SONOFF S31 power sensing plug + coffee maker = failure twice

Hardware
1

Not a complaint but an observation. I wanted to drop here in case it helps anyone else.

I have the now had 2 Sonoff S31 (with power sensing) that I used with a coffee maker [2 different models] at this point] STOP functioning as a power sensor. Looking at the most recent data power spikes to ~1300 watts under the 1800 watts Sonoff reports as Max Load.

Not sure the cause but not going to be trying this a 3rd time.

2

I would plug the S31 into a spike/surge (https://www.homedepot.com/p/Commercial-Electric-1-Outlet-Wall-Mounted-Surge-Protector-White-LA-9A-17/319526233) or (snubber - https://us.shelly.com/products/rc-snubber) protection outlet device, not just a wall outlet.

I have one on my sump pump, due to the high rate of cycling after rain storms and snow/ice melts.

3 Likes
3

Looking for the root cause:

Just curious what the power rating of your two coffee makers is? Make and models please? Do they use a thermal strip to make/break the heating cycle, where you hear an audible click as the steam comes on, or a nice smooth zero crossing cycle sophisticated electronic controller?
Did you pay $20 or $500 for each of them?

What integration are you using to sense power in HomAssistant from your S31?

Does your S31 have custom firmware? Which?

4

OK, I just noticed mine had stop reporting current, wattage, energy for some of my plugs. eWeLink stopped development of their eWeLink addon. eWeLink addon dropped some stuff and added a conflict detection of some sort that is auto enabled. I played around and ended up stopping the addon for now and that got my plugs back reporting the current, wattage and energy again.

Try disabling the conflict detection for awhile and see if that restores your values, if not then stop it. Hopefully your using something like SonoffLAN by AlexIT in the HACS repository.

5

coffee maker: Oxo Brew 8 cup. searching only gives me a AI results for 1400 watt draw. BUT if your thought was it was spiking power draw I didn’t see that in data before failure…data was showing a draw below the 1800 watt spec.

and stock firmware

6

Thanks…like the shelly option, thanks.