Propane Generator on 5th wheel (Auto-changeover)

[jbjlock26]

I am sharing this to hopefully help others, as I have struggled to find information and have finally gotten to the bottom of my problem.

I have a 2012 Montana with the normal propane installation, common to so many TT and 5th wheels; two 30 lb. LP bottles with an auto-changeover regulator and a secondary regulator mounted on the opposite side of the rig. In my case, this secondary regulator is set to 30 PSI.

I was unable to keep my Onan 5500 LP generator running after it started. It would starve for fuel and die in about 10 seconds after starting. This occurred with only one LP bottle turned on, as is so frequently done. After much reading on the subject, I discovered that I had been using the two-bottle system incorrectly. Since the generator draws a significant fuel load when starting, the auto-changeover apparently begins to switch fuel sources moments after starting. With bottle #2 turned off, the generator will get no fuel.

This situation may affect other large draw items, such as the propane furnace under certain conditions.

The proper way to utilize the auto-changeover regulator as I now understand it is as follows:
1. Choose what will be your primary bottle (the one you want to deplete first).
2. Turn the lever on the regulator to point to that bottle, and then open it first.
3. Open the valve on the secondary bottle.

When the first bottle runs out, the indicator will show that it is empty, and the regulator will have already switched to the full bottle. You can then switch the lever to the bottle that is now in use, and the indicator will show green, (or the presence of fuel).

Note that switching the lever is not switching bottles, but is switching the side of the system being read from the fuel indicator.

I have found through experimentation that I can shut off the secondary bottle if I choose to do so, AFTER the generator is started and running under load. The best approach will likely be to simply check the indicator regularly to see whether the second bottle has come into use. None of this is a factor if not using a large-draw appliance.

To summarize, the bottle that is opened first becomes the primary bottle.

Hopefully this information will help others with trailers; a motorhome with a single, frame-mounted tank would not likely experience this type of problem.

[seahunter]

Thanks for the post. We have the Onan and have only used it once so far and it worked okay with just one valve open - but if I have a problem down the road this will be a good source to troubleshoot.

[camper4]

Thanks for the post. The Onans are gas hogs.

[bncinwv]

That is odd, we have the same Onan and I always run it with just the off side tank turned on. We have 40 pound tanks but I would not see where that would make a difference. On ours, I start to have problems if I leave both tanks open and it switches between tanks. I am thinking at some point of either eliminating or replacing the off-side regulator as has been discussed extensively in previous threads on the forum.
Bingo

[DQDick]

Thanks for the post. For some reason dealers usually fail to explain how that valve is designed to work when new trailers are sold and those of us who came from TT's or pop ups probably haven't seen one.