Honda standby generator start at -9° F

ChrisOlson

I made a video that shows how a Honda EM-series generator can be started at 9 below just as reliably as in the summer with nothing but a 75 watt heat lamp for preheat. The generator had not run for 24 hours before this startup.

https://www.youtube.com/watch?v=3fGxOdrv9nI

With our old LPG generator I'd be out there fighting with it for two hours to get it started at these temps. And then it would usually run for a few minutes, the carb would turn into a solid ice ball and it would quit. This Honda is so trouble free and reliable that it's almost a sin.

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Chris

papa

Re: Honda standby generator start at -9° F

ChrisOlson wrote: »

With our old LPG generator I'd be out there fighting with it for two hours to get it started at these temps. And then it would usually run for a few minutes, the carb would turn into a solid ice ball and it would quit.

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Chris

Odd?... the carb should rarely ice. I haven't seen icing on my LPG genset until the ambient temperature approaches -25f (approx 10 psi tank pressure), or when the humidity is high. And when it does begin icing, it's always at the first stage regulator (because that's where the major pressure differential occurs). Yes, there's a slight pressure drop as the fuel enters the carb's venturi, but it's never been enough to invoke icing. My setup has two separate regulators - a standard BBQ reg at the tank, and a second (Garret KN demand type) mounted 4" below the carb.

ChrisOlson

Re: Honda standby generator start at -9° F

That Generac would turn the whole carb to frost, go so rich it would start to stumble, then quit. And that's assuming it would start in the first place, which it usually wouldn't unless I had a 45,000 BTU space heater blowing on it. The one morning when it was 36 below and we had black plastic on the tank and charcoal going under it to get enough tank pressure to get the generator to run, and never did get it to start, I finally gave up on it and decided I'd had enough.
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Chris

papa

Re: Honda standby generator start at -9° F

I'm not doubting your carb iced, Chris. What I'm saying is, that it isn't the carb's fault or the choice of fuel.

Pulling vapor ONLY from the tank (which I assume your system was), causes the propane in the tank to boil, producing the refrigeration effect which is seen as a cooling effect or ice forming on the outside of the tank. Same thing happens when we run two camp stove burners off a tiny one pound bottle - the bottle temperature drops because the propane is boiling, which is required to convert the liquid propane to a vapor.

If your carb is icing, then that tells us that an unusually high pressure differential is occurring at the carb's venturi. So it can only be caused by one of two problems - a defective or icing-up regulator sending high pressure to the carb, or you have a vapor draw system connected to a liquid draw bottle valve - the latter is seen as immediate and severe icing on the reg, and can only be eliminated by adding heat.

Ralph Day

Re: Honda standby generator start at -9° F

That's pretty cool Chris:roll:

Ralph

ChrisOlson

Re: Honda standby generator start at -9° F

papa wrote: »

If your carb is icing, then that tells us that an unusually high pressure differential is occurring at the carb's venturi.

Yes, caused by the throttle plate itself. And for the same reasons that cars that used to have carbs would ice in cold and/or humid conditions, and had heated air intakes, usually heated by a shroud over the exhaust manifold. Our propane supplier came and added methanol to the tank to help with water in the LP, but that didn't help either.

I finally decided LPG is best for tropical climates. I got better things to do than heat a 500 gallon propane tank with charcoal to try to get it up to 10 lbs of pressure in the winter time.
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Chris