Is this a faulty output module?

I have a 12-channel VF relay module thats been in service and working for a little over 12 months. It's a low-use module, most outputs toggling once or twice a day and not much more.

Over the last month, one output only (ch 12) has taken to turning itself OFF almost immediately it's turned on.

In its application, all outputs are normally off and turn on for a minute or so. Channels 1-11 are behaving properly, only channel 12 is misbehaving.

Well, in toolkit last night, I set it to "flash" the output every 5 seconds and went and watched the output module. The Ch12 light came on and the relay came on with an audible click. Anything from a few hundred milliseconds to a second or two later, the relay would click off again - but the LED indicating the channel was on, remained on until the end of the 5 seconds.

I've checked, and the "ALL ON" and "ALL OFF" connections are disconnected (open circuit).

I've also monitored with toolkit, and nothing is *turning the channel off*.
I even created a new, unused group and reassigned channel 12 to that group - the problem remains with channel 12.

I realise the relays are magnetic latching relays - which means it must be *TURNED OFF*, and isn't just a bad connection making it drop out (or am I mistaken about that assumption?).

Anyone got any more useful tests I can do, or encoutered the same thing?

Oh, after a while "exercising" yesterday (cycling on and off) it's come good for now - but it did this once before - when I started looking for the problem it went away - for 10 days odd, before it came back!

Thanks,
RossW

 

This is almost certainly a hardware fault with the unit, so you're not losing your mind. If it's still under warranty you should return it for repair.

If you can see inside the unit, are the relays themselves white or orange?

 

Ahhh. Thanks.

They're white, with green screen-printing on the side from what I can see, peering in through the ventilation slots. Does that tell you something significant? It has a Manfactured data of 2006, but I've only had it a while.

 

It just gives me a rough indication of when the unit was made and which relays it is using.