OCV MAN

This is true however I have had more relays fail in systems than triacs over the years. The systems were designed to insure outputs were not above 30% of device spec. I mostly used zero crossing circuit to produce the least amount of noise and interferance. Some of my circuit have been working over 10 years without any failure. However relays have had to be replaced about every 5-6 years. Mostly due to contact burnishing or breakage. Thank You for your reply

I have the concern that most relay outputs have a life time limit of transistion. Why doesn't Unitronics offer a Triac output on there controllers. I curently use 3 different V120 models and two different V350 Model Controllers for systems we make. We are currently using two relay outputs to turn on and off two solenoids (one for opening and one for closing a device) at different rates the closer we get to setpoint the quicker we open or close the solenoid. With the limited life of contact switchings I am concered that we will start seeing relay failure where a triac output will not have this limit. I would suggest a at least two opto-isolated triac with a 2-3amp at 480VAC operational rating. I feel this would be best for most cases. our solenoid range from 6-16 Watts 24, 115, 230VAC. Please advise I have found a Crydom P/N MP240D3 Solid state relay that is almost is the same size as the Current Relay used in the V120 and V350 Controllers.