thomas.shaffer@LIGO.ORG - posted 16:27, Tuesday 24 October 2023 - last comment - 09:04, Wednesday 25 October 2023(73704)
Swapped TCSX chiller for new chiller
Summary - Camilla and I removed the running TCSX chiller and replaced it with a new ThermoFlex 1400 SN#1153600201231003.
We've been having some issues with the TCSX laser relocking itself during Observing (ex: alog73331). This seems to be due to inconsistent water temperature from two of our three chilers, causing the temperature of the laser to shift slightly. We've swapped out SN#0110193301120813 for the new chiller and sent off the spare chiller for service. We input the settings from the CO2Y chiller and it the new chiller fired right up and seems to be outputing correct flow and pressure. We'll keep an eye on it the next few days.
Flow with the new chiller seems much more stable and the laser is operating at a slightly lower temperature (23.4C vs 24.5C) and a slightly higher output power (41.9W vs 40.9W). In the attached shot I'm unsure why the flow rate, as seen by the flow meter under the BSC, starts a bit higher and then over the course of ~4hours settles back to where it is now. I'd expect the system to settle much faster than that. For reference alog72267 is the last time we swapped the chillers and SN813 didn't show this.
When packing up our old spare chiller (SN#822) to be sent in for service, we found a small piece of metal, about the size of a bb in the outlet quick disconnect. This clearly wasn't helping the flow, but this chiller also had a refrigerant leak. Definitely time to be sent in.