EX had a dip in pressure around March 9th from 97.7 to 97.5, but other than that all looks good.
I forgot to link to FAMIS4530
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Looking over the past week, the daily EY gliches are at 20:44 PDT (03:44 UTC). On Saturdays a second glitch occurs at 21:04 PDT (04:04 UTC). Attached plots show 03:25 to 04:10 UTC for 3/19 and 3/12 (two successive saturday evenings in local time).
Here are data from End Y with most of the pressure channels and the controller output to the pump motor.
The attached plot gives support to this argument:
Something is happening with either the Pump motor or the VFD causing an increase in pressure out from the pump. This is evident by the increasing delay in pressure response as we proceed down the Pump Station Manifold. PRESS1 is the first after the Pump, the rest are after Laminar flow resistors and the filter. BSCSUP_PRESS is way down the line at the Chamber. The PRESS1 clearly leads the down stream pressures and it steps more sharply than the others. So this is a real pressure change increasingly softened by the accumulators and resistors etc as the wave moves down the line.
The VOUT signal is the PID loop responding to the differential pressure (diff between BSCSUP and BSCRET[not shown].) There is a big step down on this channel just before the pressure step up but that wouldn't cause an increase in pressure. So, I don't believe the motor is being directed to drive harder.
I'll look over the VFD manual to see if it has any scheduled items that might cause this? That just hardly makes sense...
Edit--Extra--If the output voltage of the PID controller could actually be manipulated without the VOUT data signal registering it, that too would be a possibility...Dave is looking closer at the computer.
