Xantrex/Heart Freedom 25 -- How to connect Water Heater

Bene505 · #1 10-19-2010

I'd like to have my hot water heater only heating under 2 circumstances: 1) the boat is connected to shore power or 2) as a dump load for the wind generator, when the batteries have reached a preset voltage.

This is what I'm thinking. Can anyone here add some insight to this?

The relay is something I'll put together that is normally open connecting the dump load controll, but when shore power is connected it will close to allow shore power to connect to the hot water heater.

I am not planning to get a 12v element for the hot water heater. I will have some loss when the wind is heating my water, but it will mean that I'll have the flexibility of connecting to shore power (oftern in winter/spring, extremely rare in summer/fall).

Circuit breakers are not shown. I need to look at the existing box and see if I can rewire just the breaker for the hot water heater, to disconnect it from the normal input and connect it to the relay. Or I may need a separate box altogether for the hotwater heater -- or use a fuse maybe to save room.

The normal input for the circuit breakers will now be connected to the inverter/charger instead of shore power.

The dump load controller will be a Xantrex C60 (which I already own) or a Flexcharge. I don't know if the Flexcharge or the C60 will NOT open and close rapidly as the voltage hovers around the preset voltage or if they will have some hysteresis and open/close more gracefully. I'll have to see how that goes.

Any thought on this?

Regards,
Brad

sailingdog · #2 10-19-2010

Just curious, how would you be stepping the voltage from the dump controller up to the 110 VAC needed by the water heater, since you're not getting a 12 VDC element for it. I don't see an inverter in the diagram that would be connected to the dump controller.

Bene505 · #3 10-19-2010

Quote:

Originally Posted by sailingdog

Just curious, how would you be stepping the voltage from the dump controller up to the 110 VAC needed by the water heater, since you're not getting a 12 VDC element for it. I don't see an inverter in the diagram that would be connected to the dump controller.

Good question!

I'll use the dump controller to activate a relay that connects the water heater to the "other" 110v output that currently deadends in the picture.

Regards,
Brad

sailingdog · #4 10-19-2010

Then where is all the electricity that is being dumped by the dump controller going??? If you're not putting that through the inverter, what are you doing with it?

Stu Jackson · #5 10-20-2010

Why complicate things? This seems to imply that you will be leaving the inverter function ON all the time, right? Or else the relay wouldn't work. If you are intending to do this when you are away from the boat, then shorepower would either be available, making it moot, or you'd be disconnected from shorepower and want to dump the wind power, but there'd be no need for hot water 'cuz you wouldn't be there.

If you are on board, then it's simpler to simply turn on the heater when your conditions are met.

How are you controlling the inverter function of the Freedom? Link 2000? Remote panel?

The heater element only usually needs about 15 minutes or so to warm up 6 gallons. If you have an 11 gallon heater, maybe half an hour. We never leave ours on beyond that time, and only turn it on again when the hot water runs out when power is available. I've used our Freedom 15 inverter function to run the heater element, but only with the engine running. Only done this twice, since we change our showering and hot water habits to only after engine running, thus negating the need for electricity for hot water. Too many people leave their hot water heaters plugged in all the time.

What you'll find is that you'll draw down the voltage of the house bank so much by using the inverter function to heat the water that I'd bet the relay would start chattering, at best, or only open for such a short period of time as to make the automatic feature somewhat useless.

I would recommend a manual operation. I'd also try it out manually first to see what happens and to see if I'm anywhere close in my evaluation.

Interesting concept though.

deniseO30 · #6 10-20-2010

And they tell me I think too much! How bout you get or build a small solar hot water collector and just use a small 12 volt circulator? I can't imagine the amp load for a 12v element!

mitiempo · #7 10-20-2010

12 volt water heater elements here Water Heater Elements
in 300 and 600 watt sizes (25 and 50 amp approx)

remetau · #8 10-20-2010

I agree with others, why complicate this?

Connect the water heater to a breaker on the AC panel. You can turn it on when on shore. We never ran it from an inverter, it would draw too much, but we did run it using a Honda generator.

Install a 12v heating element. If your water heater has only one element, then you can get a new element that has 110v and 12v connections on it.

I prefer the Flexcharge over the C60 since it dumps the load directly from the wind turbine instead of the batteries.

Bene505 · #9 10-20-2010

Quote:

Originally Posted by remetau

I agree with others, why complicate this?

Connect the water heater to a breaker on the AC panel. You can turn it on when on shore. We never ran it from an inverter, it would draw too much, but we did run it using a Honda generator.

Install a 12v heating element. If your water heater has only one element, then you can get a new element that has 110v and 12v connections on it.

I prefer the Flexcharge over the C60 since it dumps the load directly from the wind turbine instead of the batteries.

Both 110v and 12v connections on the same heater element? Nice. I may have to look into it.

We spend the summer on the hook, usually at the beach all day. It would be great to have hot water when we return. But only as a dump load for the wind generator. I have no desire to run down the batteries heating hot water. Where were are, the average wind in July and August is something like 10 or 12 knots.

Note that the water will heat up eventually (especially if we just ran the engine, which would make the batteries more charged too) and I'll still need another dump load. That second dump load will be a more standard type (heater or fans, probably both). I left that out of the diagram to make the conversation here a little easier.

Thanks for the insights. More diagrams coming...

Regards,
Brad

remetau · #10 10-20-2010

Quote:

Originally Posted by Bene505

Both 110v and 12v connections on the same heater element? Nice. I may have to look into it.

Check here: SVHotwire Landing Page

Quote:

Originally Posted by Bene505

We spend the summer on the hook, usually at the beach all day. It would be great to have hot water when we return. But only as a dump load for the wind generator. I have no desire to run down the batteries heating hot water. Where were are, the average wind in July and August is something like 10 or 12 knots.

We no longer use an electric water heater, but when we did, we never had hot water from a wind gen diversion load. It may slightly warm it, but it just isn't that much power. Plus, if your batteries need charged at all, then the diversion doesn't even kick in.

Quote:

Originally Posted by Bene505

Note that the water will heat up eventually (especially if we just ran the engine, which would make the batteries more charged too) and I'll still need another dump load. That second dump load will be a more standard type (heater or fans, probably both). I left that out of the diagram to make the conversation here a little easier.

What is the other dump load for?

With the electric water heater, we found that the best way to heat water away from shore was to use the engine. The water heater we had used the water from the engine to heat the potable water.