Wireless energy monitoring

[Radian]

  To pick-up from where we started looking at energy monitoring in @Jenki's blog post,

 

 

1 minute ago, SteamyTea said:

Shall order a couple when I get home.

Sure I can safely modify them to be wired directly into the storage heaters and immersion heaters as they are a gnats under 3 kW each.

 

I bought four of these on Monday to add to my collection. They're actually a little different to the ones I previously bought although look identical. I only mention this because I've not opened them up but I did with the other ones and the relay was printed with 16A@240V and they seemed OK with a 3kW kettle load. Although the 13A plug and kettle lead did warm up as expected. I sawed the bottom plate of those to get inside and the PCB traces were very well tracked for current and separation. 

[SteamyTea]

Right.

Are these the same units

https://www.amazon.co.uk/dp/B09QQCVGSX/ref=sspa_dk_detail_2

[S2D2]

Annoyingly I've been using a Meross equivalent for this but after recently comparing with real time smart meter readings, I've discovered they're giving a reading of 200W for a dehumidifier which is actually drawing 160W. Pretty useless then. Are the above more accurate?

[Radian]

On 17/11/2022 at 05:04, SteamyTea said:

Right.

Are these the same units

https://www.amazon.co.uk/dp/B09QQCVGSX/ref=sspa_dk_detail_2

You should have tagged me because I missed this. Probably. It's a bit tricky because not all Tuya compatible devices work with Tuya Convert. I linked the other one because I bought some very recently and they converted just fine.

 

8 minutes ago, S2D2 said:

Annoyingly I've been using a Meross equivalent for this but after recently comparing with real time smart meter readings, I've discovered they're giving a reading of 200W for a dehumidifier which is actually drawing 160W. Pretty useless then. Are the above more accurate?

Yes, well, converting them to Tasmota lets you calibrate them quite accurately but if you're not converting them, it's not much help.

[S2D2]

6 minutes ago, Radian said:

Yes, well, converting them to Tasmota lets you calibrate them quite accurately but if you're not converting them, it's not much help.

Calibrate beyond a fixed scaling? I can use that for a certain device but I presume it will be different between devices?

[Radian]

12 hours ago, S2D2 said:

Calibrate beyond a fixed scaling? I can use that for a certain device but I presume it will be different between devices?

https://tasmota.github.io/docs/Power-Monitoring-Calibration/#setup

It seems to adjust offset only. But yes, it's done for each device. I'd say it's usually good to within 20W before calibration. But this is obviously worth correcting.