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nesoutlook · 11-03-2014, 03:37 PM

I can't remember where I read this on the forum but disconnecting the ac plug for the refrigerator will reduce the battery drain since the inverter need not be running in order to run the refrigerator. Am I correct on this issue? If I am correct what other items can run with the inverter shut down? Just trying to get a better understanding of the electrical system for future boondocking adventures. My Airstream is a 2013 interstate ext on a 2012 MB Sprinter. Any help will be much appreciated.

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3 Dog Nite · 11-03-2014, 05:04 PM

This will reduce your 110 v AC power use from the converter. Its pretty much like unplugging your home kitchen fridge. But it is just a cooler then. It won't get any colder. The 12 v DC power your fridge uses is for the controls, not for cooling.

If you have an inverter, it will still use power with nothing plued into it. The best way to prevent inverter battery power drain is to unplug/pull fuse from inverter.

73shark · 11-03-2014, 05:43 PM

Not entirely true. The NovaKool frig operates on 12 VDC or 120 VAC. If the inverter is turned off (Since you have the Magnum inverter, I don't know if you can turn it off or shut the breaker off if there is one as 3 Dog Nite suggested. The TrippLite inverter on mine does have an Off switch.), it will run on 12V. If the inverter is on, it will run on 120 VAC which the frig reduces and rectifies to 12 VDC which does waste power. I think that was what you referring to regarding pulling the AC plug.

Boxster1971 · 11-03-2014, 05:45 PM

Sorry 3 Dog Night that's not correct. The refrigerator in a 2013 Interstate is all electric. The compressor and all control functions are 12v DC. The 110v AC plug on refrigerator is a useless alternative if powered by the inverter as it is wired on the 2013 Interstate. The refrigerator has a converter built in that changes the 110v AC to 12v DC when plugged into an AC source.

Most of us have just unplugged it from the 110v AC receptacle under the sink in galley and then run refrigerator solely on 12v DC.

- - Mike
2013 Lounge EXT on 2012 Sprinter

3 Dog Nite · 11-03-2014, 05:52 PM

OK, thanks for the new knowledge. It would be nice if my fridge ran on 12 v.

avanti · 11-03-2014, 05:54 PM

Yes. Running a NovaKool on 120VAC almost never makes sense. Running from 12VDC is the "native" mode of the compressor. If you use the 120VAC input when not plugged into shore power, you would be converting from 12VDC to 120VAC (using the coach inverter) and then immediately turning it back to 12VDC (using the NovaKool's built-in converter). If you ARE plugged into shore power, simply let your coach converter/charger make the 12VDC. The 120VAC input really makes little sense unless you are using the fridge at home.

PSchw · 11-03-2014, 06:52 PM

Great info. I know it runs on 12v or/and on 120v but did not know it would internally convert the 120v to 12v so having it plugged in on 120v makes no sense I unplug it tomorrow.
Thanks
Peter

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toskeysam · 11-04-2014, 07:25 PM

OK You guys have raised my curiosity level. I upgraded the Magnum controller supplied with my Interstate to the Magnum ME-RC50. It has on/off button on the main panel. I leave it off unless I have a specific need for it.
It does not come on when I disconnect from shore power with the refrigerator running....and as far as I can tell, the refrigerator keeps running. Hmmmmmm

toskeysam · 11-04-2014, 07:28 PM

let me clarify that last post. There are 2 on/off buttons on the ME-RC50. One for charge and one for the inverter. The inverter button is what I almost never turn on.

UKDUDE · 11-04-2014, 07:50 PM

On my 2014 - which came with the Magnum - I only ever turn on the inverter if I am unhooked and need to use the TV's or any of the sockets for anything requiring limited power (laptop for example).
The refrigerator will only come on when the 12V coach system is enabled.
Does yours work that way? Otherwise I wonder if it wasn't wired according to Airsteam's standard.

73shark · 11-04-2014, 07:52 PM

Quote:

Originally Posted by toskeysam

It does not come on when I disconnect from shore power with the refrigerator running....and as far as I can tell, the refrigerator keeps running. Hmmmmmm

As it should. It'll run on 12V until it sees 120 VAC and then it uses that but converts it to 12 VDC.

I only turn the inverter on when the grand-kids want to watch TV or to charge various devices.

nesoutlook · 11-05-2014, 07:15 AM

So all functions work without the inverter accept the ac outlets. Is this correct?

