Reports until 14:50, Tuesday 28 April 2026
H1 SEI
jim.warner@LIGO.ORG - posted 14:50, Tuesday 28 April 2026 (90038)
1 of 4 HEPI Corner station pumps have been off since Dec 14 2025 power outage, remaining 3 pumpstations were running at ~95% to cover since

Last week I tripped the HEPI pump controller valving out the BSC2 actuators, it took me until today to try to recover it. In the process of investigating this I found that one of the 4 corner station HEPI pump carts has been more or less off since a power outage in December. The remaining pump stations have been running at about 95% drive to cover for the lost cart. I am working on some revisions to the famis and asking to Tony to add a verbal notification if there is a mismatch in the manifold pressures for the 4 corner pump stations.

Nice to know that we have overhead to lose one pump station and still supply the corner HEPI with pressure. Drive is much lower now that all 4 are running again.

Attached image shows how long we have been running with only 3 pumps. Crosshair in the upper left plot shows approximate time of the power outage. Bottom right shows we have been running at ~1900 cts drive out of 2048 total available since then. We are back around 1100 cts drive now.

Images attached to this report