Dometic Power Consumption

[SteveJ]

Originally Posted by peteco

Steve J,
Does this come with the temperature sensor?

Yes, and IIRC, it's water proof.

[SteveJ]

The Inkbird is one of the controllers that I have heard of being used to put electronic control on the compressor frigs, also. Most have had good luck with them in those applications.

We only used ours for about 5 months as we sold the Roadtrek. I had set the hysterias for two degrees and the temp at 34. It would kick in at 36 and out at 32, verified by a wireless thermometer.

I have a very similar 12v unit on the control system I built for our HRV ventilator in our house to replace the garbage touch screen version the manufacturer provided that failed every few weeks. I am using on a defrost circuit in the HRV. I do wonder a bit about the <3 watt power use spec, though, (ours is 2W) as they have a fairly large LED three number display on 24/7 with no way to time it out. I have not measured our use on the HRV because it runs on the HRV power supply so is essentially on house power. But even 3 watts is about 6ah per day. The other essentials running like detectors and monitors I put at 10ah earlier in a post may or may not be high depending on what you have, so still 15ah or so before you actually use any for other things.

I can't remember the exact draw of this thermostat but I think it was less that 2 watts and way down in the milliamp range when the internal relay was not engaged. Bonus was that the 3-4 watts that the fridge board would draw if not cooling was eliminated. A loos in hot weather, a gain in cool weather.

I didn't get the Inkbird to save power. I bought it cuz I got real tired of having to babysit the Dometic due to crappy temperature control. It worked perfectly for that.

Does your 20-25ah per day use include the solar running and supplying some power? Solar can really mess up trying to find out how much power you really use because the solar controller output totalizers are often not very accurate and don't take into account charge efficiency, and the normal battery monitor subtracts off what goes back into the battery or is used in the van from you daily AH gain. The power that goes back in or is used in the van is lost from the monitor, also.

The AH figures are from a shunt based pair of one way coulometers. One measured charge, the other discharge. The 20-25AH would be with no solar contribution, actual use for a day. When stopped somewhere for just two overnights I wouldn't bother deploying the portable solar.

There is one thing about the power use in the gas frigs these days that is good compared to a compressor frig, and it is that a gas frig usage doesn't vary nearly as much with run time and temperatures when compared to a compressor frig, so the gas frig is easier to estimate total use for figuring out power needs.

All that said, if our current Dometic DM2862 goes kaput it will be replaced by a 12 volt fridge.

All that said that whole system worked well for us, as does out current setup on the Safari Trek.

PS. Are the lakes up there frozen over yet?

[peteco]

Originally Posted by SteveJ

I didn't get the Inkbird to save power. I bought it cuz I got real tired of having to babysit the Dometic due to crappy temperature control. It worked perfectly for that.

That's why I would want it for my new Dometic RM2554, as the temperature control is very flaky.

[hbn7hj]

I just turned on the 2354 refrigerator. The total amp draw with flame burning is .25 amps. That is 250 milliamps. It is dark out so no solar. I am surprised. Will do further tests tomorrow to verify. Seems a bit low but I can’t find an error.

[SteveJ]

Originally Posted by peteco

That's why I would want it for my new Dometic RM2554, as the temperature control is very flaky.

I mounted ours tied to the bottom of a shelf in the middle somewhere, using zip ties. The main casing has openings for ventilation that can/will let licquids into it. Not a good thing. I covered the top with a freezer storage bag and let the ends hang over the sides. I brought the wiring through the drain tube, slitting a small hole in it on the top side of the tubing near the fridge. I used a bit of caulk to seal it.

Once the head scratching is done it is less than a one beer/glass of wine/soda/water/tea job.

Before installing this we had to either shut the fridge off for an hour or three and hopefully not forget to turn it back on or open the door for 10 to 15 minutes to get it above freezing. The only "thermistor adjusters" that I could find were for dealing with temperatures that were too warm, hence the Inkbird. A lot of mental relaxation for only $16.

HTH.

[hbn7hj]

Originally Posted by hbn7hj

I just turned on the 2354 refrigerator. The total amp draw with flame burning is .25 amps. That is 250 milliamps. It is dark out so no solar. I am surprised. Will do further tests tomorrow to verify. Seems a bit low but I can’t find an error.

Looks like a correct number, .25 amps with burner on. Anyone else able to verify?

[bwatters60]

Originally Posted by GallenH

I've been toying for some time with replacing my Dometic 2310 3-way fridge with something.......it's begining to not respond to the thermostat control and doesn't seem to make a difference if it's on max or min temp. So the logical 3-way replacement seems to be the 2354 which is the same size.

BUT, from what I can understand from on-line comments, it takes 1.3A constantly just to run the circuit board. If that's the case, it seems like a small jump to a compressor fridge of similar size which appears to be using 2.2A when running.........and it wouldn't run all the time.

Does anyone know if my stats on the 2354 are accurate?

If so, I'd have to increase my battery capacity either way.

Thanks in advance
Glenn

FWIW - When studying the feasibility of replacing our RM2554 with a NovaKool AC/DC, I did a lot of electrical analysis. Our RM2554 in propane mode drew 0.52 amps.

[themexicandoctor]

I don't know if your stats are accurate but I have a Novakool R3800 & I love it!

Overnight I use about 24 amp hours - 30 with everything connected including the fridge.

When I say overnight that night mean not driving after 5pm where there is very little sunlight hitting the solar panels until 8am or driving for a few hours per day before 11pm.

I chose the R3800 at 2.2 amps versus the R4500 at 4.4 amps, I would have preferred the larger unit but like all RV Choices, one compromises & works around the challenge.

It's a joy not to have to be concerned with parking the unit level.

And knowing the food is always going to be safe.