Low tech load-shedding notification & control mechanism

Calling on the IoT wizards… Total noob here so I please need your distinguished opinions and input

I am looking for a relatively low tech and cost effective (read cheapish) solution to detect a power outage event (such as load-shedding) and then remotely switch off certain socket outlets and switch on maybe one or two smart bulbs to announce the fact that the grid power is down and then also the reverse when power is restored. This I would like to do specifically without having to implement Home Assistant or any other hubs for that matter. It should also be able to work in the local WiFi network and not only via the Internet.

Without knowing much, I was thinking along the lines of detecting the ATS signal from a Sunsynk inverter using a NodeMCU and then sending http control requests to Sonoff Mini R2 switches either in DIY mode or Tasmotized that controls the feed to the socket outlet of typical high power consumers. Would have preferred off the shelf smart sockets but these seem to be no longer easily flash-able with Tasmota OTA since most of them are Tuya based as far as I understand.

Not sure if the above method would work but any similar method of control would suffice. Does not need to be any brand specific.

I am sure this is relatively easily doable and I would really appreciate any direction in this regard.

It is possible to do Tuya local control now, and there is a python solution around that can talk to a Tuya device locally once you’ve extracted all the keys. Personally I still prefer Tasmota, the amount of time clicking through the Tuya IOT site alone (to get everything activated so I can obtain the keys) was bad enough that I will seriously try to avoid Tuya in future. But it really isn’t as bad as it used to be, it is no longer cloud-only. It might be an option for some people.

Correct me if I’m wrong but the standard approach is to split the DB into essential / non-essential loads?

I have a similar problem: my main DB can be split, but the “far” DB, where most of the big things ended up, only has a single feeder, so that cannot be split in the normal sense with two feeder lines, one essential and one not.

So I bought this, arrived on Friday:

It’s Tuya, which I like: really simple to get going, everything works together across brands, cheap, and you can “upgrade” to local control and Home Assistant if you want. There are eWelink / Sonoff versions as well.

It’s a motorized breaker, like you would get on an autocloser earth leakage. The current rating is very high when compared to relays. This one is quite configurable with selectable overcurrent, over/undervoltage, khw measurement, timers, etc.

So my kitchen DB will be split and the heavies are turned off when they should be over wifi. Not foolproof as a dedicated feeder, but it works. If your wifi & internet are on essentials, this will work fine. Better option would be local control, but you don’t need to start there. You can also go for a Shelly Pro, which has a physical ethernet connect with an external contactor, since the Shelly can only do 16A. (I actually bought a couple, so aircons go immediately when LS hits, stove if batt < 50%, etc.)

What’s also cool about this one is that you can configure the current limit, so the stove can go from “full current” normally to 1A during load-shedding. That way the gas-hob igniter still works, but it trips if you turn the stove on.

Tuya lamps to signal loadshedding are a dime a dozen. Detecting LS is also easy, just wire a Tuya in-wall switch on UPS power to a relay on grid power. When grid drops, relay switches and a scene takes over. You can do all of this from your phone and later upgrade to Home Assistant if you outgrow it.

I’m curious as to why you don’t want to use home assistant?

Not the OP, but I’ll give my reason: too complicated to get going. I’ve got it running in a VM, got localtuya (that @plonkster was complaining about) configured, but now, geez, I’m tired. So I’ll get there, but not today, and not tomorrow :slight_smile: For right now, knowing that particular door is still open is enough.

Thanks Plonkster. Based on your and Marius’ input it looks like I need to broaden my horizons to include the Tuya stuff…

That is indeed the preferred method but I sit with a similar problem that Marius have highlighted. Not practical or cost effective to get everything separated.

This solution will not be for myself but an elderly person not keen on any tech stuff. It just need to work as automated and seamless as possible. I will however be implementing Home Assistant for my own setup as soon as I have upgraded it to my intended final configuration but that will only be somewhat later.

Thanks for your input Marius, it seems quite interesting and might just work. I will look into it.