A machine if you plan to do part runs at 150-200A). 2) Upgrade to a machine with the same power rating, but a higher duty cycle rating at that max amperage, but as you can imagine, those machines can be more expensive.
It all takes planning, and I always advise people to figure out what size machine they will need for what they expect to weld, and then to buy the machine that is at least 1-2 steps above that in power. I've yet to meet a welder that regretted buying the bigger machine, but have known many who lamented getting the smaller machine.
Doesn't mean you have to actually be a production shop to see this happen; job shops can also certainly find themselves in this situation when doing runs of parts.
So here you have to look at the economics of it: What costs more for your shop over time? Upgrading your machine(s) to a higher duty cycle to prevent down time, or the amount of time potentially wasted due to duty cycle limitations?
Either way, if you're not in a production shop, you'll probably find that hitting your duty cycle limit is harder to do than you may think, and if it does happen, it will most likely be very infrequently.
Edit, just to add to the conversation because I sort of treated it as assumption without really explaining it: There are typically two ways to get a "better" duty cycle for a particular amperage. 1) Upgrade to a machine with higher max power so you're not running that machine at or near it's full capacity all the time (i.e., get a 250A machine if you plan to do part runs at 150-200A). 2) Upgrade to a machine with the same power rating, but a higher duty cycle rating at that max amperage, but as you can imagine, those machines can be more expensive.
It all takes planning, and I always advise people to figure out what size machine they will need for what they expect to weld, and then to buy the machine that is at least 1-2 steps above that in power. I've yet to meet a welder that regretted buying the bigger machine, but have known many who lamented getting the smaller machine.
BillE.Dee
- BillE.Dee
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Weldmonger
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Posts:
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Joined:Mon Nov 27, 2017 8:53 pm
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Location:Pennsylvania (Northeast corner)
Hello Red,,,Don't know your location, but being up here in the corner of PA in the summer time does have a effect on the welding. My first welder was kind of smaller than I now need, but oh well. the ambient temps will cause the "duty cycle" to squeeze the machine a bit. You will probably want to take into consideration that fact unless you're working in a controlled enviroment. And like spartan mentioned, you need to consider what you are welding. Getting a machine that is a little bigger won't hurt. It's kinda like going for a ride with your girlfriend...only need 2 seats, but IF your wife is tagging along, you need a truck for swinging room.
well i havn't overheated any and i have some low duty cycle machines (all hobby machines not "commercial spec")RedDelPaPa wrote:Hello folks,
I see a lot of talk and concern with duty cycles. Which brings up a question. Of all the welders out there, how many actually regularly overheat their power sources and wish they'd bought a bigger unit?
the cheap really low duty cycle machine you tend to notice a drop in power as you weld. however thats offset by the metal heating up, so i've not found it to be a problem.
but the old rule of you buy a machine bigger than you need applies. most of the time i use them no where near max amps and i don't do long runs.
for eg one machine is 10% duty cycle at max amps, but at the amps i usually weld at its 60% so i don't have any issue with it.
there is a demo at fabtech where one brand invites anyone to max out there machine. its rated for 60% but i don't think anyone has overheated it.
tweak it until it breaks
Yes, I've hit thermal overload on a Lincoln 140 when welding up a bottle cage out of 2"x2" square tubing about half way through, it really didn't take that long even though I was only doing short runs. It's really not that hard to hit the limit of a homeowner machine during the summer and the fact I haven't on my 210 amp MIG is just because I try my best to avoid doing it.
Just a bit of info, while most modern machines have thermal overload sensors which may or may not protect the machine, buzz boxes do not. You can hit the duty cycle and not realize it because it'll keep welding until it literally melts down, or more likely degrades over time.
Just a bit of info, while most modern machines have thermal overload sensors which may or may not protect the machine, buzz boxes do not. You can hit the duty cycle and not realize it because it'll keep welding until it literally melts down, or more likely degrades over time.