CORE ASSEM. 3N4469 - Caterpillar

Engine: G3306B (S/N: RJ21-UP; NR41-UP; WR21-UP; SG41-UP)Generator Set: XQG135 (S/N: AL41-UP)Introduction
Do not perform any of the following procedures without reading and understanding the information first.The Air/Fuel Ratio setup instructions that follow are intended to maintain emissions for fuel with a Lower Heating Value (LHV) of 800 to 1600 BTU/ft3. The engine control strategy is not designed to run on any fuels outside of this range. Maintenance of emissions is not guaranteed on engines that are run on fuels outside of this range. Caterpillar® also recommends adjusting the Air/Fuel Ratio when the gas pressure regulator is serviced or inspected.Set the Natural Gas/Field Gas Fuel Supply Pressure
Calculate the required fuel supply pressure based on the site conditions using the formula below.Fuel Supply Pressure (FSP, psig) = (46 - 29.92 - (altitude [feet] x .001)) x .4912 + 5Note: The altitude in feet is a required input from the customer.This calculation should result in a recommended gage pressure of 82.7 to 172.4 kPag (12 to 25 psig). Set the gas supply pressure of the engine to this value.Determining the Ignition Timing
The timing parameters allow the customer to program the ignition timing of the engine to meet the needs for specific applications and installations.Note: The actual ignition timing at a given operating condition may vary from the desired timing value. The timing follows a trend of a timing map that is based on engine speed, load, and user input timing in the Electronic Control Module (ECM).First Desired Timing
The "First Desired Timing" is determined with the methane number of the primary fuel that is being used. Obtain the timing information for the specific fuel and site conditions from the local Caterpillar dealer. The timing can also be obtained using the Caterpillar® Gas Engine Rating Pro (GERP) software program.Note: If the fuel composition at a given site changes greater than five methane points, the timing will need to be reset. Contact the local dealer or use GERP if such a change occurs.A free copy of GERP can be obtained by going to the following link and searching GERP in the search field. More information regarding the GERP program can also be obtained from the website.https://catoilandgas.cat.comGERP can provide the maximum rating capability for conditions at a given site. Use the following procedure to use GERP.
Select the "Engine Selection" tab on the left side of the screen.
Under the "Application" option, select "Electric Power".
Select the desired engine by selecting the appropriate options from under the "Engine Model" option, and select "G3306B".
Select "NEXT" using the radio button at the bottom.
Select the "Fuel Analysis" option and input the fuel composition obtained for the specific site.
Record the site "Set Point Timing" value found in the "Results" box on the "Project" screen.Perform the following setup procedures, depending on the configuration of the engine :
Engines equipped with a single fuel system using the natural gas pressure regulator - Part A
Engines equipped with a dual fuel regulator (natural gas and propane) arrangement - Part A and Part BSetting the Ignition Timing
Use the following