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Discussion Starter #1
So, long story short, I'm a welder, and I'm tired of dealing with my welder's pathetic duty cycle. So I've done some research and found couple 240v fans that I'd like to install to improve air flow. Here's my question: most of these fans run at about 240v/.18A, and from what I understand the output of the outlet is 240v/40A. If i were to wire my fans into the main lead for the welder, what can i do to step down the amperage?

PS try to keep it simple for me please, i can hold my own with electronics but i dont know all the jargon.

Thanks!
 

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You don't need to do anything to step down the amperage.
The fan will use what it uses.

How will the fan help increase the duty cycle?
Do you want or need the fan to run all the time, or just when you strike an arc?
 

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Discussion Starter #3
Welders have a thermostat, much like a car. When things (mainly the transformer) get too hot, it trips the thermostat and wont let you strike another arc until it closes again. "duty cycle" is how much time you can actually spend with an arc- 40% duty cycle means you can weld for 4 minutes, then wait for 6 for it to cool down again. The fan will help move air across the transformer, keeping it cooler for longer.
Also, thank you for the quick response.
 

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Discussion Starter #4
Also, some guys who have more electronic experience have wired fans like this to operate only when the thermostat is engaged, whereas most I have heard of just run off the main power switch, and stay on all the time, which is the setup i plan to use.
 

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what can i do to step down the amperage? Thanks!
You don't have to control the amps !
The impedance of the load is what controls the amps flowing !

So in your case the impedance of the welder would be much lower than that of the fans,
so that high amperage will ONLY flow thru the welder !
It will not flow thru the fans,
because they will have a much higher impedance,
so only a small amount of current will flow thru them !

Be real careful brother ! you clearly dont have a grasp on electricity 101 !

:thumbsup:
 

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Time would be better spent looking for a better welder.
 

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Also, some guys who have more electronic experience have wired fans like this to operate only when the thermostat is engaged, whereas most I have heard of just run off the main power switch, and stay on all the time, which is the setup i plan to use.
Ayuh,.... You'd want 'em runnin' whenever the welder is powered up,...

After it shuts down is too late,....

I don't think it's gonna help 1 bit though,....

The welder needs Bigger capacitors, 'n Bigger windin's,...
Or just a Bigger welder to begin with,...
 

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Discussion Starter #8
You don't have to control the amps !
The impedance of the load is what controls the amps flowing !

So in your case the impedance of the welder would be much lower than that of the fans,
so that high amperage will ONLY flow thru the welder !
It will not flow thru the fans,
because they will have a much higher impedance,
so only a small amount of current will flow thru them !

Be real careful brother ! you clearly dont have a grasp on electricity 101 !

:thumbsup:
Yeah, it's all coming back to me now. Hey, at least I have common sense on my side. I was really tired when I posted this last night so I just needed some help using my brain. Thanks for all the help everybody.
 

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Discussion Starter #9
Ayuh,.... You'd want 'em runnin' whenever the welder is powered up,...

After it shuts down is too late,....

I don't think it's gonna help 1 bit though,....

The welder needs Bigger capacitors, 'n Bigger windin's,...
Or just a Bigger welder to begin with,...
Duty cycle is a part of every welder, nothing you can do about that. All you can do is extend it. And the name-brand welders that cost 3-4 times more than mine have fans usually, and a 20-30% longer duty cycle on average.
 

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Changing things on the welder is not going to make it run longer. What will happen is that you will end up either burning up the wiring, or the Transformer winding's. Then you end up with bigger issues.

It helps to know the mfg & model of this welder. If you are looking at heavy duty welding. You really need a decent DC welder.
 

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Duty cycle is a part of every welder, nothing you can do about that. All you can do is extend it. And the name-brand welders that cost 3-4 times more than mine have fans usually, and a 20-30% longer duty cycle on average.
Ayuh,.... I know, I've got a garage full of 'em, mostly name brand welders,...

My point is, Just a fan ain't gonna change squat,....
 

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I quite agree !
Adding fans might help a little !
But I doubt that you will see a substancial improvement !
There's more to it than just extra cooling !
 
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