Best circuit to tie in electric water heater

[Thorasaurus]

Hi there,

Our 1994 Excella Classic came with a gas-only water heater. I've installed a newer gas/electric Atwood model, but now I'm wondering where the best place is to connect the electrical. It's a 30 amp trailer.

Do you think I should:

a) tie into the same circuit as the microwave and try not to run the microwave while the water heater is heating

OR

b) tie into the receptacles circuit and not run a space heater or tea kettle while the water heating is heating

OR

c) something else (including not connecting it to the electric, though that would be a bummer)

[GCinSC2]

Have you looked at the various AC wiring diagrams for your trailer?

My 2007 has a dedicated 15A breaker marked water heater. What wattage is your new heater and does the water heater manual have any wiring requirements?

Gary

[dznf0g]

I would look into running a dedicated circuit. It may not be as hard as it sounds. I don't know your layout, but on my rear bedroom the breaker box is overhead in the rear. My water heater circuit runs from there down to the floor and then runs along the floor in a carpeted "chase" to the bathroom and there is the water heater. Point is, not all circuits run between the inner and outer skin and a bit of disassembly gets you there

[Thorasaurus]

Originally Posted by GCinSC2

Have you looked at the various AC wiring diagrams for your trailer?

My 2007 has a dedicated 15A breaker marked water heater. What wattage is your new heater and does the water heater manual have any wiring requirements?

Gary

It would use 13.5 amps when heating. I don't have the original water heater diagram but I should definitely check out the trailer diagram.

[Thorasaurus]

Originally Posted by dznf0g

I would look into running a dedicated circuit. It may not be as hard as it sounds. I don't know your layout, but on my rear bedroom the breaker box is overhead in the rear. My water heater circuit runs from there down to the floor and then runs along the floor in a carpeted "chase" to the bathroom and there is the water heater. Point is, not all circuits run between the inner and outer skin and a bit of disassembly gets you there

Yeah, mine run from the overhead compartment through the skin to the floor and I don't know how hard it will be to get it through the skin. I guess my thinking is that if the maximum is 30 amp for the trailer then having a dedicated circuit wouldn't really change much because it would still blow one of the breakers if everything kicked on at once, but maybe I'm not thinking about that correctly.

[dznf0g]

Originally Posted by Thorasaurus

Yeah, mine run from the overhead compartment through the skin to the floor and I don't know how hard it will be to get it through the skin. I guess my thinking is that if the maximum is 30 amp for the trailer then having a dedicated circuit wouldn't really change much because it would still blow one of the breakers if everything kicked on at once, but maybe I'm not thinking about that correctly.

True, but I'll still bet that run down to the floor in back can be fished pretty easily. There's no inner skin nor ribs in the top of the clamshell....but there may be some skin, and definitely a horizontal rib at the beltline. My trailer has an access compartment on that side of the trunk...where the wiring all comes down from above.
Might be worth a try.

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[dznf0g]

Your idea of using the microwave circuit would work. My old Prowler had just that setup....but....a switch was in the circuit which forced me to chose one or the other. Idiot proof.

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[richard5933]

Motor homes of the era had a small transfer switch to choose between a few devices, such as water heater, a/c, etc.

Assuming your 1994 is set up like mine, you could easily put a small manual transfer switch in the overhead cabinet with the breakers, and then run a line down to the water heater under the bed.

I'd use the breaker feeding the microwave like you suggest, having it go to the new transfer switch and then on to both.

Probably not room in the breaker panel for another breaker, but if there is you could go that route instead.

[Thorasaurus]

Thanks all! I think I will look to add a junction box under the rear bunk and tie into the microwave circuit. It does already have the switch to prioritize either microwave or A/C but this would come before that switch. Either way, shouldn't matter; just need to try to not run the Microwave while the water heater is heating.

Appreciate the brainstorming! Happy camping!