david.barker@LIGO.ORG - posted 12:37, Wednesday 25 February 2026 (89266)
h1sush12 SWWD tripped due to excessive PM1 movement, caused DACKILL on all HAM1,2 LIGO-DACs
The PM1 suspension started swinging longer than usual and exceeded its RMS trip levels for 20 minutes continuous at 11:44 PDT this morning. This caused an IOP DACKILL on all three LIGO-DACs.
I was able to reset and bypass PM1 and restore the SUS DAC drives at 11:57.
Currently HAM1 SWWD has PM1 permanently bypassed so this cannot happen again.