changing Stock tank heater from 120 to 240? Ask questions and find answers to many subjects relating to electrics and electrical work

[Akfjords]

Hi! I live in Alaska and have horses, thus need to have a tank heater for the water tank for the horses to keep water from freezing. The heater I have is a heavy duty cast aluminum ring, 1500 watts with a thermostat. It would seem that it could easily be rewired to operate on 240 V rather than 120 V and would be more efficient and lest costly operating on 240. Can you folks give me some advice on this? Would it possible to simply rewire the plug for 240 with ground and operate it on 240 volts?

Jean in Alaska

[sparx]

Hi Jean, don't think it's that easy as unless element is in 2 parallel halves which can be reconfigured into one series element you are stuck.
as for efficiency 1500W is same energy usage whatever voltage, just at twice volts half current so less losses in feed cable, or can use smaller cable-no other gains, eg1500W/240V=6.25A, 1500W/120V=12.5A.
If you try to put 240V across element as it is you will burn it out! it will try to pull 25A as element resistance will be too low[around 9.6Ohms i make it], sorry but not worth the risk also hope you run it through a GFI as horses, cattle, moose, ect have very low protection against earth faults so don't compromise 'Grounding'
sory not very much help,regards UK SPARX

[Akfjords]

Thanks, Sparx, I think I read something on that order on another website about changing a household water heater to 240. I won't fool with it! It is on a GFI, with an additional copper ground wire from the metal tank to a ground rod.

Jean in Alaska