Pump monitoring

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synchro

Senior Member
Location
Chicago, IL
Occupation
EE
It seems like something must be screwy in the monitoring unit, sensors, and/or its connections if the frequency and psi are identical to 4 decimal figures.
 
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Location
NE (9.06 miles @5.9 Degrees from Winged Horses)
Occupation
EC - retired
They are usually pretty close but not always that close. HMI and VFD are connected via my local network. No cabling other than a 4-20 input to the VFD.

I see it is reporting some unstable hz around 12 in the 30 to 40 seconds before start up by a call from the heat pump.. Min frequency is set at 30 with ramp to that at .5 seconds, so something is amiss. A thought is I have relay contacts doing some bouncing in the zone control but that doesn't quite work out either.
 
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