Direct Control of Motor Contactors via PLCs and Distributive Control Systems

07/01/2008
As we automate the process systems more and more, we are looking for direct control of the motor starters with PLCs and Distributive Control Systems (DCS). A commonly asked question is whether or not the interposing relay situated between the two systems is really needed. I have gone through and looked at the more common systems and put together this technical brief to highlight some of the concerns involving the interposing relay.