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Electric heating element conversion

Does anyone know how to convert an electric heating element (the wire coiled around ceramic type) to operate at 500 watts it runs at 1000 watts at present

9 answers
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Jul 16, 2009. 12:08 PMJayefuu says:
I'm not sure I fully understand the question, but I'll have a shot at it. If someone could confirm/deny what I say after it might help msw100.

watts is a measure of the power that the heating element dissipates as heat. Power = voltage x current. Since your voltage is fixed (110-120V US or 230-240V Europe) and the current varies depending on what the device draws, I don't think you CAN convert the element to draw less current. The current is only limited by your electricity supply and the fuse that you have in your fuse box. Generally (in the UK at least) a 13A fuse is ample for a 3KW heater, or that is what we advised when I sold swimming pools.

Why do you ask? What are you trying to do?
Jul 16, 2009. 12:27 PMlemonie says:
If you added a heavy-duty diode you would cut the current and with it the power. However, since the resistance of the wire varies with temperature, you wouldn't reduce it down quite as far as half.

L
Jul 16, 2009. 12:35 PMsteveastrouk says:
You shouldn't encourage people to pull net DC from the mains supply !
Jul 16, 2009. 1:23 PMlemonie says:
Is that a bad thing? L
Jul 16, 2009. 2:45 PMsteveastrouk says:
Yes, it causes nasty effects in transformers upstream, saturation effects that can distort the supply and increase losses - and it will make the utility cross with you. Steve
Jul 16, 2009. 11:43 PMlemonie says:
OK, that's a good explanation. But I suppose it would be of little consequence if applied to this one device? L
Jul 16, 2009. 7:31 PMbrokengun says:
I may be wrong here, but if you just add another element in series or some other resistive load it should limit the current to heating element. If you did out some calculations you could figure out how much resistance you would need to add. I would recommend starting by measuring the resistance of the heating element first. Of course as Lemonie pointed out, it will change as it heats up. So it would only be an approximation.
Jul 16, 2009. 12:40 PMsteveastrouk says:
You really need a burst firing module like this.
http://www.united-automation.com/_ProductDetail.phuse?PhuseAction=88A4lc2%2blm3KsE6JbXzSLzoP67Nptt8j9qG1VmkNmhaWkfdUf1g10tlkwgnLKN7a

These put whole cycles of electricity to the load - making no interference with anything else, basically it will be on half the time.
Jul 16, 2009. 12:29 PMlemonie says:
Of course a dimmer switch might be the answer?

L

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