We have a customer that has had several output relays fail on multiple CP1L/H units.

Loads are typically small solenoid valves, well within the specs on the relay.

Has anyone else experienced any failures?

Thanks,
gtsuport

Small selenoids...but inductive load, and maybe theses selenoids are energized very frequently.
You should use "snubber" in parralel with the load. You can make them but you can buy them ready for use.

I never use relay output cards. Use a transistor output card with external relays - currently using G2RV.

Keep in mind this only applies to DC loads. Changes are it is DC when output relays fail. DC loads create more of an arc then AC loads, especially when switched off.

For DC inductive loads (solenoids) you should use a free wheeling diode in parallel with the coil to disipate the back emf.

Arjan, it apply to AC selenoid, too.
In the post #2 of this topic there is what Omron suggest for both, AC and DC. That was copy-pasted from an Omron Operation Manual.
The one with the red circle is for AC selenoid, and below that it is for DC and, as suggested by Sleepy, there is a diode in parralel with the coil.

Using snubbers or diodes for suppression is a good idea for this problem generally.

To answer your question directly... yes, I've seen this more with the CP1L units where I haven't (as much or as often) with the older Omron units such as the CPM units.

Sorry about that, I guess it does. I always use diodes on DC applications, but never bothered with ac circuits. I do feel that DC, at a give voltage, draws more of an arc then ac does.

PLCs with transistor outputs are especially susceptible to burn out when a diode is not used.

I heard about trouble with CP1L relay outputs, but with exceptionally low loads on the relays.
It was some thing that the relay contacts get dirty by the time. So maybe a resistor parallel to the load might help in this case as well
or use of transistor outputs