As a periodic evaluation of condition, we'll be trending the Pump Station Pressures to watch for changes in the Pump Performance.

The attached plots show the pressure trends from the pump stations at the three buildings for the past 30 days.

There are no obvious steps indicating a pump stating cavitation--I don't really expect this out of the blue.  But if the system is taken down (Pump spun down) for any reason and then brought up, that is when cavitation has occurred and the pump pressures change.  This will be obvious for the corner station as the other pumps will compensate for the cavitating pump.  Hmmm, if this happens at an end station though...I expect the VFD output will have to increase to make up for this if if can.  I've only seen this at the corner so...   Anyway, I include the VFD output for the ends to look for this.

Observations:

Corner Station:  Bizarrely, the first pressure out of the Pumps all show almost perfectly flat tends--look at the scales; I can't explain this.  All the other pressures show a somewhat regular glitch up; this may be dailyish but seem a bit irregular.

EndY: Nothing new here.  Pressure and VFD output steady.  The long documented daily and weekly glitches still present and the daily temperature swings evident on the VOUT.

EndX: Same story except there is no regular glitches and the building must insulate things from the temperature fluctuation as there is no daily signal in the VOUT.