I have an IP2CC that has a closure (CC 1:3) that has failed closed. The other two contact closures work fine, but the 3rd one will not open the circuit any longer. I've tried swapping circuits with the other closures and it's definitely a problem with this one contact closure. I'm using it to control 24v DC flowing to a high voltage relay. Perhaps the relay sent a voltage spike out onto the circuit? Does anyone have any experience wiring a CC up in this manner? Should I be including my own IN4003 or similar diode across the circuit to protect the IP2CC against voltage kickback from the relay? I was kind of expecting that the IP2CC would have its own protection circuitry against this kind of thing. Any other ideas why the contact would fail closed?
IP2CC contact closure circuit protection?