GE7FA Tripped at 2000 RPM During Ramp Up


Thread Starter

Jasween Singh

GE 7FA LCI breaker 52SS was tripped during ramp up at 2000 rpm. While the startup of GE 7FA gas turbine, LCI breaker 52 SS opened at around 2000 RPM but machine continued to ramp up to FSNL. Is it possible or the machine should abort the start?
Well, if there was sufficient fuel AND the exhaust temperature didn't reach maximum then it's possible the unit could accelerate under its own power.

The real question is whether it was good for the turbine to do so--good for the hot gas path parts. The LCI usually provides some torque all through the start--but never more than is required to maintain the desired acceleration ramp rate. And, if the turbine is developing power and "assisting" the LCI then the static starter will back off it's current.

Have you looked at the trend of fuel flow and exhaust temperature versus speed? Have you compared it to a normal start-up when the LCI is providing torque?

Without actionable data (trends of the start in question and of a normal start) showing exhaust temperature and speed and fuel flow-rate and LCI parameters it's not possible to provide much more information than this. And, it would also be necessary to examine the application code running in the turbine control system to see if it should have aborted the start when the static starter breaker opened.

By the way, what caused 52SS to open? (In other words, what were the Process- and Diagnostic Alarms annunciated prior to 52SS opening and shortly after 52SS opened?)