You can't always be the best
Ditto, Thanks Steve! I was looking for info on an older genset and couldn't find a Genset forum. I can't be the only guy running into roadblocks looking for service info and wiring diagrams so lets hope this turns into a great information exchange. BTW anyone familiar with propane gensets? We have an 25kw unit with a 3.0 GM 4 cyl that is giving us grief. Anyone have any fuel system info for that engine? Thanks in advance.
It was a shame to see a lonely forum About your engine...what's it doing?
Brand new unit, trying to get it to run off the vapour from a 100 lb tank. Seems like its starving for fuel. Not even sure if its set up for propane or NG. What would change to convert it from one to the other?
How big is the regulator on your tank? If it's starved for fuel that's one thing that comes to mind running off a 100lb bottle
Different fuel pressures, depends on how the propane regulators are set up..... do you have a regulator at the tank, and a demand regulator near the carb?
Will a 100lb bottle gas off enough propane to supply the fuel demand of the engine? For me, that was the second thing that come to mind.
Depends on the air temperature, but it should run fine for a while. If you're pulling vapor the regulator will freeze up and the tank will form ice all around where the liquid is in the tank after a bit. The other possibility here is that many LP systems like on the forklifts I used to work on pulled liquid propane and used a coolant water heated regulator/convertor to turn liquid into vapor for the carb. If you're feeding a liquid system vapor it won't run much if at all. Have a look around and see if you don't have a round unit with coolant hoses running to it along with a high pressure gas hose and a low pressure hose to the carb?
Yes the bottle has a small regulator and there's a larger one (demand?) at the engine's mixer. Should we loose the small regulator? I don't see a heated regulator. We were told it would need 3 420 lb tanks to feed it at full load. We just want to run it with a very light load so thought it should run off a 100 lb bottle at room temp. Might try some gentle heat on the bottle next.
I searched the forum for "genset", and found a handful of threads that would've been posted here if it had existed at the time. Now it's not so lonely.
Wait, what? If it has a GM liquid cooled engine, it should have hoses connected to the cooling system to heat the regulator.
I'll double check but pretty sure it doesn't. Just looks like a carb with an electronically controlled butterfly with a 3" square regulator hanging off it. Definitely no coolant lines to that regulator.
Information off all the tags please, and pictures if possible. If your tank and regulator are not icing up, lack of vapor pressure is not the problem, but probably would be running under full load.
Most Generators and forklifts draw liquid from the tank, then convert to vapor at the engine. You need the correct tank, to draw liquid.
Pictures before we do any more speculating. Or at least some model numbers off the regulators and mixer (carburetor). There are only a handful of fuel systems out there for gaseous fuels and once we know what yours is it will be pretty easy. Propane generators are my specialty.
Pictures will be coming shortly. Thanks, BV. PS- would I be able to attach a short video here?
I'm not sure if you could post an actual video itself on here but you can definitely put the video on youtube and put a link to it on here.
Yeah, the flow check sounds like it's working properly. Sounds like the engine was originally set up for natural gas where you have constant flow because they suggested three LARGE propane tanks. I'm guessing (Guessing!) that it's set up for vapor not liquid, and you need bigger tank(s), or put a heated convertor/regulator on there and feed it liquid (turn the 100# tank upside down). That's why rather large forklifts can be run off a 25 pound tank until the propane is used up, they feed liquid and the engine heat converts it to vapor.
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Thanks for the quick reply lantraxco...... I would like to find a straight fitting to eliminate the flow control valve and see what happens. I also need a shut off solenoid. Where is a good place to get that?
Any forklift parts outfit will carry them, or some propane dealers do car conversions, etc. Of course online. This place has several choices: https://www.propanecarbs.com/impco/fl-219solenoidvalve.html Problem you may have is finding one that will flow enough gas to do the job, most of the solenoid valves are only 1/4" pipe or 3/8" at best. Might be a special order kinda thing.
It's 3/4 pipe going into the regulator. It must be set up for flowing enough vapour with a solenoid valve on it.
You may need a 3/4" valve........
I'm not real familiar with that type of vapor system. Is that an adjustable orifice in between the regulator and the carb?
I've seen those before and always assumed it was exactly that, to set maximum fuel flow? Never took one off or messed with it though. Okay, looks like a Maxitrol regulator, probably a 52 here's a couple links: http://www.partsfortechs.com/asapcart/impco-imp53-maxitrol-gas-regulator-1npt-imp53-p-1179.html http://www.partsfortechs.com/asapca...eplaces-generac-051109-imp52-es401-p-555.html
Well, that's why I gave my comment a preface that I know little about these vapor systems, but on many propane carbs you have a power mixture valve, an adjustable orifice for lack of better words, that's adjusted with engine at high RPM at full load. I was just wondering if that's what the fitting is in between regulator and carb in post #19.
