NK Technologies released a new AGV Series Ground Fault Relay with the ability to detect faults to earth on the load side of a variable frequency drive. This unique capability addresses a challenge caused by the carrier or switching frequency of the drive. Typically, 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. In comparison, the AGV will trip at a fraction of the motor’s full load current. Its design allows the sensor to trip at a choice of 30, 50, or 100 mA to current to earth.
AGV ground fault relay applications include protecting equipment and processes from damage due to ground fault conditions by monitoring all current-carrying conductors in grounded single- and three-phase delta or wye systems.
AGV Series highlights include:
Broad range of options to match specific application requirements
- N.O./N.C. mechanical relay outputs
- Normally energized or normally de-energized contacts
- Latching or automatically resetting output available
Setpoint options to maximize ease of use
- Field-selectable 30 mA, 50 mA, or 100 mA setpoints
Compatible with standard equipment
- Applicable on single- and three-phase systems
- Ideal for use with shunt trip breakers or contactor coil
- Electrically isolated from monitored circuit and control power
Designed for UL/cUL and CE Approval (accepted worldwide). For more information, visit nktechnologies.com.
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Filed Under: Drives (ac) + VFDs + starters, Power supplies, Terminal blocks