5 Replies Latest reply on Jun 15, 2018 5:48 PM by mcb1

    Normally Closed  Relay never Opens


      Hello,   I purchased a SS relay Crydom DC60S3-B .   I intended to use it to power a cell modem (12 volt) and need it to be normally closed, so the modem always has power.    To save power, a program controlled data logger would apply 5 volts to the relay control when the modem wasn't needed to be on.  This configuration allows me to connect to the data logger through the modem, and if changes are made to the data logger program, power is Normally applied to the modem and the connection is not lost.    The problem is that the relay doesn't seem to ever be in a open condition.     My data logger program applies 5 volts to the relay input, but power output (12 V) is still going out across the relay.  The actual voltage does drop(dropped 12.8 to 12.6 volts), but does not turn off.      Is this the wrong relay for this application?