48 volts into 240v appliance

On Sat, 7 Feb 2004 17:07:29 -0000 ray! wrote: | I wish to shed some 48 volts DC power | If I just direct it to a standard 240 volt AC fire | what happens?

Why did you say "fire"? Freudian slip?

The world is a very big place. In the UK they call a portable heater an "electric fire". At 48 V DC you 'd only dissipate, hmm, say 4% of the rated dissipation of the heater at 240V - which might be too little to be worth doing. A UK plug is fused at 13 A (someone correct me) which is 3120 W, so at 48 V the same resistance element would dissipate about 125 watts. I don't know about UK electric fires but over here our portable heaters have AC motors and fans which of course will not run on 48 V DC.

Bill

thanks sorry yes I am talking UK here the sort of electric heater I have in mind uses a long coiled element rather than a heater with a motor and fan which we call a fan heater over here

I am not particularly wanting to get a heater that works very well, I just want a simple way of losing the spare energy, without having to buy a 48volt appliance

ray

This reminds me of that British puppet comedy about Ronald Reagan. In the show, Nancy Reagan used the phrase "electric fire" when she was referring to all the junk that Ronald Reagan had in his bathtub. :-)

Speaking of British and American differences, a 120 volt heater could certainly dissipate more energy and create more heat at 48 volts. But is it were me, I think I would just use four 12 volt DC car heaters connected in series.

Robert

You won't hurt the fire, if it is simply the long coiled element (no fan or electronics or timer etc.) - but you will hurt the battery, if that is the source, unless you monitor the discharge and stop it before taking too much out. Discharging a battery too deeply can damage it. If indeed it is a battery you want to discharge, I would suggest you incorporate an automatic shut off circuit in the discharge path.