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Join Date: Nov 2017
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Engine RPM Goes UP & Down Till the Engine is Cold

11/04/2017 9:40 AM

I have one no of 40 KVA DG Set run by the Cummins Engine.

DG Set RPM goes up & Down or we can say DG haunt's till the engine Remain Cold.

Fuel Supply controlled by the 12 V Solenoid

Once the Temp Reaches at 70C, It Disappears

I checked the Fuel Line, Changes the Filters still it Persist

Can anyone help on the possible Causes for this and how to remove them

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#1

Re: Engine RPM Goes UP & Down Till the Engine is cold

11/04/2017 9:45 AM
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Re: Engine RPM Goes UP & Down Till the Engine is Cold

11/04/2017 12:06 PM

..."It sounds like you are getting what we call "wet-stacking" from running unloaded. Depending on the governor the gen can surge and 'hunt' until it clears out.

If you run under load for a while, until it clears out, and then stop and restart after the engine cools down and the engine governor is again hunting you very well may have an issue there in the governor or the governor control if it's electronic."...

..."If the engine is hunting then the reason is the governor is unstable. Usually, there will be a gain setting on the governor. The governor keeps the speed constant. It reacts to any change of the speed due to the load varying. If the gain is set too high, the reaction to a very small load variation will be too great and will make the speed to overshoot the set speed. This in turn will now reverse the action and undershoot. This can keep going on ... hunting!"...

http://cr4.globalspec.com/thread/63099/Power-Generator-Surging

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#3
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Re: Engine RPM Goes UP & Down Till the Engine is Cold

11/07/2017 12:18 PM

What you said. Hunting is really annoying (in a DG set).

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