Unable to Trigger Contactors

  • Hello Everyone,

    I have just updated to 0.11 stable and glad to see the scripts no longer crash at startup, which is great.

    However, I have found the 4PM pro has been struggling to switch the contactors we have reliably.

    9 times out of 10, I have no issues, the shelly buttons trigger it correctly, scrips and switch them and even manually controlling it on the Pro's own screen works fine.

    However I will sometimes get a fault where after switching off the contactors, the Shelly will not switch them back on, even though it displays ON, no wattage is shown and the contactors are not energized.

    The only way I have been able to fix it so far is to reboot the Shelly 4PM Pro, and the contactors are then able to be energized, showing 1.5-2w per contactor.

    Has anyone else had this issue?

    The 2 contactors are on separate channels of the shelly 4pm (single phase) controlling 2 separate banks of LED lamps (20x 150w Lamps and 10x 150w Lamps).

    I noticed more problems switching them all on at the same time, so I have set it up by script instead to switch 1 bank directly, and the other bank checks every 5 seconds then switches them on if demand was requested.

    Again switching off is never an issue, its turning them on.

  • Connecting R/C snubbers across the coils of the contactors may help! Snubbers are available at Shelly shop:

    https://shop.shelly.cloud/rc-snubber-wifi-smart-home-automation

    or at any distributor of electronic parts.

    „Habt Geduld. Alle Dinge sind schwierig, bevor sie einfach werden!“ (aus Frankreich)

    „Nothing in life is to be feared, it is only to be understood.“ (Marie Curie, 1867-1934)

    „Es reicht nicht“, rief Schiller, „Gedankenfreiheit zu fordern, man muß auch denken können, sonst fordert man Gedankenlosigkeitsfreiheit und die ist die Freiheit zur Dummheit, welche wiederum die schlimmste Unfreiheit überhaupt ist!“
    (Aus „Besuch aus Weimar“ von Gert Heidenreich, Schriftsteller, *1944 in Eberswalde)