I think I have had a total of 2 CP3s over the years where all the relays just stopped working.? None on the AV3/PRO3 although we haven't sold near as many of those.? So over the 10 years or so that the Series 3? has been in production, I would not consider that a high failure rate.
But for something like gate control, I always surge protect the relay contacts by going through something like the phone line surge protector on many surge protector.? On the whole, Crestron products, as with most other vendors, have absolutely no surge protection for the voltages you will see when there is a lightning strike nearby.? While a relay contact itself has isolation, it is very easy for them to arc over during a lightning hit and damage some the circuitry near by on the PCB.
