I recently installed a Shelly 3em to measure my ground source heat pump, NIBE 1250 on three phases.
The strange thing is that I see returned energy according to Shelly, not only consumption.Screenshot_20210604-172609_Shelly.jpg. I have checked all wiring and directions and everything is fine. The values on each phase are from what I've seen, positive, e.g. buying energy.
See attached screenshot.