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Protagonist · 11-13-2013, 10:33 AM

Quote:

Originally Posted by weirdstuff

Just reading something on this other thread...

Am I supposed to turn off my fridge on my 2014 Interstate when I refuel at the gas station?

Someone mentioned this, but I don't know if that just applies to older models, or to the newer ones as well.

No. Your fridge doesn't have a pilot light or spark igniter because it doesn't run on propane, and won't ignite fuel vapors. But if you're running your water heater or furnace, turn them off when you refuel.

weirdstuff · 11-13-2013, 10:40 AM

OK guys, thanks. Fridge is 12v/120...no propane. Good...one less thing to worry about blowing up.

wayneskid · 11-13-2013, 11:46 AM

Weirdstuff,

It sounds like you are getting there! The systems in these rigs are complex and you will be learning forever! For me, that's part of the fun of ownership. The main things I would tell you:

This forum is your friend! There are a lot of really knowledgeable, helpful folks here. But, keep in mind that there IS misinformation here too. So, you have to do some sifting.
As AS Interstates have evolved over time there have been many changes, even within the same AS model year. So what may be true for any one owner may or may not be true for your van.
For the Sprinter bits, the Sprinter-Forum is excellent!
The book "RV Electrical Systems, A Basic Guide............." by Moeller is good even if a little dated. It will help you get your head around the basic concepts. $18 at Amazon.
If you haven't already, get a decent digital multimeter and learn how to use it. At least the basic functions.
Deeply discharging a lead-acid battery, even one time, is very detrimental to it's life and capacity. The damage can be essentially permanent. The common recommendation is that you should never discharge a battery below 50% capacity. Some manufacturers (Trojan for one) suggest you never discharge below 80%.
Understand and use your battery monitor. If you don't have one in your Interstate, get one. I like the Trimetric by Bogart Eng. A good monitor actually keeps track of current in and current out of the battery bank. This gives a much more accurate picture of your battery SOC (State of Charge) than you will ever get from voltage readings.

Good luck! Enjoy the learning!!
Wayne

David M · 11-13-2013, 12:27 PM

Quote:

Originally Posted by weirdstuff

OK guys, thanks. Fridge is 12v/120...no propane. Good...one less thing to worry about blowing up.

I unplugged the 110v on my fridge so that it always operates on 12v. This is easy to do if you don't have a Wardrobe version. You simply open the tilt-out tray under the sink, reach in and unplug it. (I have a 2013 Interstate Ext with the Tripp-Lite Inverter). I also turn on the inverter only when I want to watch TV (I don't know how Interstates equipped with Magnum inverters operates, however). Have fun!
David

Boxster1971 · 11-13-2013, 02:57 PM

You can get some basic info on RV electrics from this sites six online seminars:

RV Electrical Systems - Class

73shark · 11-13-2013, 04:12 PM

Quote:

Originally Posted by David M

I unplugged the 110v on my fridge so that it always operates on 12v. This is easy to do if you don't have a Wardrobe version. You simply open the tilt-out tray under the sink, reach in and unplug it. (I have a 2013 Interstate Ext with the Tripp-Lite Inverter). I also turn on the inverter only when I want to watch TV (I don't know how Interstates equipped with Magnum inverters operates, however). Have fun!
David

So basically if you're plugged into shore power, the inverter is converting that to 12 volts DC to charge the batteries that are running the refrigerator. That should work but it does put more charge/discharge cycles on your batteries.

David M · 11-13-2013, 04:45 PM

Quote:

Originally Posted by 73shark

So basically if you're plugged into shore power, the inverter is converting that to 12 volts DC to charge the batteries that are running the refrigerator. That should work but it does put more charge/discharge cycles on your batteries.

I upgraded my solar panels to 200w, so I rarely plug into shore power anymore (I actually plugged it in for one night in the last few months just because I was parked right next to an outlet). Also, I run my fridge 24/7 because my Interstate is a daily driver and I like to have cold water anytime I want. And when I do turn on the inverter to watch TV, I don't run down my batteries even further by the inefficiency of the inverter converting 12v to 120v just to have the fridge convert it back to 12v. Well, that's the theory anyway

David

weirdstuff · 11-13-2013, 05:14 PM

David, If you have 200w solar panels, don't they just store/convert the power into the 12v battery? If that's the case, then aren't you just limited by the 12v battery capacity?

wayneskid · 11-13-2013, 05:31 PM

Quote:

Originally Posted by 73shark

So basically if you're plugged into shore power, the inverter is converting that to 12 volts DC to charge the batteries that are running the refrigerator. That should work but it does put more charge/discharge cycles on your batteries.

