Earlier this week, the DCM that I use to monitor my heat pumps started reporting on/off repeatedly. Here is my DCM Power Meter for the past 2 nights. Tuesday night is what’s expected, Wednesday night is the on/off cycle. Heat pumps work fine both nights.
Hmm, if we were dealing with a smartplug instead of DCM, I would have posited data dropouts, which can happen for a variety of reasons. But three things make me think it is something else that I have never seen.
The DCM pattern on the right looks like a clipped and down-biased version of the pattern on the left.
The DCM drops to zero have falloff and return curved edges to them - not typical of data dropoffs
DCM seems more unlikely than smartplugs to have data dropoffs.
My guess is that something happened with either the DCM CTs, CT connections or CT configuration/calibration (that’s in software and can original back at the Sense mothership). I would contact support@sense.com.
ps: We’ve seen the configuration/calibration for working Sense solar installations get spontaneously corrupted recently. Guessing the same could happen for DCM.
Level 2 support found that the DCM detection was inverted. Instead of power meter going up, it went down reporting an off state. Don’t know what caused it but I am glad it’s working again.
@jackc1102
Thanks for the update. Sounds like DCM is prone to the same “accidental/sporadic” reconfiguration issue that some solar users have seen, where a correctly configured, working set of second port CTs, gets corrupted.
