Caterpillar diesel generators synchronizing problem

[0ASHE0]

Dear Gents,
kindly be informed that we had three caterpillar diesel generators 750 KVA (model: 3412) which are synchronizing with each other and synchronize with the national grid for load sharing and load transfer throug woodward EGCP-2 contol panels but during the last past days we notice the following problem: -

Generator address No.2
•Without synchronizing order: The speed during test mode or running from the local panel is 1500 RPM without hunting or fluctuation.
•With synchronizing order: The speed during running mode is fluctuating between 1490 to 1510 RPM with hunting which led to the generator doesn’t synchronize with the other generators or with the national grid as a single unit.

Does anyone know how to solve this problem?

Thanks,

 

[rcw retired EE]

Could be autosynchronizer settings jumping speed too much, or governor tuning or engine fuel issues or ???

Look at the signals to the generator from the autosynchronizer. Does the Raise Speed signal stay on too long, followed by a Lower Speed signal? Does generator speed go too slow/too fast/too slow /too fast/ etc. because raise lower pulses are too long.

Does autosynchronizer work on the other generators? That would isolate the problem to the one generator.

Or maybe the Raise / Lower signals are OK but the generator governor or engine has issues responding.

 

[edison123]

Clogged fuel line? Time for filter change?

Muthu

http://www.edison.co.in

 

[waross]

I've seen speed issues with a sticky governor fuel control valve.

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[catserveng]

What kind of governor is controlling the CAT 3412? The EGCP2 is a load share controller and synchronizer, so there has to be a governor. Most common for that engine was a Woodward 2301A.

Does the control system have manual raise and lower speed adjustment controls, like a Raise/Lower switch or a potentiometer? If so have you tried to make a small adjustment with that to see if it causes unstable operation?

Without some more information from you about the system, here are some possible ideas,

I'd assume you have checked things like wiring connections and such between the EGCP2 and the governor, make sure all connections are tight and that signal wires are in good condition?

The EGCP2 synchronizer output dynamic setting may have changed, have you verifed the settings are the same as the working units? Make sure the software switch for speed bias is set to the proper range for the engine governor being used, a while back had a similar complaint on a unit and found the speed bias setting for the software switch had been changed from +/- 3VDC to 05-4.5VDC, which cause erratic operation during sync.

Could be a problem with the speed bias input on whatever governor you have installed, not a common problem but not impossible either. Knowing what governor you have would help in providing some better info.

Could be an engine mechanical problem as noted above, but usually an engine issue shows up more than just when trying to actively synchronize.

Hope that helps, MikeL.

 

[0ASHE0]

Dear Gents thanks for help and reply,
kindly find the updated actions and feedback
we had three caterpillar diesel generators 750 KVA (model: 3412) with electronic fuel pump (PEEC)which are synchronizing with each other and synchronize with the national grid for load sharing and load transfer through WOODWARD EGCP-2 8406-120 control panels but during the last past days we notice the following problem: -

Generator address No.2
•Without synchronizing order: The speed during test mode or running from the local panel is 1500 RPM without hunting or fluctuation.
•With synchronizing order: The speed during running mode is fluctuating between 1490 to 1510 RPM with hunting which led to the generator doesn’t synchronize with the other generators or with the national grid as a single unit.
Others: -
1- The faulty genset working random after a lot of trails and when it sync with the others generators it working without any problems until they stopped normally and if we need to but it in the service again it doesn’t sync again and it starting hunting
2- Generator address No.1 had the same problem one time or twice but still working, just we stopped and starting it again and it sync normally
3- the speed bais output already changing fast from 37% to 42% while the others generators changed between 38% to 39% and they sync normally which mean that the controller already sending a variable speed bais value

The actions which had been taken: -
1- Check and test the continuity of the MPU sensor to the ECM and speed bais signal wiring.
2- BY ET module we calibrating the RACK position Sensor which installed in the diesel fuel pump without faults
3- Swapping between two generators No 2 & 3, the woodward control panel and still the problem in the same Genset
still the hunting problem as it is!!
may be the problem in the main bus freq signal or input
Does anyone know how to solve this problem?

Thanks