Pump monitoring

[ptonsparky]

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[synchro]

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.

 

[ptonsparky]

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.

 

[ptonsparky]

I changed the pressure setpoint. Freq & Hz are not longer close.

 

[Hv&Lv]

Are the currents still screwy?

 

[ptonsparky]

No, but second stage hasn't had to come on all afternoon. I'll see more in the morning.The 12 hz prior to a real start has me more concerned.

 

[ptonsparky]

Intermittent connection at pressure switch was cause of low hz fluctuation prior to Heat Pump call for water.
The current fluctuation has not occurred since my OP. I must have fixed it.:roll:

 

[ptonsparky]

1