On Wed, 5 Jul 2006 08:06:44 -0400, Kyler Laird
wrote:

writes:

Were I to
decide to go this route I would find some sort
of a DC heating element

What kind of heating element *doesn't* work on DC?

--kyler

Obviously, any resistive load will heat up if you put DC voltage to it.

But now you've got me thinking.

What are the design considerations for converting a heating element that
has been designed to function on 120VAC to 12VDC?

For example, I have a TANIS system in my a/c which draws about 375W @
120VAC.

It consists of four heated intake bolts, and a heated oil screen. It works
very well and heats the entire engine to 75-100°F on below zero F days
(with a cover).

I'd guess, as a minimum, I'd have to rewire everything to handle ten times
the current, depending on whether or not the 120V wiring is oversized, or
not. That might (or might not) add sufficient weight to have to do a new
W&B (A&P and logbook entry required). Obviously have to change the
connectors, too. How simple would it be to attach the larger wire to the
bolts and engine oil screen?

Will the heating elements handle a continuous (DC) as opposed to an
intermittent (AC) current? Or will I need some kind of
controller/thermostat?

I'd also want to retain the ability to run on AC, so I'd need some kind of
additional connector -- probably paralleled with the AC connector.

What about the AC neutral/ground? If that gets upset in the rewiring, I'll
wind up blowing GFCI breakers when I use AC.

??
Ron (EPM) (N5843Q, Mooney M20E) (CP, ASEL, ASES, IA)