btfsc
November 13th, 2007, 05:52 PM
In planning for my generator install I keep getting conflicting information on my gas meter and if it could supply enough gas for the generator and the house equipment.
Did some research and though others could use the info to help them when planning to install a generator.
The first file gasmetersize.pdf shows the capacity of a number of meters.
My meter is a Lancaster Model 240/250 which is rated 250 cfh @ .5" WC drop.
So the gas company is going to tell me I need a bigger meter for my 5243 generator that requires 245 cfh at full load.This is because the gas company uses a .5" WC max drop for the flow rating of any device.
If you look at the above file you will see the meter can provide 375 cfh @ 1" WC drop and 540 cfh @ 2" WC drop.This should not be a problem for me as the generator can operate over a 5" to 7" WC pressure.My gas company sets the regulator for 7" WC so I should be able to maintain 6" WC at the generator under full load.
Gas line are another item that you get conflicting advice about.
After talking to a plumber friend he stated that the chart that Generac has in the manual is the most accurate if you use the correction factor for the gas you are using.
He said the problem is a lot of charts do not state what is flowing in the pipe when giving the flow rates,some will show air to make the pipe capacity look larger, as the material transported in the pipe will determine the flow rate.
My line will be a 20 ft run of 1" pipe that should flow about 299 cfh.
The second pdf is the generac pipe flow chart.It is for water cooled generators but the gas does not know what it is flowing to.
Did some research and though others could use the info to help them when planning to install a generator.
The first file gasmetersize.pdf shows the capacity of a number of meters.
My meter is a Lancaster Model 240/250 which is rated 250 cfh @ .5" WC drop.
So the gas company is going to tell me I need a bigger meter for my 5243 generator that requires 245 cfh at full load.This is because the gas company uses a .5" WC max drop for the flow rating of any device.
If you look at the above file you will see the meter can provide 375 cfh @ 1" WC drop and 540 cfh @ 2" WC drop.This should not be a problem for me as the generator can operate over a 5" to 7" WC pressure.My gas company sets the regulator for 7" WC so I should be able to maintain 6" WC at the generator under full load.
Gas line are another item that you get conflicting advice about.
After talking to a plumber friend he stated that the chart that Generac has in the manual is the most accurate if you use the correction factor for the gas you are using.
He said the problem is a lot of charts do not state what is flowing in the pipe when giving the flow rates,some will show air to make the pipe capacity look larger, as the material transported in the pipe will determine the flow rate.
My line will be a 20 ft run of 1" pipe that should flow about 299 cfh.
The second pdf is the generac pipe flow chart.It is for water cooled generators but the gas does not know what it is flowing to.