Learn something new every day?
Yep, that's what I find on the typical liquid systems with a vapor convertor, you adjust the power valve at the carb at high RPM/full load. Just wondering if that's the problem profrooky is having. :beatsme
Hey All: I set both the power valve and the regulator to spec and still acted the same. Until I get the tank flow control to not stop flow when it increases I can't really know what those adjustments will do. Stay tuned.
Well, good to hear the update, and I'm certainly not the expert on that type of system, which makes me curious about that valve at the tank, almost sounds like some kind of velocity fuse that prevents rapid release of propane if a hose were to rupture, curious of what the actual function of that valve is.
Hey Willie: Ya basically that's it's purpose. If you've turned on a propane bbq tank too fast you'll know how they work. Until you shut the tank off and the pressure bleeds off to release the valve the flow is choked off. Seems like a pretty simple valve actually, we tried to drill it out today and seems like a check ball that seats if the flow is too high. I would like to get a hose end without this valve and see what happens.
Does your tank have the new style OPD valve? Here's a quote about those and their functions: 1. overflow float that stops the filling process before the cylinder is filled past the 80% Max. This float is also designed to stop flow in the event the cylinder is tipped. A tipped cylinder w/o the OPD would dispense liquid and is a very dangerous situation. 2. Is a over FLOW check, this is in reality a velocity fuse, and is incorporated in the valve(opd) to stop the gas flow from cylinder in the event of a major leak. an example of this would be a blown hose, or a hose burned off by a fire. This is the feature that gives us problems when we open the tank valve to fast, and is recommended by some to only open the valve 360 deg, or 1 full turn then adjust your ned for more heat by opening the tank valve more. I myself have elected to make it a practice of opening the tank valve very slowly the 1st turn, then open it fully from there. 3. Is the discharge check, This feature prevents gas from being dispensed from the cylinder without having a device hooked to it. This feature can cause low flow problems if the connection isn't fully seated(tightened properly), or it might have the wrong seal ring on it preventing full opening of the discharge check. My 100# tank for my shop heater still has the old POL (Prest-O-Lite) valve, no safeties there!
OK, there are some wrong assumptions going on here. 1. The protection ball in the POL adapter will only drop momentarily when opened extremely rapidly. If you open the tank valve wide, as you should, with no draw, then it will quickly drop closed and then drop back open again when pressure equalizes which takes a few seconds at most. Then it will stay open unless the draw is extremely excessive, we are talking a 100kw machine loaded down, or more. So the regulating with the hand wheel is actually telling you that you are getting too much fuel, not too little, I believe from my view of this over the internet. Post a video I suppose for better confirmation. You could also try turning in the load block adjustment you have there between the reg and carb but mark it first so you can put it back if this theory is bunk. 2. The vaporization rate of a propane cylinder is something that happens over a long period of time, not right away. I frequently test large machines off a 5 gallon BBQ bottle and they run fine until it begins to ice up which takes many minutes. Run a cold water hose on the tank and it will run until empty with no problem. Are you running high pressure propane right into the regulator that is attached to the carb? If so then you need to run 12" WC propane there, need another regulator at the tank to regulate to "house" pressure. Also, I can't see inside that Maxitrol regulator but usually the spring is removed and those are mounted with the nose pointed downward just before the carb to act as a demand regulator. Let me see some more pictures of the total fuel system including the tank, and drilling out the flow ball is the right thing to do if you haven't done it already.
I will send more pics Monday and am also leaning toward eliminating the flow ball. With nothing connected to the tank you can open the tank valve and lots of propane flows freely. Put the hose back on (with POL adapter) and slowly open the tank propane will flow. Open it more than 1/2 turn and it stops. I assume this is the flow ball restrictor doing its job. Thanks for the help. I know I didn't reply right but my comments are in bold......
Hi Lan: The tank is brand new so I assume its got the OPD valve. The problem appears to be in the fitting on the end of the hose where it threads into the tank. I need one of those old school valves. Thanks for the info.
What is the model number on the carb? And what is the model number of the whole genset? But for sure before any more testing you need to get a 11" regulator on the tank. Drilling out the ball won't hurt, but I don't think it is any issue here. But that demand regulator can't handle tank pressure. You might need a bigger hose between the tank regulator and the demand regulator, though. That looked like about a 1/4" hose and 1/2 to 3/4 would be more appropriate. Any old hose will do for testing purposes if you are safe about your connections of course....
I'll add a couple more pics. So that regulator shouldn't see any more than 11" WC?
11"? So it says right there........duh!
