Does Sonoff ZBMini has dry contact?

Hardware
1

Hello out there,

I am looking for a Zigbee switch with dry contacts.
I have outside lights which are controlled by two dumb relays. The relays are switching 230V AC, but controlled via 12V DC. So I need a smart relay which has dry contacts to get this thing smart.

So far I found this Zigbee 3.0 Schalt-Aktor Mini 1 x 230V, 200W / 400W, für 230V Leuchtmittel | schwarz which should be the right thing for my project. Technically it looks like a sunricher relay ZigBee AC In Wall Switch SR-ZG9101SAC-HP-Switch

But now I found the Sonoff ZBMini which costs only a quarter of the iluminize. https://sonoff.tech/product/diy-smart-switch/zbmini/
It seems that the switch is separated from the 230V AC. I found different statements regarding this.
Sometimes they say this is a dry contact and sometimes they talk about 3.3V DC on the switch. The manual only says "dont connect Live or Neutral to S1 or S2.
So if there are 3.3V DC on the switch connectors, I could propably damage the Sonoff when connecting to 12V DC.

Somebody here who could help me?

Shelly is not suitable for me, because the motion sensor will also be zigbee and will be connected directly that it is working without the gateway.

Another smart relay, which does the job and is less expensive as the iluminize is also welcome. :slight_smile:

2

I don’t think the Sonoff ZBMini is right for your project without modification.

I get 3.3V DC between S1 and S2 when the L In and N In are powered via mains. I haven’t tried it, but you might be able to get it to work using a mosfet or optoisolator to act as a switch between S1 and S2.

3

So the ZBMini is powering the S1/2 with 3V DC?

Then it is not a dry contact…

1 Like
4

I managed to get my hands on both of them.

As you said, the Sonoff is powering S1/2 with 3.3V DC. It its perfect for using it with a separated switch. But every change of the switch is triggering the Sonoff. So a momentary switch does not work, but this is already mentioned in the description.

The Iluminize has 0V on the switch connectors. A switch needs a separate power source to be working.

Accordingly the Iluminize is a relay with dry contacts, the Sonoff not.