See fault 14966: https://web.accel.triumf.ca/ncr/dbfault.pl?faultgroup=CYCLOTRON&faultno=14966&btn_submit=Getfault
The flow rate sensor for T2 target cooling was exhibiting some instantaneous drops below the warning threshold, causing nuisance warnings. It was also dropping quite close to the trip limit. The reason for this unknown and this is unexpected since the sensor was recently replaced this winter shutdown.
Until the problem can be figured out and resolved, Ops has lowered both the warn and trip threshold values to 3.0 gpm and 2.8 gpm, respectively. This was done mid-day on June 7. This has been done in the past and is deemed safe to do as it is still within normal operating parameters (and a defeat is not required). The main reason for doing this is to reduce the chance of an accidental trip if the flow rate were to drop below the previous trip threshold of 3.0 gpm. These noisy blips do not seem to be dropping below 3.0 gpm, although they are close (see attached screenshot of June 6-8 data). The sensor history will be examined weekly, and if there are no drops below 3.0 gpm, these thresholds should be adjusted back to their regular values.
|