It looks like it also says natural gas. It might run on propane but not well. You will need to turn that load block way down if it goes down that far, or add a tighter one if this is true. The purpose of the demand regulator is to regulate 11" down to 0" or -1" or so and then the load block is the mixture adjustment. It takes a way smaller propane orifice than for natural. Ignition timing is also supposed to be less but we can cross that bridge once we get the mixture down better. I think the problem thus far was probably the demand regulator being forced open by 50-150 psi propane and when you closed the hand wheel you were getting the pressure range down somewhere it could work with. I have successfully gotten mis configured engines to run clean by varying shutoff valves in this way, vise grips on a hose, etc. They will not run under varying loads like this but it proves a theory of excessively rich mixture when things get weird.
I guess the next steps are to Tee in guages and go from there. I'll continue the experiment Monday and let you know the results. One last question for now......What should I use on the pipe fittings for thread sealer? Thanks for sharing your knowledge.
If you are just scabbing low pressure things together for testing and the threads are brass to brass or aluminum I use no sealer at all and not too tight. It keeps the mess down. Leakage is usually minimal but check before hitting the starter switch, you know why. For low pressure threads I just use teflon paste or even good old Rectorseal just apply it very carefully so none gets past the first thread. I rarely use Teflon tape because it tends to break off and plug things downstream since it is a solid material. For tank pressure fittings I use about 2 layers of teflon tape covered carefully with paste, never any past the first thread and never too thick so that almost all of it gets sucked into the threads and not piled up all over the place. And I turn these threads in as tight as I dare depending on the female part I am working with (don't want to break it) but tank pressure has a way of leaking if you give it the smallest opportunity. For this job I would not bother to gauge the 11" pressure because as you can see from the tag it is not too critical. Just put the right tank regulator on and go. You might have to readjust the Maxitrol regulator for a slightly negative pressure at the outlet if there is a port you can test it at. Normally those regulators have the spring removed and then they are installed upside down and gravity on the piston provides the necessary force. This might be a different kind of system here.
Possibly relevant. HeavyEquipmentForums
When you get whatever problem fixed that is causing it to run poorly, it is amazing how well and easy to adjust a propane engine is. Just turn the load screw until it seems "happy" and you are generally good to go at all loads.
Hi BV: I got the unit running pretty decent now with no load on it. Plumbed in a regulator and with a little fine adjustment on it and with the tank valve open it will smooth right out. I know this isn't a permanent solution but at least we know the unit is capable of running properly. We still need to plumb in a shut off solenoid as well. Is there still a need to invert the regulator at the engine? I put a couple videos on You tube............... https://www.youtube.com/watch?v=V2IUy4lK5uk https://www.youtube.com/watch?v=mx1Uau1HfH0
Ah videos, even better than pictures, isn't modern tech great. By installing the adjustable regulator you are able to compensate for the undersized fuel line, high pressure to the Maxitrol inlet, a misadjusted load block, or anything else wrong, and it probably will not regulate varying loads like that, but at least you got it to run, which, like you say, is the main thing. I would not go messing with the Maxitrol regulator or anything else until you get it fed with a proper 11" W.C. 3/4" fuel line. My suspicion is that the load block will need to be closed way down, as propane is roughly 2.5x the energy as natural gas. Can you confirm that the unit is setup for natural?
Yes, the interweb is a wonderful thing! Any suggestions on a regulator (make, model?) to get the tank pressure down. If the only thing that determines if its setup for propane or natural is the load block setting then its set for propane (load block dimension is 9.5mm vs 14mm I believe). Once I get some more parts on it (regulator and shut off solenoid) I should check timing next correct? In your opinion would the 100# tank supply enough flow with the unit loaded? Thanks
A standard house type twin reg will work for full capacity: http://www.ebay.com/itm/Fisher-Cont...713?pt=LH_DefaultDomain_0&hash=item4634868c61 One of these would work good enough for testing: http://www.tractorsupply.com/en/sto...ssure-lp-regulator-200000-btu-hr?cm_vc=-10005 http://www.amazon.com/Camco-59333-Horizontal-Propane-Regulator/dp/B0024E6TX2/ref=pd_sxp_f_pt or whatever you can find in the hardware store. 200,000 on the regulator vs the 300,000 on the nameplate does not bother me but you should probably not use a 75,000 barbecue regulator. The 100# cylinder will be good enough for a good long run especially if filled all the way. It will freeze up after many minutes or hours, but you can keep it warm by running a garden hose on it while running. The timing might need to be backed off. You would probably have to call PSI on that. See if you can see what it is at right now and we can decide if it is worth doing.
Great, that's saved me a lot of time, Thanks a ton! I'll be off to the local TSC to pick up a regulator. Do you think they would have a shut off solenoid as well or will I need to source that elsewhere. Here's a screen shot of the settings info I have, with timing settings.
