I have a 85 KW Onan generator that is made to run on natural gas. It has a Impco model 200 right above the carb and beofre that it has a Impco IT30 which I believe is a regulator. I have a gas well and it seems it does not have enough gas flow to run I have under 1 PSI to it. I also tried connecting propane to it and it would not run. What natural gas pressures do I need to get this running? Can you flood an engine on propane or natural gas?
I'm not finding a reference for Impco IT30 on the internet. Got a picture?
Pics
I see the regulator, very old and no reference on Google so I am not sure what it is. Probably 7" water column on the inlet down to 0" on the outlet or possibly 3.5" on the outlet delivered to the mixer. Natural gas is usually delivered between 4" and 14" water column, 28" water = 1 psi. Usually for proving purposes a natural gas configured unit will run (poorly) on propane. Do you have means to accurately measure gas pressure on this?
what is the onan model I have some old manuals might tell
I have only a pressure gauge to see and it shows under 1 psi. I thought maybe I could increase pressure at well head to 4 psi and that first regulator should knock it down? I will get model of Onan later. Thanks for the help
Buy or make a manometer out of clear tube with some colored water in it. 24" long on a piece of wood or something. The distance from the depressed water surface to the risen water surface is the gas pressure in inches. Can be positive or negative. Without this info we are shooting in the dark.
Upping the PSI won't do you any good, as Birken said you need to measure the WC. Easy hardware store manometer is clear tubing taped in a 'U' to a cheap wooden yardstick with some liquid in the bottom.
Not a expert on gas wells by any means but I wonder what the quality of the well gas is? Is it known to be of quality to run the engine? Maybe this is my learned tidbit of the day.
LP and Nat Gas operate at WIDELY different pressures and rates of delivery. To get it right will have to swap to LP Regulator and downstream Evaporator. LP is supplied at a much higher pressure usually still liquid where the conversion to a gas is a refrigerating mechanism thus the evaporator to heat that gas back up to keep it from freezing up. Natural gas is delivered in a gaseous form at extremely Low Pressure as noted where does not require the evaporator and regulator does not work off a liquid state. Check with your local LP supplier as they will have access for engine conversion parts.
I don't necessarily agree with all that. Propane can be delivered at a similar pressure to natural and usually gets regulated at the mixer to -0.5" where natural was traditionally +3.5" but if you have a good running generator engine and hook it to the opposite type of fuel gas it will usually start right up and blubber until you realize what you did wrong. But in post #1 he stated it was configured to run on natural anyway. A short run on propane would just confirm it is a working unit, in my view.
Had LP and Nat Gas generators at the Utility as BU power to switch yard controls. Had both IMPCO systems parts on hand, totally different internally. Had more than one service call to swap the controls when sent Wrong set up Generator system for a Replacement or New Install. Pretty certain NG ran at 4-6"water column no evap unit, LP was 9-13" h2o after converted in the evaporator.
IIRC could run a LP on NG but the system would not work NG trying to run on LP.
In the large scale units they are more customized toward the fuel type. But in the smaller ones under say 200 kw they are generally convertible, the smaller you get the simpler the conversion. Did a 100 kw unit recently that had a simple regulator and carburetor and no physical adjustment was necessary. But usually there will be some slight tweaks and twists to the regulator and/or fuel throttling valve, and sometimes ignition timing. Seldom change any hard parts.
I'll get a measurement once I get a manometer.