The I-Gard mGARD is a microprocessor based ground fault relay designed and built to be used on solidly grounded or resistance grounded systems. This innovative digital electronic relay measures ground fault current using built-in zero sequence current sensor (ZSCS). The mGARD operates on any control voltage from 40-240 volts direct current (DC) or alternating current (AC), and contains an isolated power supply. Options are available for operation at 5 VDC, 12 VDC and 24 VDC.
The mGARD reacts to alternating current only and will reject direct current signals. With the harmonic filtering feature enabled, the mGARD rejects all higher frequencies than fundamental. This can be used to eliminate false tripping when the relay is used on systems with variable frequency drives. With the harmonic filter disabled, the relay will respond to AC currents between 25 and 400Hz. The relay can be connected to the mGARD-SYM remote indicator (with Modbus connectivity) for remote test/reset and monitoring. The mGARD-SYM provides detailed device status information.