Onan Generator diagnostic results

[bncinwv]

Went back to the rig (in mini-storage lot) so that I could try to figure out exactly what was going on with the Onan Marquis 5500 LP generator. Symptoms were previously described as the generator would start, but would immediately shut down without any load. I finally learned how to get the troubleshooting codes and ended up with a secondary code of 36. A quick perusing of the owners manual resulted in a diagnosis that I had suspected and hopefully will be confirmed next weekend. Apparently, when the generator is being used in cold temperatures, there can be problems providing the proper rate of vaporization for the generator. The primary cause is that the LP cylinders should be at least half-full. I suspected it was a propane problem, since our dealer stated up front that about all of the problems they have seen are propane feed related. I brought the tanks home, one empty, the other only partially full so that I can get them filled and hopefully remedy the situation. I did go prepared and took the Honda 2000 with me for the sole purpose of charging the rigs batteries (I do not remove them during the winter). Ran the small genny for about an hour and when I left the batteries were showing 2/3 charged. Hopefully with filled propane tanks I will complete the charging process Saturday with the on-board generator. An update will be posted.
Bingo

[Ozz]

Sounds like you have a good line on it.
I bet if a guy had a warming wrap, like on batteries in the winter, on a low tank that it would operate fine. The possible problem is that you may not have 120 volts for the wrap if you need a generator. Maybe a 12 volt wrap?
I know refrigerant and Propane are similar in that they have to have certain pressure to transfer the contents to where they are needed.
I brought in a tank of refrigerant from my 10 degree truck and weighed it into the refrigeration unit, but I had to heat the container with a little propane torch to get it out.

Well, like this:
http://www.powerblanket.com/Gas_Cyli...mers-c-29.html

[bncinwv]

Thanks Ozz, it sounded like a good idea until I saw the price for one blanket for a 40 pound tank. Woweeee!! Perhaps I should just wait for a warmer day to do the monthly generator loading recommended by the manufacturer!! C'mon Spring!!!
Bingo

[Jim Jarvis]

Bingo, I cannot run the same genny as yours at times and it's a combination of outside temp. and propane level. I've seen times where I would have to switch over to the full bottle of propane and it would run fine.

[Ozz]

The way it works is the liquid changes state to a gas when used, it 'boils off', this action causes the liquid to cool off even more, the less Propane you have, the colder it gets, dropping the pressures to the supply.
A full, or 1/2 full tank will operate much better, the generators use a large volume of propane, your furnace, stove and water heater use a relatively small volume, so the loss of pressure isn't noticed as bad.
This is where the expensive Propane blanket would come into play.

[Dixiedawg]

We had similar problems with our 2010 Mountaineer Onan generator. I talked with the engineers who manufacturer the regulator and was surprised to find out that the regulator is designed to use both tanks when running the generator. There is also check valves in the connection lines which can be a problem when installing refilled tanks. Follow the procedures outlined in the owners manual when installing refilled tanks. When I understood how the system worked, and made sure there was propane in both tanks, my problems disappeared. We boon docked at a NP in Yosemite last May at 10,000 ft and 21 degree nights. We ran the generator 6-7 hours a day between am & pm, and each day I refilled both tanks. You don't want to know what I was paying for propane!!!!

[bncinwv]

Dean,
Are you referencing the "Owner's manual" or the "Operator Manual". I cannot find anything about refilling tanks in the Operator Manual??
Bingo