Inverters convert DC to AC, not the other way around. In our Interstates, 12VDC from the battery bank is "inverted" to 120 VAC.

wayneskid · 11-13-2013, 05:41 PM

Quote:

Originally Posted by weirdstuff

David, If you have 200w solar panels, don't they just store/convert the power into the 12v battery? If that's the case, then aren't you just limited by the 12v battery capacity?

Given sufficient time, good sunlight and a quality charge controller, a 200w solar setup will fully charge a pretty hefty bank of house batteries. For example, the setup I'm considering would have 300Ah of capacity. This should be enough for a few days of careful and selective use of the most important electrical consumers.

73shark · 11-13-2013, 07:03 PM

The TrippLite converts 120 VAC to 12 VDC to charge the batteries. It also "inverts" 12 VDC to 120 VAC to run the TVs, etc. I least that the way I think it all works.

wayneskid · 11-13-2013, 07:26 PM

Quote:

Originally Posted by 73shark

The TrippLite converts 120 VAC to 12 VDC to charge the batteries. It also "inverts" 12 VDC to 120 VAC to run the TVs, etc. I least that the way I think it all works.

Correct, except wierdstuff has a 2014 which I think has a Magnum charger/inverter. They probably function pretty much the same way. If you have a source of AC (shore power or gen running) the charger/inverter will generate 12VDC to charge the batteries. If you have no source of AC, the inverter will draw from the battery bank and generate 120 VAC.

weirdstuff · 11-14-2013, 10:24 PM

Yes, I have 2014, with Magnum Inverter/charger.

AstroDave · 11-15-2013, 04:57 PM

Hi folks,

I'm new to the forums and am just contemplating getting an AI. First let me congratulate you all on excellent forum topics and responses. They will be extremely helpful if I manage to get into any RV.

I've noticed from this thread that there is considerable confusion at first when new owners get their vehicle. I've tried to distill my understanding of what is happening (at the logical power flow level) in the vehicle.

I'll be interested in reactions to my chart, especially additional devices I've forgotten, and more importantly any logical errors I've made. I'd also like to fill out a list of culprits for overnight battery drains that one must be careful to turn off or unplug.

Thanks for any more detail you can add while still keeping the diagram at a logical level. For example, which switches should be turned off/on when stored.

Of course, as a newcomer I may have missed a similar diagram earlier, or perhaps some manual has one I could use instead. If so, I apologize.

73shark · 11-15-2013, 06:23 PM

Welcome to the forum.

Looks good. BTW, the generator is good for 20 amps. Awning (may be on chassis battery), bathroom exhaust fan, & antenna amp are missing. Water heater is also on the hi-current buss. Not sure if the lo-amp buss is also fed by the shore power buss.

Did you intend to leave out the main battery disconnect switch? I honestly don't know what bypasses it but think the lounge recliner does.

Protaganist is pretty fluent on all of this so will probably have some ideas.

PS: I think Gerald posted a diagram over on the Yahoo forum.

weirdstuff · 11-15-2013, 08:47 PM

AstroDave...that's super helpful. Thanks so much.

At first I looked at it and thought it was a joke, as it looks so complicated!! But now I get it!!

Now, a couple more questions (really, you didn't think I was over this, did you?)...

1. So, when Fiona is stored, whether for just a few days, or a week, or longer, I should turn off my inverter, correct? Otherwise it's a slow drain on the 12vdc.

2. If I'm dry camping and not running my TV, DVD, lights, or have anything plugged in, I can/should also turn off the inverter to save my 12v?

3. Husband told me that yes, the heater runs off of LPG, but that we have to have the inverter on to convert the 12v to 110v because that's how the fan for the heater runs. I don't see this connection on your chart. Anyone confirm or deny this?

4. Your chart shows a converter and a charge controller. I think these two steps happen automatically on Fiona, with no action by me at all. Anyone confirm or deny this?

I'm gonna copy this and laminate it and carry with us at all times. Brilliant!

weirdstuff · 11-15-2013, 09:01 PM

We went to our indoor storage facility to pick up Fiona today. She's been stored since Monday evening. I'm in San Diego, so, nights are chilly, but not drastically cold.

Before we turned the engine on, I went to check the battery charge and tank levels. The inverter is flashing a "Fault, Lo Battery" warning.

We turned on the engine, and the warning light went away, and the battery level is showing 100% charge.

As far as I could tell, we had turned off all power sources in her, except for, perhaps, the inverter, because we didn't understand what to do with the inverter until just yesterday.

