Generator Voltage Variation and Frequency DOP Problem

Are they operated in Synchronisation or are they operated in stand-alone mode?

I would suggest to have a thorough check on the AVR & the Governor of the DG Sets.

What is "DOP"?

Go for TA test form gen vendor.

@ Electricalexpert65: Its standalone mode, No synch.

@ Tornado: Sorry Sir, Its typing mistake, DROP not DOP.

Thanks for your replies.

Rgds.

Not enough information:

1) On this unit, you should check and see if the Voltage variation is accompanied with a change in the frequency (rpm of engine).i.e., when you increase the load to 1200A, is there a frequency (rpm) increase with Voltage increase or drop in rpm with voltage decrease (or the opposite...). Also, is the voltage variation on the 3 phases or on one or 2 of them only.

2) On this unit, how does the load drop to 600A? is it that you shed some load (put off) to reduce it to 600A manually and then the rpm pics up? OR the engine by itself just drops its output to 600A with the same load connected still?

Finally, some observations: The Voltage in 1) cannot be going Up and down sporadically, without some different reasons, unless you have a loose connection or bad joint in the AVR which starts to misbehave at high load (high excitation current produced by the AVR). But this is speculation and needs more input as mentioned.

On the 2nd engine, it could be that the governor that controls the fuel rack is behaving: mechanical or electrical problem, depending on the installed system.

QAMAR:

I don't know for sure about the problem you are facing since generator is not my expertise but I am pretty sure that the gurus here will give you a hand troubleshooting the problem. Hope that you will give them more details about that.

Some of comments would not solve the problem immediately but after we go through all of them, we will have a clearer view on over the things which I think they are much valuable. Most of guests and new comers come on here just want to have an immediate correct answer for their problems. It will not work out that way.

Could you do me favour by updating the problem after you find it out? This would be used as an experience which I think it will help the others in the future. Consider the time it has taken for you to log on here and the other times of other people to read and look for the answer. Your updating would be highly appreciate.