NK AGV3-SDT-120-DEN-TR3 - AGV Series Ground Fault Relay

AGV Ground Fault Relay

AGV Series Ground Fault Relay helps protect products and processes from damage caused by ground fault conditions by monitoring all current-carrying conductors in grounded single- and three-phase delta or wye circuits.

The AGV series has the unique ability to detect faults to earth on the load side of a variable frequency drive. The carrier or switching frequency of the drive presents a difficult challenge: The fault current will be detected at the base frequency, which determines the motor speed. While many Variable Frequency Drives have ground fault detection built-in, the detection level is the same as the overcurrent limit. That approach will shut down the drive but only after considerable damage to the motor has occurred.

The output contact action can be selected as auto-reset for applications to control a shunt trip breaker or latching for applications to de-energize a contactor coil when a fault occurs.

Ground Fault Relay Features

Broad Range of Options to Match Application Needs

• N.O./N.C. mechanical relay outputs
• Normally energized or normally de-energized contacts
• Latching or automatically resetting outputs available

Setpoint Options Maximize Ease-of-Use

• Field-selectable 30 mA, 50 mA, or 100 mA setpoints makes user adjustments fast, sure and convenient

Compatible with Standard Equipment

• Applicable on single- and three-phase systems
• Ideal for use with shunt trip breakers or contactor coils
• Electrically isolated from monitored circuit and control power

Designed for UL/cUL and CE Approval

• Accepted worldwide

Latching Models (-LA Option)

From factory, power up initially in the reset (normal) mode. If there is a fault condition or the test button is pushed, the output contacts will change state and latch. The output will remain latched regardless of whether the fault is cleared, or control power is removed. To reset the output, apply a momentary contact across “reset” terminals. Do not apply voltage to reset terminals.

"Zero Sum" Operating Principle:

In single- and three-phase AC systems, under normal conditions current flows from the power source to the load and back to the source. As a result, the electromagnetic field surrounding the conductors cancel, producing a "zero sum current" even when the current in each phase are not equal. As soon as current leaks to ground (fault condition) the current become imbalanced and a net magnetic field results. AGV Series detectors monitor this field and trip alarm contacts when the leakage rises above the setpoint.

Ground Fault Relay Ordering Information

Sample Model Number: AGV3-SDT-120-LA-TR3
Ground fault detector with SPDT latching relay output, 120 VAC power supply and 30/50/100 mA trip point.