Common problem to 7kw model #5240?

[Duane Pulliam]

Kelly:
Is the problem I have with the 7kw mod. #5240 sputtering on startup for a few seconds before running up to full speed common with all 5240s? Everyone I know around here with the same unit has the same problem, only most are worse than mine. Does this eventually clear up with a some run time on the genset? Is it because the 5240 does not have a choke?

[Kelly Myers]

Hi Duane,

Remember this thread?

http://zillerelectric.com/forums/showthread.php?t=77

I'm guessing the plug didn't help the starting?

[Duane Pulliam]

Hi Kelly:
I was just waiting for your reply to my gas supply question and thought I would re-ask about if this is common or not. Yes the plug did help the starting but I still have to get a Hz meter and reset the gas regulator and gov. settings so it runs smoothly. I am still curious, since you are a dealer, do you see this as a frequent problem with the 7kw units?

[Kelly Myers]

Originally Posted by Duane Pulliam

Hi Kelly:
I was just waiting for your reply to my gas supply question and thought I would re-ask about if this is common or not. Yes the plug did help the starting but I still have to get a Hz meter and reset the gas regulator and gov. settings so it runs smoothly. I am still curious, since you are a dealer, do you see this as a frequent problem with the 7kw units?

We sell (3-5) 7kws a day. They are very popular where AC units are not needed. I get phone calls about them being broken 3 or 4 times a week. After I explain to them the fuel requirements, and how to set the fuel regulator and governor (page 12-13 of your manual), they all end up working. The 7kw do require being tuned in.

What is the total footage from the gas meter to your generator?

[Duane Pulliam]

Thanks for your response. My gas line from the meter is 1" and runs approx. 25' to the furnace. At about 18'-20' in from the meter, I teed into the 1" with 3/4". The 3/4" runs about 19' to the generator. That is - approx. 20' of 1" then 19' of 3/4".

[Kelly Myers]

So we have a total of 40', and I will figure you have four 90 degree fittings that count for 3' per fitting.

So we have aprox 52'

You can flow a total of 91,000BTU's from the meter to your generator with that pipe.

At the T you installed, you have 194,000 BTU's availble for both the furnace and the generator. If your generator is running, you may only have 50k-60k BTU's availble at the generator.

This generator will never run properly with this fuel setup.

If you do a seperate run from the gas meter to the generator, and use 1" pipe the whole way, you will be able to flow 144,000 BTU's, and the generator will then have enough fuel to run.

[irq3]

Here is an interesting blog about a generator improperly installed (fuel supply) and then corrected:

http://www.indovina.us/~mai/generator/

[Duane Pulliam]

Yes that is an interesting blog. However, in my situation, my existing gas meter is rated for 390,000 BTU/hr. My total load, including the 7 kw generator, is 255,000 BTU/hr. The gas company says they maintain a 7" WC. My generator requires a 5-7" WC. The main gas line into the house is 1". The gas supply tables that can be found on the internet show that I have more than an adequate supply to the generator for the size and length of my gas line to the generator, furnace and water heater. After the initial 2-4 seconds of sputtering upon startup, my generator runs up to full speed and runs fine. It seems that I just need to make some adjustments to the regulator/govenor/3/4" air port to get things fine tuned. Just haven't had a chance to play with it yet. If I put the 3/4" plastic plug in the air cleaner box, the generator will fire right up but then surges because the mixture is too rich. I have to play with that arrangement. All of the other folks in the area that I know of who also have the #5240, 7 kw models have the same or more severe problem at startup. It seems that Generac could do a better job of setting these things up at the factory. After all, they are pre- packaged for the home owner to self install.

[Duane Pulliam]

Also, after my generator has run and shut off, it will start and almost instantly run up to full speed without any hesitation, even if it's been a day since the generator has run. But if it sits all week between exercising periods without running, it will sputter for 2-4 seconds before running up to full speed. A friend of mine has installed two of the same models for his inlaws and they both have the same, only more severe problem. And they are both located only about 3' from the gas meter and are connected with 3/4" pipe, so gas supply is definitely not the problem there either.

[Kelly Myers]

Originally Posted by Duane Pulliam

Also, after my generator has run and shut off, it will start and almost instantly run up to full speed without any hesitation, even if it's been a day since the generator has run. But if it sits all week between exercising periods without running, it will sputter for 2-4 seconds before running up to full speed. A friend of mine has installed two of the same models for his inlaws and they both have the same, only more severe problem. And they are both located only about 3' from the gas meter and are connected with 3/4" pipe, so gas supply is definitely not the problem there either.

If it starts up on the first series of crank cycles, I wouldn't worry about it. I believe its programmed for 7 start attempts before it fails into over crank.

If its starting on the first crank cycle of aprox 10 seconds, there is nothing to worry about. Its just moving fuel through the regulator to the engine.