Power calculation question

[pothead here]

Hey. I have a 120v 1250w element, in a 20L boiler. It is too much power, and I can't afford a fancy controller right now, and I have wash that needs run. My question....I know that there is someway I can hook a lightbulb or two up in series in order to drop the power to the element. I am not very good with math. I want to be able to drop my temp a bit, but no too much. I don't know....is say 750w ok for a 20L boiler? I have a 1 1/2" x 18" tower without packing, and my element is just too hot.

[linw]

Hi, Pothead. Ligth bulbs aren't really going to cut it. The best method is to add another element into the boiler. This will alow you to get a lower power for your run. If you add a 1600W you can run it in series with the 1250W and you will get 701W. Another 1250W would give 625W. In parallel, you add the wattage for quick heat-up. But with 120V this would likely draw too much current. 1250W draws just over 10 amps. 1600W draws 13.2 amps. Both in parallel it comes to over 23 amps. High current is the penalty for having a low voltage.

But you could run one element for heat-up and hook them in series for the run.

I have a 1600W and 1700W in mine and use them in parallel (3300W) for heat-up and in series (824W) for the run. But we have 230V and a 20 amp breaker.

Hope this is some use.

[MyDBear]

Sorry pothead I dont know much about the heating element controls,but just a thought....wouldnt a dimmer switch work,it turns the power up and down to a light bulb,so it just might do the same for yer element,or use the control off a hot water tank they have temp. settings where ya can adjust the out put of yer element.but theese need to be on the tank or boiler because they have a temp. switch on the back of them that make them work. (just a thought)

[Grayson_Stewart]

wouldnt a dimmer switch work,it turns the power up and down to a light bulb,so it just might do the same for yer element

I purchased an industrial dimmer switch but ended up taking it back. It cost well over $100 for a light dimmer that could handle that kind of wattage and had a large disclaimer on the box stating it wasn't to be used on heating type elements. I was afraid it may have a melt down and I would have no recourse.

or use the control off a hot water tank they have temp. settings where ya can adjust the out put of yer element

I wouldn't think this would be a good idea. Seems that would cause surges in the vapor rather than a constant steady energy input.[/quote]

[MyDBear]

Thats why I use a gas burner