Micro850 2080-LC50-48QWB Relay output stuck on

I have L1 from 120 AC wired into the com for the relay outputs 12, 13, 14 and 15. Number 12 and 13 have become permanently stuck on. There is only a light 125XBRIRGA120AB from Edwards signaling hooked to it. I can't imagine this is pulling very much. Why are my relays stuck permanatly closed now. When connected in Connected Components Workbench and go to Global variables and click the Logical value for those ports I see the light on the plc for that port light up but no click. Can switching these too fast on and off break them? I have a Red Lion G304K hooked to it and 2 push buttons on the screen to turn the plc global variable on and off.

What are you controlling with the relays?

If it's an inductive load (coils, solenoids), you could mitigate this problem in the future with surge suppressors on the relay outputs. They prevent inrush current from frying the relay (see page 11)

http://literature.rockwellautomation.com/idc/groups/literature/documents/in/2080-in008_-en-p.pdf

Switching them too quickly could absolutely damage them. I can't find the specs for your specific controller, but the 1734-OW4 (Point/IO Relay Module) is rated for 100,000 cycles, with a minimum switching frequency of 1 operation per 3 seconds.

http://literature.rockwellautomation.com/idc/groups/literature/documents/in/1734-in055_-en-e.pdf

Thanks for the datasheet and writing back. I bring L1 of 120 AC into a common and use the relay to turn on and off 120 to the light that I put the part number of. This light pulls .1 amps. It just seems really hard to believe that is breaking a contact rated to 265 VAC and 5 amps. With that low of draw, shouldn't we not have to worry about much of anything to put across the light for suppression?
From the data sheet I saw the min switch time is 10mSec so they have to be plenty fast compared to my slow couple times a sec the tough screen MIGHT be able to send a open or close signal.
I lost communication on my MCS board across the street at the same time as the relay stuck closed. I notice the datasheet you provided says there is 1 kV TVS protections on signal ports. I wonder if power from the plant is spiking above 250 VAC and hurting the ports as it seems there would be a gap between the 265 VAC and the TVS protection window.
Just seems like a name brand PLC like this shouldn't be breaking the relays with .1 amp draw

Ended up being the inrush current on the light 125XBRI light from Edwards Signaling. It runs at .1 amps but in the installation instructions a guy will find the inrush current of 28.5 amps!!!!! Not quite sure what the max inrush current for the Micro850 or where/IF they spec it but this i am sure is over it.

Even for an incandescent, that sounds crazy high. Time to switch to an LED lamp?

Almost 300 times the operating current..... Engineering failure! Hooked up a light from Banner and boom no problems.

I like how when hooking stuff up "boom" is associated with "no problems".

rupej said:

Even for an incandescent, that sounds crazy high. Time to switch to an LED lamp?

Click to expand...

That is an LED lamp! It must be charging up a cap or something.

28.5 amps for 212 microseconds.

It's likely a strobe rated LED, which will have bigger cap to facilitate a faster strobe rate but comes with a nasty cap charging current, and the one you replaced it with is probably not strobe rated.