Beiträge von mwpicard

Zitat von N20net

Excellent. Thank you so much for trying this.

So, we have two solutions to get people out of trouble:

1. RC snubber across the coil.

2. MOV across the Shelly contact.

I'd say the snubber is the better solution, particularly for heavier loads that switch often.

My preference when using controllers with internal relays for inductive, or heavier, loads is to always (where practical) use an auxiliary relay, to protect the relay in the controller. It's much easier to swap a failed relay in a socket than to replace/repair the controller.

Thank you again.

Alles anzeigen

Thanks to all that investigated this issue which would be a show stopper for many.

I have read all the suggestions but feel that this is important enough to warrant a clear final solution. As is, I am not sure if only one snubber per Shelly Pro 4PM is required (between L and N) or if one has to be put in for EACH output that is switching an inductive/heavy load (I think NOT as when the output goes high, it simply becomes connected to L). Anyone?

Seems like this issue should be considered a bug and not a wiring ¨best practice¨.

Can we get a definitive solution from Shelly product management?

Zitat von N20net

Another update. Connecting the snubber across L and the Pro 4 PM output (directly - straight into the screw terminals on the Shelly) seems to have fixed it. I've now performed hundreds of switching operations, with no crashes. So, my theory is EMC from the arcing contacts in the Shelly internal relay was causing the crash.

I'll think more about it, and do a (hopefully) final update later.

I am experiencing the same issue with several different Shelly Pro 4PM modules so we can rule out it being a single defective unit. I assume you are referring to https://shop.shelly.cloud/rc-snubber-wif…?search=snubber when you mention the snubber? I look forward to your final update as I think you have nailed the problem and workaround. Great going! Let´s see what the official reply/solution is also.

Hi All,

I am unable to find the list of supported MQTT commands and what is sent out for the new 2Gen Shelly 4Pro plus. Also, I cannot find in the built in webserver, how to edit the MQTT name to set a custom name. The default one if very very long ....

Thanks for your help!

Martin Picard