Problems with propane

[Fred Mc]

I removed the 6500W Onan generator from my bus to use for emergency power at my house. When installed in the bus it was connected to a permanent mounted 50 gal.tank via a hose that had screw on connections on each end.
However, at the house I planned to use a 30 lb bbq style tank. This has a large plastic connector at the tank and has a suitable screw on connector at the generator end. The problem is there isn't enough flow of propane to run the generator. If you turn on the tank very slightly there is a very small flow of propane and if you open the valve on the tank more you can hear a "stopper" stop the flow completely. I realize this is a safety feature but I don't think there is even enough flow to run a bbx.

Am I missing something, or got a faulty hose, or the wrong hose or-or-or.

Any help would be appreciated as we're are in the middle of an unusual deep freeze and are having multiple power outages-and will probably have more.

I plan to eventually plumb the Onan into the natural gas feed to the house and put a smaller, quieter generator in the bus.

Thanks for any insight you can offer.

Regards

Fred

[TomC]

BBQ tanks run on vapors. Generators usually run on liquid, then the generator vaporizes it-this is the way a generator can get enough fuel to run it. You should check with Onan to see if the generator needs liquid or vapor. If it is vapor, then you need a different tank that will allow you to flow more.
Running a 6,500 watt gasoline generator on propane usually derates it to 6,300 watts. Natural gas is even lower btu wise than propane. My guess is that you won't get much more than 6,000 watts out of that gasoline generator running it on natural gas.
Best to buy a dedicated generator built to run on natural gas.
Freightliner brought out a dedicated propane engine. Based on a GMC 500 big block, we built it up with higher compression, run it with liquid propane injection. It is truly a rocket truck engine for less than 33,000lbs. Good Luck, TomC

[scanzel]

Another thing to is that the conversion from liquid to vapor is very slow when the temperature drops. So if your propane tank was very cold from being outside then the conversion is very slow. This happens on my propane gas grill in the winter when I us it I don't get as large a flame. The best way to go is with the proper fuel with the proper generator.

[robertglines1]

Hose on backwards? pop might be back-flow preventer

[Lin]

Several possibilities and this is from memory so subject to some errors.  One is as Tom mentioned that generators are often run from a liquid rather than a vapor port off the tank.  The liquid propane is then vaporized at the generator before being injected into the cylinders.  If this is the case, there would be a vaporizer unit at the generator.  I think they could either use an electric element or the generators coolant to heat the propane to vaporize it.  The port at the tank may be marked as liquid.  If the port is at the bottom of the tank, it is likely liquid.  If at the top, it still may be liquid but using a pickup tube to reach the bottom of the tank.  Vapor comes from the top of the tank. 

Did the supply from the bus tank to the generator come through a regulator?

Your bbq tank is vapor.  If it has an OPD valve, it will shut down a high volume flow as if it has detected an open line.  The old style valve, which were banned at least in CA some 12 years ago would not do that.

[opus]

Open it as slow as you can.  I have one that does that to me and thats how I get around it.

[Utahclaimjumper]

  Your not "getting around" anything,,,thats the way its designed on purpose.>>>Dan.>>>Dan

[kyle4501]

You aren't likely to get enough flow of vapor thru the line you have - probably can't vaporize enough propane to run the generator without heating the tank anyway.

I'd suggest getting a forklift propane tank and use the liquid tap - that ought to solve the issue of not enough flow to the generator.