Is there a way I may add the voltage measured by the SM120 to the emonHP/emonCMS inputs please?
I have a Shelly EM installed with a CT measuring heat pump consumption and one measuring the grid import/export. The figures from the Shelly do not match those reported by several other devices, both Voltage and Watts. For the ASHP it’s reporting 300W when the SM120 is reporting 420W.
Which Shelly EM?
The SDM120 is MID approved so I’d be very surprised if it is wrong.
I wasn’t able to get the Pro Em, as it was out of stock.
I’ve raised a ticket with Shelly.
Are you looking at active power (the _P feed) or the _VA feed from the SDM120?
The former is the one to use.
I don’t suspect the SM120 or Emonhub/Emoncms to be at fault.
In Emoncms I am looking at the “electric_Power” input in Emoncms.
While the ASHP is idling at 15.8 W (from SM120) the Shelly EM is reporting -4.15 W 
Might it be related to the voltage and power factor?
480 W on the Shelly, while SDM120 is reporting 674 W.
The SDM120 also measures PF. It’ll be in input and possibly a feed if so configured.
Thank you. Just tapped through the displayed data on the SDM120 and the power factor as reporting 0.34. Shelly reporting -0.0.8
I appreciate these are momentary snapshots but for the stats I’m able to track in Home Assistant the graphs show a consistent difference.
The SDM120 is at the end of a 10 metre cable run, but connected to the same consumer unit as the Shelly. The Shelly is on the same isolator as the EM115 (for GivEnergy inverter) so am I correct in thinking that means they are all “on the same circuit” ?
