aLIGO LHO Logbook

LHO FMCS (DetChar, PEM)

ryan.short@LIGO.ORG - posted 18:18, Wednesday 10 April 2024 - last comment - 12:06, Thursday 11 April 2024(77101)

Extra Loud Air Handler Noise in Control Room

Starting around 00:20 UTC (5:20pm PDT) this evening, the air has been much louder in the control room. Called Bubba to ask about it, and he says it's related to Eric's work today on the AHU-3 VAV (alog77092) and that the temporary ducting may have come undone. Other than it being louder in the control room, the duct should be fine and will be addressed in the morning.

I have not noticed a noticeable change in the IFO range since this noise increase, but I'll tag PEM and DetChar just in case.

Comments related to this report

eric.otterman@LIGO.ORG - 12:06, Thursday 11 April 2024 (77115)

Link

This particular issue seems to have been caused by tubing coming loose from the pressure transducer for the supply fan on the hot deck side of AHU-3. The control system no longer had a reference for the fan static pressure and opened the vanes to maximum which sent the duct static pressure to over 3" W.C. The air handler ran this way all night until I was able to reconnect the tubing and reset the air handler.