low(er) wattage hot water heating elements?

[a-d-s]

The standard hot water heating element seems to be 1500W for small tanks. Does anyone know of lower wattage ones being available? Our trailer only has a 30 amp connection and I find in the hot summer with the AC on and the hot water cycling (and any other small loads) we trip the main sometimes. It's annoying and I am sure a smaller element would keep up to the modest demands just fine.

Not really a big deal, I am just curious.

[dclark1946]

smkettner wrote:
Half the voltage = half the amps. Resistance remains fairly constant.

Then do the volts x amps = watts. 25% is about right.

Or P=V²r

Dick

[ScottG]

Lynnmor wrote:
I plan on adding a 20 amp line in and use that for the water heater when available.

That's what I did and it makes all the difference!

[Lynnmor]

I plan on adding a 20 amp line in and use that for the water heater when available.

[ScottG]

smkettner wrote:
Half the voltage = half the amps. Resistance remains fairly constant.

Then do the volts x amps = watts. 25% is about right.

I see my problem, besides doing it in my head, I was not deviding both values and maintaining the wrong constant.
It's been too long since I used this stuff I guess!

Thanks,
Scott

[time2roll]

Half the voltage = half the amps. Resistance remains fairly constant.

Then do the volts x amps = watts. 25% is about right.

[ScottG]

Chris Bryant wrote:
A 240 volt element will draw 1/4 of its rated wattage at 120 volts, so a 240 volt 2000 watt element would draw 500 watts, and a 240 volt 1500 watt element would draw under 400.

The math there has me stumped.
Wouldn't a 240V element run exactly half the wattage at half (120V) the voltage?
Or are they non-linear because of the resistance change do to heating of the element or something?

[a-d-s]

Thanks all. Good call on the 240v element, just ordered a 2000 watt one up off Amazon.

I could use propane, but it's nice when we're on full hookup for a couple weeks not to worry about propane.

[wildtoad]

The PO installed a Hot Rod kit on Atwood wh. Draws very little current, gets the water darn hot. I have no idea if the element will go into your wh.

[Iraqvet05]

12thgenusa wrote:
Just a suggestion, run the WH on propane when using the AC.

x2

[Chris_Bryant]

A 240 volt element will draw 1/4 of its rated wattage at 120 volts, so a 240 volt 2000 watt element would draw 500 watts, and a 240 volt 1500 watt element would draw under 400.

[greenrvgreen]

When I bought a 6 gallon residential water heater at Lowes, it had a 1650w element. I searched Amazon and found a 1000w element that appeared to be a replacement for an RV wh. It fit my resi wh fine and I'm sure it would fit an RV wh.

Going from 1650w to 1000w, the hot water regen from cold went from 30min to 40 min--not even a notceable time difference.

[time2roll]

One of the conversion kits might be adaptable.
I think Hott Rod is just 450 watts.

http://dg-usa.com/hott-rod/

[12thgenusa]

Just a suggestion, run the WH on propane when using the AC.