Sonoff pow R2

Has anyone bypassed the Triac in the R2 and used a a power minitor only.
I’d like to monitor the power consumed and the voltage applied to an immersion heater element.
Minor gotcha is, its a pWM supply and the peak mains voltage goes as high as 265V.
So what’s designed to consume 3KW at 240V , will take considerably more at peak mains volage
and will exceed safe working limits on the switch.
The reasom its PWM is as soon as the power generated by the solar PV exceed 1Kw, its used to heat the domestic hot water supply.
Also how much current re-enforcing of the tracks on the pcb ?
I have got one yet so a piccy would be useful
Thanks

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I managed to find some piccys of the inside of the ow R2 and its a relay used , which is tottally
unsutable for switching high current, the contacts will pit very quickly, causinging arcing , especially when disconecting the load, which even though it is supposed to be resistive
will have an inductive component , and will produce a back emf on disconnect.
Especially as there is no way of synchronising switching close to the zero crossing point.

The original question stands , has anyone bypassed the switch and just used for power monitoring ?

Hey Richard, sorry for reviving this old topic. I’m using the ImmerSun diverter to achieve that. The device costs around 500$ they claim reproducing a pure curve and they call it trusine technology and as we all know they are just applying PWM with some dedicated hardware. I also thought of using POW R2 as a cheap alternative to achieve the same result (not quite similarly). My idea is to monitor the excess power and run automatizations or scripts to turn on the POW R2 switch given certain conditions in order to avoid the undesirable high frequency of ONs/OFFs that might occur. For instance, the screen shot below shows a perfect example of some of my real data where the implementation of such an automatization would be really lucrative. Yes the POW R2 would import a little bit from the grid since my immersive element runs at 1200W. However, it remains a cost-effective solution if we compare it to the manufactured version I linked above.

For now this in just a thought, but will soon try to implement it and will share the results on this thread.

image

Just a thought: Non contact power measurement with a $10 device like a pzem004t v4 (rated up to 265V) should get the job done nicely. For the load switching just utilize an properly sized relay :tada:

Immersion heater elements are so cheap when not smart. Depending on the water tank sizes it’s easy to utilize various elements in the same tank. So for example use 4 times a 500W instead of one big 1500/2000W one pwm dimming isn’t necessary and the elements “just” get AC voltage :raised_hands:

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