Control.com - Nerds in Control

On page 24l speed Mark 4 (auto synchronizing), we want more description in this page about how to work this internal algorithm (BBL).

Thank you.

I've personally struggled with understanding how this algorithm describes what it does. It's interesting that GE didn't re-use the graphic with the Mark V. They have re-used the graphic from the Mark V in both the Mark VI and Mark VIe. essentially they all do the same thing (even the Mark IV): check for particular level of slip (not too high and not too low) and once speed matching is complete and the signals approach phase opposition initiates the breaker closing.

If a unit at your site is experiencing problems, please describe them and what you've done to troubleshoot it to date. Tell us about your turbine (Frame size) and tell us about any external synch check relay and whether or not it is known to be working. During auto synching of a Mark IV, there is usually an external synch check relay which must close basically at the same time as the Mark IV auto synch contact. Many GE-packaged units had an auxiliary, telephone-type relay that was driven by the synch-check relay that was the contact in series with the Mark IV contact. Quite frequently, either the synch check relay or the auxiliary to the synch check relay are found to be not working properly. As usual, the Speedtronic usually got the blame when it wasn't at fault.

If the unit at your site has a load gear (reduction gear), tell us what the input shaft speed is at generator synchronous speed (either 3000 (50 Hz) or 3600 RPM (60 Hz)). If the unit has a load gear, tell us what the value of TNH is when the unit is on line and grid frequency is at rated (as close to 50 Hz, or 60 Hz, as possible).