Welder as a power controller for heating element?

[Jwolfrom80]

I built a bokakob and am trying to figure out a way to control the power to my 5500 Watt water heater element. I thought if I found a cheap used 240v arc welder I could hook the element up to the stick leads and adjust the power through the welder's power controller... What do you think?

[NcHooch]

the output of a welder isn't 240 VAC ....so i doubt you would get the power output you need for the heating element . I think you need a Mule Kicker 5000.
NChooch

[Jwolfrom80]

But does the heating element really care if its getting DC or AC? Shouldn't it heat up just the same?

[rad14701]

Sounds like overkill to me because most arc welders waste a lot of energy unless newer ones are more efficient than the older ones I've used... Phase angle controllers are about as efficient as you're gonna get due to the timing and low amount of energy required for the control circuitry...

[AKAAB]

I believe the cheaper welders, like the $99 Harbor Freight unit, have a limited duty cycle. The unit basically shuts down after about ten minutes or so in order to cool. Dialing down the output might buy you a few more minutes of run-time, but you'll never be able to achieve any real control.

[bullpeters]

A Variac would be the go, careful how you isolate/earth the whole thing. This is something I DO know about, my "heater inside the keg" unit scares the shit out of me. Steel, a doubtful earth and 240V? plus flammable liquid.A variac is about 80 bucks i think but it doesn't isolate you from the mains current load

[Ayay]

Look at the thickness of the leads (cables) of any welder, and then look at the thickness of the wire in the heater element. Cheap stick welders deal with around 45 to 200Amps, the stuff that melts metal. Your boiler won't need more than 15Amps. Tig welders can go down to 5amps, but they are not cheap and their solid-state circuitry can die in a blink for no reason even if you really know electronika.

Try out a cheap 2nd hand element on a cheap ol 2nd hand welder and see what happens. I think the element will pop as soon as you switch it on

[KY1792]

Plus the fact that welders only deliver low voltage which seldom exceed 50 volts, turning your 5500 watt element into a 240 watt slow cooker.

[Coaster]

@ Jwolfrom80,

Suggest reviewing the “Phase Angle Control modules” Forum thread in the New Distiller Reading Lounge sub-forum and other PSR-25 Phase Angle Control related Forum threads and consider making yourself a PSR-25 based phase angle controller to control your 5500-watt electric water heater element.

Regards,
Coaster

[rad14701]

A Lincoln 225 arc welder runs at ~79V and requires a 50A circuit... By dropping the voltage they can select a broader range of amperages with less fluctuation... But the amperage is sent out in a mercilessly brute force manner that would not be very controllable... While an element might be able handle the wattage there is no guarantee that it could handle the amperage...

Pick the right tool for the job... Go with Phase Angle Control...

[The Baker]

But does the heating element really care if its getting DC or AC? Shouldn't it heat up just the same?

My knowledge of things electrical is limited, but before you buy an element, READ THE SPECIFICATIONS!
On the box, on the web, on the specification sheet, stamped on the element, whatever.

If it is intended to run on alternating current it will be marked AC.
Direct Current , DC.
And if it doesn't care IT WILL ASSUREDLY BE MARKED AC/DC.

If you have to ask.....!!

[Jwolfrom80]

I have decided to go with a Mulekicker design for its affordability, size, and fine control. I cant even find a used welder big enough for my 5500 watt element as cheap as I can build a new Phase Angle Controller box. Plus it was just chalking up to be a bad idea for the lack of fine control, welders are big, it may not have even worked! Thanks for your help guys!

-Joe