Reports until 09:06, Wednesday 17 May 2017
H1 SEI (SEI)
cheryl.vorvick@LIGO.ORG - posted 09:06, Wednesday 17 May 2017 - last comment - 11:19, Wednesday 17 May 2017(36233)
HEPI Pump Trends - Monthly Plot

Attached is a trend plot of 45 days for the HEPI pumps.  I included the pressure channels from the vertex, where we are currently pumping down after venting to view/clean ITMX.  Changes in EY and EX Vout signals coincide with the vent, so possibly due to intentional changes.

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Comments related to this report
hugh.radkins@LIGO.ORG - 11:19, Wednesday 17 May 2017 (36237)

Not sure if there were any intentional changes at the end station related to the vent that I'd think would impact these channels.  The changes appeared related to post shutdown of the pumps to do the Accumulator charge check and I would be suspicious of the motor restart after the check.  However, the pump speed is very dependent on the fluid temperature so looking at the VEA temps reveal a direct correlation with the pump speed, see related FMC log.  I'll give facilities a couple more days to smooth things out before more action.