nutsinee.kijbunchoo@LIGO.ORG - posted 13:11, Sunday 30 August 2015 - last comment - 16:41, Sunday 30 August 2015(21030)
A mysterious lockloss at 18:23:10 UTC
There were no indication of anything was going bad right before the lockloss. No glitches in the spectrum, no earthquake, nothing. The saturation alarm yelled ITMX and DRMI was unlocked. The SUS OMC SW watch dog tripped but seems to have uptripped itself. After that the Guardian wasn't able to turn ETMX ESD driver on and the reset switch kept flickling. Sheila is on her way to the site so I'm waiting for her.
I noticed the light in the control room flickered at the exact time of the lockloss. I suspect a power glitch may have caused this lockloss.
I set the Operating Mode to UNKNOWN.
We went to reset the ESD box at both end stations. The high voltage supply was 0. We reversed the input back to where it was and solved the problem. ETMY railed after the power reversed so we had to unplug and re-plug the DAC to fix it.
Soon after we got the interferometer back, wind started picking up speed.
Note, Sheila clarified that they called Richard who walked them through a set of commands on the front panel in order to get the power supplies back up while at both end stations. ('Always a good idea to call Richard after a power glitch anyways.)