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Protagonist · 11-05-2014, 07:35 AM

Quote:

Originally Posted by nesoutlook

So all functions work without the inverter accept the ac outlets. Is this correct?

Outlets, microwave, and air conditioner all require 120vAC. All of them work on shore power or on-board generator. Outlets work on inverter, but microwave and air conditioner do not.

vinstream · 11-05-2014, 08:20 AM

The Novakool is a great product, However the "auto sensor" that switches from 12volt to 110 volt should be a switch not a sensor. Not a good design for those who want to boondock. I would think there could be a way to disconnecting the sensor and hard wiring a switch in place. You could also hardwire the 110volt connection into the shore power only side of the breaker box in a sense by passing the inverter. If it was up to me I would think this would be the better way to wire the coach. I like the Airstream Interstates, but there does seam to be some problems with the way the wiring system work, or rather don't work.

By the way is there many out there using solar systems on these rigs?!

73shark · 11-05-2014, 08:38 AM

There are some who have had lewster add quite a bit of solar panel power to their rigs. My 50 watt panel keeps my coach batteries and chassis battery charged and can keep the refrigerator running as long as there's not two or more cloudy days in a row.

Protagonist · 11-05-2014, 08:42 AM

Quote:

Originally Posted by vinstream

The Novakool is a great product, However the "auto sensor" that switches from 12volt to 110 volt should be a switch not a sensor.

I used to have a problem with the way some things were done on the Interstate. Such as the fridge. Until I realized that the folks at Jackson Center are used to dealing with Dometic 12v/propane fridges, and not Nova Kool 12v/120v fridges. They see a power cord coming out the back, they figure it must have to be plugged in somewhere. Since the fridge will work in 12v mode regardless of power source, the easy way is to unplug the 120v cord, and cover the plug with one of those white plastic prong protectors that a lot of appliances are packaged with these days.

Quote:

By the way is there many out there using solar systems on these rigs?!

Not for camping. But since I live in an apartment when I'm not living in my Airstream, and there's no place to plug in shore power, I rely upon the solar panel to keep the house batteries charged. The panel doesn't even have to do a perfect job of it, just keep the batteries charged well enough that I still have enough power to start the generator once a month.

I never really considered an Airstream Interstate to be much of a boondocking vehicle, and the only times I expect to ever need to boondock in it is for the first night of a hurricane evacuation, or if I arrive at a WBCCI rally too late to be parked the same day and I have to spend the night in the "bullpen" until I can be parked in my campsite the next morning.

Honestly, if I really wanted to boondock, I'd still be a tent camper.

Boxster1971 · 11-05-2014, 09:41 AM

Quote:

Originally Posted by vinstream

......

By the way is there many out there using solar systems on these rigs?!

Yes there are a few of us on this forum that have made significant solar upgrades. I have 400 wats on top of my Interstate and it totally changes the utility of the van. Spent 5 days of dry camping in Denali NP this summer in rainy cloudy weather. Extra solar made it possible without running generator.

IIRC the 2010-2013 Interstates came with 50 watts of solar. It was an option on earlier models. Airstream upped that to 100 watts sometime in 2014. I think 200 watts is a minimum for these vans to be useful.

- - Mike
2013 Lounge EXT on 2012 Sprinter

UKDUDE · 11-05-2014, 09:49 AM

Quote:

Originally Posted by Boxster1971

I think 200 watts is a minimum for these vans to be useful.

Together with upgraded batteries, Mike?

avanti · 11-05-2014, 10:01 AM

Quote:

Originally Posted by Protagonist

They see a power cord coming out the back, they figure it must have to be plugged in somewhere.

That's probably about right. The real question is why they order the 120VAC option in the first place. The NovaKool in our GWV Legend is 12VDC only--no plug to cause confusion. Plus, SOMEBODY paid for the useless power brick and cord.

nesoutlook · 11-05-2014, 11:43 AM

Thanks for everyone's help. My understanding of the Interstate's electrical system has greatly improved. Next week I am having Lew install 3 100 watt solar panels, Lifeline Batteries and Magnum Inverter along with upgraded TV Booster. Does the Magnum inverter have a way of making sure the batteries don't go below 50% automatically? Also I am looking for a cellular signal booster. Maximum is coming out with one which will allow multiple devices be used anywhere within the vehicle. This is a huge improvement over the ones at Wilson if it works. Comments?

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