Voltage Frequency Protection Relay

RD7 - RD9 ELR

Earth Leakage ELR & Ground Fault Relay

The Earth Leakage Relay RD is a microprocessor-based electronic protection device designed to detect low-level current leakage.

The RD series allows preventative control of the system's insulation with continuous displaying of the earth leakage current obtained by the use of a ring-type current transformer. Modbus communication is available.



Functionality

• Digital display of earth-leakage current in Ampere or in percentage of Trip level.
• Independent Current adjustments for alarm and tripping from 30 mA to 10 A.
• Independent Time adjustments for alarm and tripping, from 0.03 to 5 Sec.
• 2 Output relays: TRIP and ALARM, “latch” or “pulse” mode.
• Service function (Alarm relay).
• Indication and storage of the maximum fault current in a non-volatile memory.
• Manual or automatic reset. The automatic reset is lockout after 3 automatic operations in a period of time less than 9 minutes.
• Check of output relays and leds.
• Continuous control of CT wiring connection.
• High immunity to external disturbances and harmonic current components.
• Its function is also guaranteed with alternate sinusoidal and continually pulsing currents.
• Menu on the frontal panel.

Protection

Current transformers