Logic Control
Sensing and Monitoring Relays
Current Sensing Relays - The AC current relay senses a preset current value and operates a SPDT relay whose contacts may
be used in a control circuit. Unlike apparatus intended for motor or branch circuit protection, the current relay
provides a continuously adjustable trip-current setting.
Resistance Sensing Relays - Type TF and TH Transistorized Relays are resistance sensitive devices. Operation of the
output or control relay occurs when the resistance in the sensing circuit is low enough to permit transistor
conduction.
Voltage Sensing Relays - The VSR voltage sensing relays are highly accurate,solid-state, AC voltage sensing devices
available in both overvoltage and undervoltage types.They include built-in locking shaft potentiometers for voltage and
differential adjustment.