Reports until 08:45, Tuesday 22 May 2018
H1 SEI
hugh.radkins@LIGO.ORG - posted 08:45, Tuesday 22 May 2018 - last comment - 11:05, Tuesday 22 May 2018(42119)
EndY HEPI Pump Station Flashing "Pressure Not Okay"

The HEPI database running the Pump speed controllers monitors the differential and Pump Station output pressure; the usuals originally used to set the alarm level must have drifted.  The Pump Station filters were recently changed and this may have changed the steady state.
Will investigate.  FRS 10725.

Comments related to this report
hugh.radkins@LIGO.ORG - 11:05, Tuesday 22 May 2018 (42120)

The pressure okay alarm is set for the diff to be 70 +-2 and the last pressure on the Pump Station to be 80 +- 3psi.  The former is the set point and the latter is just from trends:
        field(INPA,"$(IFO):HPI-PUMP_$(LOC)_PS_PRESS4")
        field(INPB,"$(IFO):HPI-PUMP_$(LOC)_DIFF_PRESS")
        field(CALC,"B>68&&B<72&&A>77&&A<83?1:0")
The pressure sensors also have offsets in their zero readings that are hardcoded into the database but apparently these are no stationary.  I saw that the zero levels were not zero so I zero'd all the offsets and the pressures were close enough to zero to leave them that way.
After getting things back up and looking at the trends, I'd say the following:
The offsets were contributing to some of the change in 'normal' and the flushing and new filters contribute with plant changes.  All the pressures are lower now even out at the actuators.
The change in OFFSETs have pulled the average of Pressure4 up to about 78.5 where it had been right on the alarm edge at 77psi.  This should stop the Red flashing Pressure NOT Ok.

Closing Ticket.