By the way, our inverter seems to have only ON, or OFF. There is no "Charge Only" or "Standby" setting, as some of you mentioned. At least that's what it looks like to us.

Why am I getting this Lo Battery warning? I must be missing some part of this puzzle.

73shark · 11-15-2013, 09:05 PM

You might want to hold off on the lamination process. As an recovering engineer, I can tell you that there will be further revisions to this document.

weirdstuff · 11-15-2013, 09:25 PM

Quote:

Originally Posted by 73shark

You might want to hold off on the lamination process. As an recovering engineer, I can tell you that there will be further revisions to this document.

OK. I'll hold off on it. In the mean time, I'm thinking about enrolling in grad school to get an electrical engineering degree.

Protagonist · 11-15-2013, 09:27 PM

Couple of things not shown on the diagram… The retractable step and the power awning are both run off the chassis battery, not the house batteries. Ditto for the alarms that tell you either one is extended with the engine running.

On the diagram, I don't see the Battery Isolation Module, that connects the chassis and house systems, or disconnects them when one is depleted, in order to save the other. On mine, the BIM itself draws its power from the house system. Which means that if the house system is too depleted, the BIM won't have enough power to reconnect the two systems to let the house system charge off the alternator. BIM should be powered off the chassis battery to prevent that glitch, and I think on newer models it is.

Also not shown on the diagram, but every single display on the control panel is powered off the house batteries. If it has a light or a digital readout, it uses power. Not all of them are necessarily shut off by the main disconnect.

The wall-mounted air conditioner/furnace thermostat uses 12vDC, even though the air conditioner itself is 120vAC.

The LPG detector is hard-wired to the 12v house system as well. I can't remember if it draws power 24/7/365 or if it can be shut off from the house battery disconnect switch. I think it is controlled by the disconnect, because the owner's manual says to shut off power to it to reset it in case of a fault. I actually did that once when it gave me a fault reading after I accidentally kicked it, and it worked.

Quote:

Originally Posted by weirdstuff

1. So, when Fiona is stored, whether for just a few days, or a week, or longer, I should turn off my inverter, correct? Otherwise it's a slow drain on the 12vdc.

I turn mine off. The solar panel doesn't need it to charge the batteries. Even if you leave it in "charge only" mode, it's still a drain on the house batteries because it will still need power for the cooling fan. Fully off is best.

Quote:

2. If I'm dry camping and not running my TV, DVD, lights, or have anything plugged in, I can/should also turn off the inverter to save my 12v?

Again, I turn mine off unless I need it to power an appliance. Turning off all of the breakers does not turn off the inverter, because the inverter uses 12vDC power. If you run your generator on a regular schedule to charge up the house system (have to do it while you still have enough juice to start the generator, though) then it doesn't matter if you turn the inverter off or not, and in fact it needs to be on for the generator to charge the batteries.

Quote:

3. Husband told me that yes, the heater runs off of LPG, but that we have to have the inverter on to convert the 12v to 110v because that's how the fan for the heater runs. I don't see this connection on your chart. Anyone confirm or deny this?

Thermostat is 12vDC as noted above, and I think— but I'm not sure— that the furnace fan motor is 120vAC same as the fan motor on the air conditioner, else a single switch on the thermostat panel couldn't control both.

Quote:

4. Your chart shows a converter and a charge controller. I think these two steps happen automatically on Fiona, with no action by me at all. Anyone confirm or deny this?

Charge controller for the solar panel is fully automatic. There is nothing for you to set or adjust. However, the charge controller draws its power from the house batteries, NOT from the solar panel itself. Which leads to the catch-22 that when your batteries are too far depleted, the solar panel won't charge them because there's not enough juice left to run the charge controller even if the solar panel is getting plenty of sun.

Converter is just the "charge" setting on the inverter/charger. If you have the inverter set to "charge only" then the converter is running. If you have the inverter set to "auto" and you hook up an outside source of 120vAC, the inverter automatically switches over to charge mode as well. The only time you would need the "charge only" setting is when you want to make sure that the batteries are charging but the 120vAC power isn't going to any of the appliances, such as when you're plugged into a 15amp power source to recharge and there isn't enough amperage to go around.

My inverter/charger is a Tripplite. Someone else will have to chime in on the intricacies of the Magnum inverter/chargers used on newer models.

The Energy Management System (EMS) that automatically sheds loads when they exceed the available amperage gives a lower priority to battery charging than just about anything else, so the inverter's "charge only" setting allows you to bypass the EMS to charge the batteries from a low-amperage source.