Hi BV: Would this work for the shut off?
That is the valve I use from these guys: http://www.partsfortechs.com/asapcart/gv50046001-solenoid-valve-12v-34-npt-p-1376.html I have not seen these available anywhere locally. They seem like a specialty item. That is great info there. It seems like all you should need. If you have a way to verify that the setting the zero governor (Maxitrol) is not bypassing gas when the engine is not running, with only 11" on its inlet, that would be good but I would not sweat it if you can't (it looks difficult). Then I would consider the load block setting an inital setting and after the timing is set, fine tune the load block for minimum governor/throttle position under varying loads.
Hi BV: I got the regulator today from TSC (Mr Heater, 11" water pressure at outlet, 1/4" NPT in and 3/8" NPT out) and replaced the adjustable one I had on it. Plumbed it in with existing hose and the unit would barley run. Teed in a gauge just past the regulator and it read 13" water with engine running (barley) and tank wide open. Will get a bigger hose (3/8" or 1/2"?) tomorrow and see if that cures it. Shutoff valve also on the way. I'll keep you posted.
You put the new regulator on at the tank, right?
Yes, right at the tank, I'm hoping a larger diameter hose will be the answer now.
You say it is 13" at the inlet of the Maxitrol? If so then your regulator setup is just fine for now. You probably just need to tune up the load block then.
I was reading 13" at the outlet of the tank regulator. As mentioned the engine would barely run. You think the load block adjustment will cure it or should I put a larger diameter hose on first?
If you were still using that tiny hose then I am sure the flow was far too restricted. My book says 1" or 3/4" hose is the right size for that short run but 1/2" might be good enough.
Ok, I'll get a 3/4" hose and see what happens. The hose should only be 5' long.
Hi BV: Finally got the shutoff valve and larger hose installed today. It will just barely fire with the tank valve barely cracked open. Open it any more than 1/8 turn and the engine quits. Removed the shut off valve and same thing. I have a gauge teed in at the tank just past the tank regulator. Reads 13" before cranking engine then drops off to 4" during cranking. Didn't have time to go back to the smaller hose and adjustable regulator but will try that in the morning to make sure it still runs good that way. Any thoughts about why the pressure is falling off. The 100# tank is feeling a little light so I'll try a full 20# tomorrow. This thing is starting to p@$% me off!
Either the regulator you got or the POL adapter is not flowing enough gas, it is that simple... HOWEVER, 4" might still be enough pressure to run it since the next stage is reducing it to negative. I have seen them run with no tank connected, until the fuel in the pipe was sucked out, so.... If you can get your hands on a bigger regulator setup, it is worth a shot, but I think that if that is any trouble you should try turning in and out the load block screw first since it is easy to do. You could also try checking the pressure coming out of the Maxitrol regulator to be sure that it is slightly negative when the engine is running if you can get it to run Another thought-if you can get it to run the previous way, measure the pressure at the inlet to the Maxitrol and see what it is at when it runs but be careful not to blow up your gauge if it cannot handle high pressure....
SUCCESS!!! Installed the Mr Heater tank regulator, large hose and shutoff valve, topped up the 100# tank and it fired right up and runs great. Starts every time and sits steady at 60 Hz. Next step is to put some leads on it to get our load bank hooked up to it and make it work. Thanks a million for the advice, much appreciated.
What was the major malfunction? It is not quite clear to me. Only thing I would do at this point is set the timing as specified for LP and fine tune the mixture screw for minimum throttle/governor position with load applied. You can do it better with an exhaust gas analyzer if you have one. I'm glad it finally worked. These gaseous converted engines can be a bear to figure out what is wrong with the sketchy documentation. I have 3 or 4 stories that took as much of my time and effort as this did you, all for similar problems and all with totally and completely different causes.
It's not clear to me either what the problem was, I'm just happy it's working good so far. I have a procedure from PSI that talks about setting the timing and adjusting the MAS screw based on O2 readings when under load. It mentions phi and Lambda measurements and UEGO, are you familiar with these terms?
Yes I am familiar but I don't know that it is necessary unless you have to worry about pollution control. I assume you have enough feel for engines to be able to get it in its happy spot without being too rich or too lean. Adjusting while watching for minimum governor commanded throttle position always works, too.
Well we put a load on the unit and it worked perfect. We actually exceeded 100% briefly and it still hung in there. I'll try to put a couple more short videos on You Tube and post the links. Didn't get around to checking the O2 readings but will at some point to see. Thanks for the help!
https://www.youtube.com/watch?v=mx1Uau1HfH0
Did you yell "Hooray" when you got it fixed?