08-17-2010 08:53 PM
I am operating 4 n/g 3520c generators. over the past 4 years The gen sets have not been able to pull full load of 2 mw
I have resent performed aftercooler cleaning on the worst gen still not able to get 2 mw only 1750 kws.
performed borescope of turbochargers L and R show white on hot side of turbos the air side shows little shoot but no
oil build up again both L and R.
I have put ET on gen and riched the gas to engine was able to get 1825 kws but the NOX went out of speck.
Need some help on next thing to do
08-18-2010 05:58 PM
Lots of things that prevent ability to produce full power on these engines, you'll need to provide a lot more info to get any reasonable help.
First, island mode or grid parallel?
What fuel? Is fuel supply pressure adequate and stable?
What is site ambient conditions, altitude, temperature and humidity?
Have you connected ET to engine and do you know operating parameters? What is ECM indicated load at the maximum load you can achieve?
Was the site and units commissioning pre CAT guidelines? What are results of commissioning report? Did the engines ever make rated load? Are you sure rated load is 2MW?
What are the throttle and raptor valve positions at maximum load? Is the compressor bypass properly calibrated and what position is it in?
Try providing answers and as much info as you can.
08-19-2010 06:57 AM
Concur with Mike... Fuel in is power out. That's the first thing I'd go after.... Do these things run at the same time? If so will one unit running alone get the needed 2MW?
08-23-2010 09:36 PM
Fuel type is N/G UTILITY SUPPLY IS 15 PSI GENERATOR REGULATOR IS FISHER 133L 3/4 PSI TO 2 PSI RANGE
THE GENERATORS DO RUN PARALLEL WITH UTILITY 4160 VOLTAGE AT TIMES WE DO RUN ISLAND MODE IN EMERGY MODE.
OR RUN SEASON IS JUNE -SEPTEMBER AMBIENT TEMPS 85 TO 105 DEGREES HUMMITY RANGE 45 TO 95 %
ALTITUDE IS 500 FEET ABOVE SEA LEAVEL
MY LOCAL CAT DELEAR HAS HAD SERVICE TECH RUN E/T AND GATHER LOTS OF DATA OF ALL MENTION BELOW
LOCAL DELEAR DID PERFORM COMMISSIONING IN 2004 THE GENERATORS STARTED PERDUCDTION 2005 SUMMER
HAVE NO FACTORY DATA RUN TEST
GENERATOR RATING IS 2050 KWS
THROTLE VALVE SHOWS 100 % OPEN AT 1,750 KWS
TODAY CAT DELEAR SERVICE TECH PERFORMED MORE DATA RUNING THE AMBIENT TEMP WAS 75 DEGREES
WITH OVERCAT DAY THE GEN IN QUESTION PERFORMED UP TO 2,000 KWS AND MAINTAINED FOR FULL 2 HR RUN TEST.
I AM RUNNING OUT OF SUMMER TIME AMBIENT TEMPS THE GEN WILL NOT PULL FULL LOAD AT AMBIENT TEMP OF 85 AND ABOVE.
EXPECTING HOTER WEATER LATER IN WEEK 8-26-27-28-2010
AFTER SEASON JUNE-SEPTEMBER THE PEAK SHAVING PLANT IS IN HOT STAND-BY OCTOBER-MAY
ANY HELP TO FIND OUT WHY THESE GENERATORS LOSE LOAD.
08-23-2010 11:40 PM
So you are at 100% throttle, what is fuel valve position?
2 PSI fuel supply pressure in my experience is a bit low, had best luck at 4.5 PSI. Is this pressure remaining constant thru load range or does it drop off?
What is you air manifold temperature? This is one of the most important data points you need if you feel ambient conditions are affecting ability to run at full load.
Has anyone checked the calibration of the compressor bypass? For a while it was recommended to crack it open a bit at minimum actuator postion, some techs got a bit sloppy and opened it too much. Try going back to the bypass fully closed at minimum actuator position.
How about your spark energy and exhaust port temp numbers, is all that data indicating the engine is running a couple cylinders shy?
If you're going to live and work with charge density controlled engines you really need to learn how to collect and read the performance data, with 2 hours of runtime information you should have something that points you to root cause of problem. Was data stable or was there a drift in actuator positions or temperatures? Why only 2 hours? Was emissions data also taken, or was the E gain cranked until power came up?
What did your dealer tech say about the testing, any comments?
08-24-2010 10:58 PM
Has a factory evaluation of your been done to determine thefuel MN, wobbe index, LHV, etc?
Have you evaluated site specific deration curves been completed by the factory? If you have only the generic data then you need to ask for these.
Have the constituents of your gas changed recently? Has a utility process come on line or gone off line recently
Are you using Island mode sets?
10-02-2011 07:06 AM
I have a very similar problem, except mine is more prevalent in the hot environment, temps above 90 deg F in the generator space. We have had the problem in the space down to 42 deg F. We run in parallel with the utility. 2 gensets g3520 running at 1860 kw and at 15 kv. We have had changed throttle body, turbos, calibrated the bypass valve, calibrated the throttle. We have done everything that the local rep has suggested as in repiping the vapor extraction, air filters, etc.... This problem comes an goes sometimes daily, at times it will run for 60 days straight without a problem. fuel pressure is about 2.8 psi with other genset running and it is about 3.5 psi running solo. It happens mostly when the other engine is running, but it has happened often running solo. Rep just keeps telling me when it happens to call them and they will log the engine with ET and send it to the factory, meanwhile, they keep sending me the bills. This has been going on I assume since since the installation, but I can confirm that for sure since 5,000 hours. Ant help would be appreciated. Howard