Generator Over Frequency Shut Down?

One way would be if there is a sudden drop of load, with slow response from the generator's governor.

Do you have any troubleshooting manuals for the genset that you can refer to? Is it possible to contact manufacturer for after sales technical support? I mean, that's the fastest and the safest way to go to solve your problem. First step.

If you have the feeling you be able to provide solutions faster than asking the tech support, you may wish to.

Tornado's comment is also worth to try.

Others might have inputs, similar solutions to problem like yours, just hold on a little while.

Check your frequency meter when it starts up and periodically until it shuts down. That will let you know if the governor is drifting or if it is a sudden load change as Tornado has suggested.

it is a gradual increase and then shut down.

and also its not a constant increase it, it goes up then down then up ........and so on until its shuts down.

Hunting due to insufficient damping in the feedback caused by ......can't tell from here.

Do you have manuals for the machine?

Old issue? Or; New issue?

Is the generator having the issue when stopped under load or unloaded condition?

Or both?

Old Issue:

Consult the IOM and the generator drawings.

Most likely you are getting the alarm(s) because of the generator shut down logic.

Many control systems remove power and signal inputs to all auxiliary equipment as soon as the stop signal is initiated. (This includes interrupting the feedback signal to the frequency monitoring and control circuits.)

This allows the operator to know the status of all alarm(s) functionality.

New Issue:

Possible governor component failure or governor needing calibration and tuning.

Possible frequency meter component failure or needing calibration.

What: type of prime mover, governor, control system, how old, initiated the actual trip, rate does the frequency rise, type of loading, was being done when the trip occurred, did the factory say, etc., etc.?

...." Loss of an interconnection, while exporting power (relative to system total generation) will cause system frequency to rise. Automatic generation control (AGC) is used to maintain scheduled frequency and interchange power flows. Control systems in power plants detect changes in the network-wide frequency and adjust mechanical power input to generators back to their target frequency. This counteracting usually takes a few tens of seconds due to the large rotating masses involved. Temporary frequency changes are an unavoidable consequence of changing demand. Exceptional or rapidly changing mains frequency is often a sign that an electricity distribution network is operating near its capacity limits, dramatic examples of which can sometimes be observed shortly before major outages. Frequency protective relays on the power system network sense the decline of frequency and automatically initiate load shedding or tripping of interconnection lines, to preserve the operation of at least part of the network. Small frequency deviations (i.e.- 0.5 Hz on a 50 Hz or 60 Hz network) will result in automatic load shedding or other control actions to restore system frequency. Smaller power systems, not extensively interconnected with many generators and loads, will not maintain frequency with the same degree of accuracy. "...

http://physics.stackexchange.com/questions/2641/how-does-load-affect-frequency-on-the-power-grid

Of all people, Murphy oughta know what could go wrong.

You do know Musany, that in order to be assisted, you have to answer some reasonable questions.

Are you there?

Dear Mr.musany,

One possible cause could be severe earth fault occurring in a definite interval, as a result, the load is cut-off and the Engine Speed shoots up and stop the engine. When the frequency goes up the governor should regulate the speed (which does not happen in your case. ) and engine should not stop.

Pl. check for earth fault and check.calibrate the governor.

A similar situation was faced by us some time back and earth fault was the source of the problem, but engine did not stop.

DHAYANANDHAN.S

??

I would like to ask if your machine is running in droop or isochronous mode. To me if it is a stand alone it should have no droop. Check your speed sensor maybe dirty or intermittent signal, check gap settings, resistance, voltage output. Just remember it all starts with com from the speed sensor to controller to gov that if all is set correct and in nick condition. I f i was given more info on the machine i would be more precise

Good luck