sheila.dwyer@LIGO.ORG - posted 16:30, Sunday 25 September 2016 - last comment - 10:25, Wednesday 28 September 2016(29964)
PSL tripped
The PSL tripped around 21:37 UTC, it took us about an hour to recover from this . We called Jason and Peter, Jason called back and walked me through restarting it remotely. I added about 200mL of water to the chiller, there was water on the floor in front of the chiller. Jason confirmed that this is normal, and that the turbulence and bubbles in the chiller tube are from a known slow leak.
PSL tripped due to the power meter flow. The 1st attachment shows the power meter flow dropping just before the crystal chiller interlock trips. The 2nd attachment shows the power meter flow dropping ~1 second before the FE flow drops. Interestingly, it takes ~6 seconds after the power meter flow drops and the crystal chiller interlock trips for the crystal chiller flow to drop (3rd attachment). Not sure if this is due to the rate that the Beckhoff PC polls the crystal chiller, or if it really takes 6 seconds from interlock trip to chiller shutdown (I suspect the former). The full timeline of the trip, assuming t0 = 21:37:51 UTC (time of trip):
Filed FRS #6319.