Trying to understand - inverter?

[DutchmenSport]

New 5er, 2 weeks old. 2019 Montana High Country 375FL. I'm still trying to figure out how things work on it. Because of another thread, I decided to do some exploring and self-education on my inverter.

It's located in the pass-through under the front, attached to the ceiling of the compartment upside down. It's hard to see the ends. But I took photos of it and looked at the manual and finally figured out, by touch, where things are.

But here's the gipper, and what I don't understand. After trial and error this is what's happening.

According to the service guys at delivery, the only thing plugged into the inverter is the refrigerator.

So, why are there no lights or read outs on the inverter. Quite obvious after figuring it out, no battery power. The dealer showed me two battery cut off switches. He just pointed them out, didn't explain. Looks like one cut off is to the house, the other is to the inverter.

I flipped the switch and the inverter powered up! Yahoo! Problem solved! Well, not quite. Now I'm really confused about that refrigerator. What's really powering it?

So, step 1. I unplugged shore power and kept the battery cut off for the inverter off. Refrigerator was off.

Step 2. I left shore power unplugged and flipped the battery cut off back on. Refrigerator working, running. Yahoo! This works as expected.

Step 3. Plugged into shore power and left inverter cut off on. Refrigerator working! Yahoo!

Step 4. Plugged into shore power and turned inverter cut off, ON.
Refrigerator still running.

OK, so nothing changed with the refrigerator. It's apparent, when plugged into shore power the refrigerator is running on shore power. It also runs when not plugged into shore power, but receiving power from the battery via the inverter. Yet, I've done nothing with refrigerator, like switching outlets or anything.

So what gives? Is there a system built to detect when there is no shore power and the refrigerator plug knows to switch over to the inverter? That's the only thing I can figure.

I'm glad I figured it out, because up until now, the inverter has been turned off at the battery kill switch. That means the first couple trips we made, the refrigerator was actually off when we were traveling. Since we never opened the refrigerator door while in transit, I didn't catch it that the refrigerator was actually not running. At home, we're plugged into power all the time. So, would have never thought to check. I was just assuming the refrigerator ran off the inverter all the time, plugged into shore power or not?

Any insights here? If this is the way it's suppose to work, that's some pretty creative technology going on there! I love it. It means I won't be running off the battery except when actually in transit.

Thoughts anyone?

[wa8yxm]

There is a device called an Automatic Transfer Switch. Depending on your inverter it may be built in or it may be an independent box.

When you have shore power it "Switches over" to shore.

My old inverter.. had 2 off switches. ONE of them was on the inverter itself and if you turned it off. it was OFF. and I mean OFF no power passed that box.

Turn it on and you had a remote switch that "Disabled" the inverter (or charger module different switch) if that was OFF shore power lost things no longer worked. ON they ran off battery.

My NEW inverter has an on/off button. if you do not have shore power you can turn the inverter on and off with the button. IF you do have shore power the inverter turns itself on and if shore power is lost UPS mode it turns on and I mean faster than you can blink.

I still have one problem with the new inverter though. Will figure it out later.

[theczar]

Mine has as others have noted, a passthru for the 120V. The Fridge is plugged in to the inverter. There is a 120V feed into the inverter, when on shorepower that powers the Fridge regardless if the inverter is on. When 120v removed the switch determines if inverting or not.

[time2roll]

Make sure you turn it off and flip those switches off in storage or the battery will be dead in two days or less.

Basically while in use you just turn it all on, plug in at the destination and all is automatic.

Off-grid camping for more than a quick overnight stay will be a bit more effort.

[CincyGus]

I have the same setup. Whirlpool 11 CF fridge on an inverter. And they gave me a group 24 battery. I asked them how long that would support the fridge and they said about a day, inspiring my confidence that I won't have to run the genny both AM and PM!

Once I got it home, I called my golf cart guy and ordered 2 extra Trojan 1275 12v group 31 batteries and wired them in parallel. Had to trim one of the battery box lid overhangs where they give you room to run the cables out of the box but they both fit on the battery rack.

I haven't dry camped to test them yet but I'm thinking I should get 3 days or so now between Genny runs. Donated the group 24 to a buddy of mine that fishes as a new trolling motor battery.

[wa8yxm]

There are 2 x 2 (possibly 3) types of inverters. We won't discuss MSW/PSW since it does not apply here

The 2(Poss3) is a Stand alone inverter. This makes 120 volts out of 12 volts that's all it does NO other features. A bad choice and very likely not what you have....

2 and 3 have both AC in and AC out.. Inside the box is an automatic transfer switch. IF you have shore or Generator power the unit passes this through to the Fridge. if not. and if the inverter is enabled. it eats battery power to do the job.

3 has a charger as well. I do not know if yours does but from the "no lights" I suspect not

Optional.. type one feeding the SHORE input of a common transfer switch and SHORE or Generator feeds the GENERATOR input. that way if you plug in it auto switches to shore power. I would need to see your RV to be able to identify what you have

I have a "3" with the charger disabled (making it a "2") most of the time. Soon (next week) I'll be putting in a remote switch so I can turn the charger module on and off as needed (I have a different converter/charger I like the programming in better than what I can do on the Freedom XC or the Prosine it replaced and both are very programmable. )

[BFL13]

Even a plain inverter with no transfer switch would be ok. The fridge would be on the inverter on battery. The battery would be on converter on shore power. Just don't have the converter on the inverter.

[hedge]

May be a good reason to get some solar if you boondock at all without services so you can keep your fridge going... but I'm sure you've considered that.

I plan on getting a residential fridge for my camper if the other one dies. I have the solar all ready to go but I camp almost exclusively without services.

[DutchmenSport]

"But then again if you have a regular home style fridge then forget everything I just said, lol. "

Yes, it's a Samsung household all electric refrigerator. The only difference between the Montana High Country 374FL and the 375FL? The 374FL comes with an RV refrigerator - gas/electric. The 375FL comes with an all electric one. (and I suppose the inverter too).

[185EZ]

OK, I'll bite.
Your fridge will run on shore power
If there's no shore power it will run off inverter and mine will do it automatically.
But i don't want it to run off inverter since it will drain my batteries in a few hours.
I manually switch the fridge mode to propane and then i don't worry about it
But then again if you have a regular home style fridge then forget everything I just said, lol.

[Big_Katuna]

I would surprised if the inverter didn’t power some outlets.

[DutchmenSport]

MrWizard wrote:
Yes
There is a transfer switch
Could be internal to the inverter,
Or external at the fridge
How many wires are connected to the inverter?

Internal ts is called a pass thru switch
And would be the default setting when shore power or generator per is on

Yes, thank-you.
3 wires in to the inverter from the battery. One is a ground.

Looking at the diagrams in the manual, it shows a CSW-TS15 Transfer switch with power coming from the plug at the inverter, and another AC in and AC out line. It also shows an AC sub-panel (after the transfer switch), and then a line to the plug. I guess I'll be tracking down where these connections are. So looks like that transfer switch is external of the inverter.

Mystery solved! Thank-you so much!

This is absolutely GREAT! I'm liking this new 5er more and more all the time!

[MrWizard]

Yes
There is a transfer switch
Could be internal to the inverter,
Or external at the fridge
How many wires are connected to the inverter?

Internal ts is called a pass thru switch
And would be the default setting when shore power or generator per is on