jeffrey.bartlett@LIGO.ORG - posted 12:12, Thursday 22 February 2018 - last comment - 09:37, Friday 23 February 2018(40667)
Swap PSL Chillers
Swapped the running chiller (Gromit) with the backup chiller (Wallace). No problems encountered with the swap or during the initial run-up. Ran Wallace for about 20 minutes to due leak checks and top up the reservoirs. The chiller is off right now, and is set for remote start control. Will prep Gromit for warn stand-by backup. Close WP #7338
Maik, Matt
There is a problem with the Diode Chiller when trying to do remote operation. Once in remote operation setting, with the chiller powered ON, but not running, the chiller puts out a signal (we checked by looking with a breakout board on the interlock cable connection on pin 3 and pin 7 and it gives a voltage/resistance when the chiller is turned on at the power but not running...this shouldnt be the case...there should be no resistance/voltage if there is no flow) that indicates there is flow (even though there isnt). When we power off the chiller completely, the resistance/voltage signal disappears (as expect). Beckhoff sees this supposed flow also and so thinks the chiller is ON (even when its not), thus not enabling any control via Beckhoff.
We are currently looking into if this is a setting in the chiller itself that we can change.
Pics are of when the chiller is powered at the wall, but not running. This isnt what we believe should be happening. With the chiller not running, there should be no resistance/voltage.
Jeff swapped out the front panel controller for a spare this morning. The diode chiller now functions normally.