Installation manual

Natural Gas Generator Set Installation Manual-GF Series
Doc. 17855, Rel. 03/2014
5-4
5.7.4 Fuel Mixture Adjustments
IMPORTANT: Always use Nox and CO test equip-
ment to set emission levels.
1. Check for recommended fuel supply pressure
3.7-5.0 kpa (15-20 inches WC) at engine
mounted regulator
2. Check the operation of fuel shut-off solenoids.
5.7.4.1 Electronic Engines
For electronic engines:
• Model GTA855E see Cummins AEB 24.51.
• Model KTA19 SLB and QSK19, see Cummins AEB
28.07. Model 150 GFPA, GFMC, and GCDC are self
adjusting per engine manufacturer. Visit
www.psiengines.com for additional information and
updates.
5.7.4.2 Non-Electronic Engines
Some engines are site compliant capable. Generator
set certification is per local, regional and national
codes and may require frequent site testing. A
summary of the testing procedure is listed here. For
non-electric engines, apply 100% load.
1. Install the emission tester in the exhaust post
catalyst. The emission tester needs to read Nox
and CO in grams per break horsepower (g/bhp).
Install an O
2
meter per catalyst in port on turbo
exhaust elbow.
2. Connect the laptop to RS232 connection at the
Gill air-fuel ratio controller module. Start the
engine. Click on the Gill icon when connected,
click on View, then click on Fuel Valve Control.
(The engine has to be running for the laptop to
connect to the air-fuel ratio controller.)
3. On the screen, go to the Mode column, and click
on Open Loop. The air-fuel valve will go to the
closed position.
4. Apply full generator name plate load.
5. All adjustments and emission readings need to
be at full load of the generator rating.
6. Run at full load for 5 minutes. Check O
2
at the
turbo exhaust elbow. It should be at 0.5. If O
2
is
not at 0.5, proceed to step 7. If at 0.5, proceed to
step 10. THIS READING NEEDS TO BE WITH
AFR IN OPEN LOOP.
7. Adjust the carburetor air-fuel mixing screw. If O
2
is above 0.5, turn screw out. This will lower the
O
2
setting. If O
2
is below 0.5, adjust the carbure-
tor screw in, this will raise the O
2
.
8. Run the engine for 5 minutes and check the O
2
setting. Repeat adjustment until O
2
is at 0.5.
9. Under the Mode column, click on Close Loop,
and the fuel valve will open.
10. Run the engine for 5 minutes. Check the
exhaust emissions. Emission should be under 4
g/hp for CO and under 2 g/hp for Nox. O
2
reading, post catalyst should be 0.0 to -0.3.
11. O
2
reading at the turbo exhaust elbow should
drop to about 0.1.
12. If the emission readings are not correct, the air-
fuel ratio controller will need to be adjusted.
13. Under the Control column, record the number in
the set point box. (This is in case you need to go
back and start from the beginning).
14. Double click on the set point box. It will turn red.
Now you can change the set point value.
15. Change the set point value in small increments
(sample if the set point is -0.1550, change to -
0.1750), click Enter on the laptop. This will save
the new set point and the box will change back
to white.
16. Wait 5 to 10 minutes after every adjustment
before taking the emission readings. Be very
patient doing this part of the set up. Making a
change to the setting before emissions have sta-
bilized will make it very difficult to get AFR
adjusted correctly.
17. As the set point value goes up, the valve will
open more.
18. Under output, you will see % Open and Steps.
This is the amount the valve is open. The
maximum opening is 200 steps.
19. The CO and NOx reading will fluctuate.