Sonoff ZBMINI Relay - Initial Experience

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I just installed a Sonoff ZBMINI (X002PAP49B) in a location where I would have had to use a "non neutral" device if I wanted to add Hub control. Or a similar device like Qubino etc

My take on the device:

  1. It is a relay, only ON/OFF. You can hear the click if you are right near the device.

  2. Its simple, No advanced options that I could identify.

  3. Pairing the 1st time was trivial. I set the Hubitat to Zigbee include, plugged in the ZBMINI and it paired nearly immediately. It defaulted to the Generic Zigbee Switch driver which works fine.

  4. Wiring is super easy. You will need a small screwdriver to fit their terminal screws. The wires need to be trimmed to about 1/4 inch of exposed copper.
    Stranded wire takes a little care, I found wiring the fixture (which in my case was stranded) on the bench before getting on a ladder is easiest. One had to be careful there are no strands sticking out of the terminal strip.

Now the best part.
This device is called a two way switch, however here in the USA and likely elsewhere we know them as 3 way and 4 way.

The switches are not connected to mains power or the load. They are stated to carry a lower power signal that is "safer" than mains power. I did not measure any voltages so I can't attest to their safety.

It is easy to create a 3-Way (as shown below) or 4 to N way with this device. My switch runs are only about 20 feet each so I don't know if very long switch runs will be an issue or not.

Their diagram shows two "SPST" switches which are EXACTLY the same as a standard 3-way switch. In this case the "L" terminal would go to the black on the typical 3-way switch. Of course you can use it as a simple 1-way as well.

My conclusion:
I am not a Sonoff fanboy as this is my first Sonoff device. I liked the simple wiring. The device works well (so far). It's a relatively low cost device. It does not have any bells and whistles none of which I have used in the past ( i.e. Auto timer on / off etc).

And I get the "smart" function without having to go to a Non-Neutral switch, which I very much dislike.

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UPDATE: I've not experienced a log entry other that no or off posted at the time of the action. Continuous status updating was posted elsewhere.

UPDATE#2: I have noticed a slight ( ~ 1/2 second) delay of ON and OFF. We don't mind it but I though it was worth noting.

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2

Bumping this up rather than starting a new thread. I have around 10 zbminis around the house and they work great. I ran into an issue today tho.

I put a ZBmini inline my Boiler/Furnace/Hot water. I have a Boiler with an Indirect tank. Boiler heats up. Then sends this hot water to a tank which then heats up and this is how I draw hot my hot water. During the summer my boiler only runs when the tank calls for heat. We only shower/ need hot water at night.

I was going to make a rule to switch on boiler @6pm and off @2am and restrict the rule to be ON during weekends. All is well.

Then I cut the power while the ZBmini was ON. It shut off. Restored power and the ZBmini remained OFF. It's default is OFF if there's a power outage. You can see how this would be a problem especially in the winter.

Anyone have a trick around this?

Tldr: ZBmini defaults to Off when power is restored after an outage even if previous state was ON. This is no bueno.

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Found a solution to my particular situation. Probably won't help others but I'll post up anyway.

My Indirect tank communicates with my boiler via an ON/OFF dry relay aka an Aquastat. I'm going to source independent line voltage for the ZBmini and use the switch side to interrupt the Aquastat line on its way to the boiler. This way if an outage or ZBmini failure were to happen I would just be without hot water. The Boiler would still have power allowing it to produce heat. No heat in New England in the winter is not cool.

This will only help me for now tho as my tank will have a sensor instead of a relay in a few months when I upgrade.