Hi,
I installed a Shelly EM and configured it in Home Assistant using the standard HA Shelly device integration.
This integration shows only 4 entities for the two clamp ports: Voltage, Power, Energy and, Energy returned.
I saw in the Shelly web interface that the EM also knows the power factor for each port.
What is the way to get the power factor and/or cos-phy and/or active and reactive power and/or current into Home Assistant?
I understand how some of these data can be calculated from other data. But i.m.o., the 4 existing entities are insufficient as the basis for these calculations.
Thanks in advance
I’ve an EM in the UK with a dual 120A clamp, but flashed the Shelly with Tasmota to make maintenance easier (lots of other Sonoff / ESP on Tasmota).
Good news: The Shelly EM does report power factor / phase angle / VA with Tasmota firmware and MQTT.
Bad news: The values produced aren’t credible, especially at low currents.
My suspicion is the Tasmota calibration curves for the sensor are way off, so suggest sticking with Shelly firmware unless you have the kit to recalibrate.
One clamp is on a 32A feed to an induction hob so a “complex load” is expected with HF noise from switch mode power converters, but an entire detached house giving a power factor of below 0.6 is not credible. At very low current, I’ve seen a PF of 0.06 - very low even for a capacitive dropper oven / hob clock PSU.
I should really get a reasonable clamp meter, attach a voltage probe, and measure phase angle directly. A resistive kettle plugged into the cooker breaker (common in the UK - 32A isolator + 13A socket) might also give a 1.0 3kW load as a test.
Thanks James,
important information indeed.
Reading the Shelly EM documentation online, I found that the Shellies support mqtt through their standard firmware. And one extra value published via mqtt is Reactive Power. So here I think I found a supported solution.
Continuing investigations
Can you create a screenshot?
I also use the internal integration and the power factor is there
Only with ColoT peer:
I see no Power Factor.
Correct me if I’m wrong, but since I’m using the Shelly integration, I am using CoIoT.
I solved this by using MQTT.
Shelly EM reports the active and reactive power via MQTT. That’s enough to calculate the apparent power and the power factor.
It also reports the Voltage. So I can than also calculate the current.
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