Model 77C is a fully programmable electronic overload relay designed to monitor single phase systems. It can be used as a stand alone product or the communication port can be used to form a network and monitor the motors from a laptop or desktop computer; or other control system. Applications include conveyor systems, HVAC equipment, pumps, saws, grinders, and other single phase electric motors.

The Model 77C includes a built-in current transformer (CT) which will handle applications from 2-90 Amps. An external current transformer can be implemented to handle applications up to 700 Amps. The following 15 parameters can be viewed from the three digit alphanumeric LED or from a network computer: low voltage set point, high voltage set point, CT size/Loops setting, over current trip point, under current trip point, trip class (5, 10, 25, 20, 30, or linear), Rapid Cycle Timer (RD1), Overload Restart Delay (RD2), Underload Restart Delay (RD3), number of starts after an overload (manual or automatic), RS485 address, Number of restarts after an underload fault, underload trip delay, linear over current trip delay, restart delay time waits (RD2/RD3). Both the L1-L2 voltage and the line current can also be viewed while the motor is running.

The Model 77C can be used with an optional RS485 module allowing up to 99 Model 77C, Model 777, or Model 601 units to be linked together. From the computer, an operator can control the motor, view the operating parameters, or log information. Software and RS485 module sold separately.