Sorry, but I saw the meter. For whatever reason I happened to be standing there (I think I had just arrived at the plant and was seeing what was going on with the unit-I was the start up engineer and it was still the OEM's unit) looking directly at the KW meter. The frequency meter was within my perifial vision-either directly to the right or left of the MW meter.
The load jumped 6 MW, which represented a 50% load change, from 12 to 18 faster than the eye can blink, as indicated by the instantaneous needle deflection in the positive direction, much to my surprise, amazement, and frankly, disbelief.
The turbine generator (two turbines on one generator) slowed perceptably (the groan), the gas valve noise changed as the fuel responded and immediately after the squirrel was cooked to a crisp and most probably vaporized, the turbine tried to overspeed. Again, very audiable-the unit was only about 10-20 ft behind me with no obstructions-the panel was on the open turbine deck.
Except for the 'groan', and the 'sigh' I would have suspected meter malfunction. But the unit clearly had a load hit it and it responded. First time I ever heard it, but I have heard it plenty of times since. I got to hear the 'sigh' again when I managed to trip the unit at full load some months later.
ByrdJ, this was one of GE's original Frame 5 STAG units and the valves to the ST were either open or closed, the ST was a complete slave to the steam produced by the HRSG (that was before the term HRSG was coined.) Actually, this ST had two admission points because the HRSG was a two drum affair with a HP and a LP section. Neither was regulated. Stop valves were open or closed. The municipality that owned it is connected to the grid today, but this was over 35 years ago and back then they were paranoid about connecting to the "big boys." They believed that somehow if they did that the utility would take them over. Go figure.
David Beach, I don't understand your statement. Since the squirrel would have been a purely resistive load, how did that change the power factor? Isn't a purely resistive load conducive to maintaining unity PF?
rmw