Help requested with 11 kV diesel generator set

Help requested with 11kV, 3MW generator. Our generator has just returned from a major overhaul, and we are in the process of recommissioning the set. The setup is that the generator supplies power onto a common busbar in parallel with the DNO supply. We supply site load and export any excess power onto the grid. We also have 3 CHP's onto the same busbar, but these have been switched off for the purpose of recommissioning.
The generator drives a 3MW Leroy Somer alternator. Load demand signal is by way of a 4-20mA signal from the PLC. Before the generator was sent away for overhaul, a 20mA load demand signal produced 3 MW output from the alternator. The engine governor is controlled by a Woodward 2301A speed control.
Yesterday we started the engine for the first time since it's return and it failed on overspeed during startup. After several attempts, we trimmed back the start fuel limit, which solved this problem.
Today we ran the set on load for some time. The alternator is now outputting 3.6MW, which is more than it is rated for. So for a 20mA demand signal, we are getting 3.6MW instead of the rated 3MW. The voltage is stable at 11kW, the frequency is stable at 50 Hz.
The governor has been overhauled, and the set has been set up and tested at the factory on their controls (not our controls).
Question is, why are we now getting too much power from the alternator, and how do we trim back?
 
What’s the speed of your prime mover? Ie RPM? whats your KVAR reading? What’s limiting load demand? What mode is the generator set in, Isoch or Droop? apologies for the many questions, just trying to paint a clearer picture?
 

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Created
jelliot,
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KennyKen,
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