Russell defrost heater wiring help

[Rob@goldcoast]

Is it possible to use 240volt heaters wired in series with 480 volt supply voltage?

[walden]

As long as the heaters are similar, have the same wattage, yes.

[Rob@goldcoast]

Thank you for the help

[Rob@goldcoast]

Russell said it cant be done, but I think it can. Any one have any reason why I shoudnt try it, or does anyone have any other info on this subject that could reassure me?

[Brian_UK]

I think Walden is wrong, you could use the 240vac heaters connected to a 240vac supply split off your 480vac supply and that would be OK.

[jamcool]

Just a thought Rob ,on a 480 system one leg and earth would give u what? 277 I think, are u going to connect your 240 heater to one leg and earth? If so wont u be 30 volts over? or there abouts and your 240 heater is it live and neutral or is it 2 115v lines
Just thinking out aloud ,any takers

[Rob@goldcoast]

Yes from ground each leg will be 277vac I am guessing that two heaters wired in series single phased out between two legs would work

[Brian_UK]

Wired in series will still give you a 240v item connected to a 277v supply !

[Dan]

Hmmmm. If I had a 1,000 ohm heater and wired it up to 230 Volts, I would draw .23 amps and have a wattage of 52.9. If I wired 2 1,000 ohm heaters in series and wired them up to 460 Volts, I would have .23 amps and 105.8 watts. But if I wired the 2 heaters in parallel to 230 volts my amperage would double but my watts would be the same. I would think it is okay. Perhaps I am missing something regarding Ohm's law?

[Rob@goldcoast]

If 2 wired in series 2x240 would be 480?

[frank]

Is it possible to use 240volt heaters wired in series with 480 volt supply voltage?

Before we can determine the answer we need the wattage of the heaters

Using Ohms Law (W = V x A) and transposing (A = W / V)

Assuming each heater to be 1000W in series (2000W total and applying 240 volts to neutral we would get
(2000 / 240) = 8.33A FLC

Applying 480V to neutral you would get
(2000 / 480) = 4.16A FLC

If you are talking of 480V 2 phase then this is something different