240 volt element at 120 volts?

[artbrau]

any reason i can't use a water heater element rated for 240 volts on a 120v line? I figure the element is just a highly resistant wire. it will get less hot with less juice but it will still work and won't burn out. The same should apply for a stove top element.

Am I missing something? Thanks.

 

[The Pol]

You are right, you CAN use a 240VAC element on a 120VAC line. Instead of TWO HOTS, you will have ONE HOT and ONE NEUTRAL going to the element.

You will net 1/4 of the wattage when you do this.

A 4000W 240VAC element will provide 1000W at 120VAC.

Many people do this in RIMS setups becuase you are basically making an ULWD element.

 

[jkarp]

It'll work but you'll only get 1/4 the wattage thanks to Ohm's law. Say you've got a 3000W 240V element:

240v^2 / 3000w = 19.2 ohms
120v^2 / 19.2 = 750w

 

[artbrau]

Good advice. Thanks. Yeah, I am using it in a Rims setup where the "boost" phase is gas fired so a low power element is suitable.