Siemens Relay Module Problems

[JayC 0]

Hello all, Just wondering if anyone has ever used the Siemens 16PT Relay Output module (6ES7322-1HH01-0AA0) for any applications? It was used to drive 24VDC solenoid valves and motor contactor coils in a certain applications. The module says it is good for 2A @24VDC and the equipment was tested to have a max load of ~1.2A @ 24VDC usually ranging in the 0.8A range. However, we are having problems with these modules failing very frequently. I realize these relays are not going to last forever, but at the same time they are failing as soon as a couple of weeks after being installed. I was just wondering if anyone has ever used this module before, and if so, in a similar application without problems?

[Berg 0]

Hi JayC, I think the problem is the current peak when you turn on the coil of the solenoid. For a little moment the current is 3 to 7 times the nominal current. So, when I had this problem I changed the modules to transistors and in the outputs of them I've connected standard relays (6 - 10 A) to turn on the solenoids and the problem disappeared. I hope I've helped you ! Best regards, Berg