The device provides both directional and non-directional overcurrent protection and thermal overload protection, as well as directional and non-directional ground-fault protection. In addition to directional earth-fault protection, the device also supports ground-fault protection based on admittance, harmonic components, or zero-sequence power.
Sensitive earth-fault protection, phase-loss protection, instantaneous/intermittent earth-fault protection, overvoltage and undervoltage protection, zero-sequence overvoltage protection, positive-sequence undervoltage protection, and negative-sequence overvoltage protection are also available.

Includes frequency protection functions such as over-frequency, under-frequency, and rate-of-change-of-frequency (ROCOF). For overhead feeder line applications, the device supports three-phase multi-shot automatic reclosing (AR).

Through optional hardware and software configurations, the device can perform arc-flash protection for the circuit-breaker compartment, busbar compartment, and cable compartment of indoor metal-clad switchgear.
This is achieved using up to three point-to-point lens-type arc-detection sensors. The sensor interfaces are provided on the optional communication module. In the event of an arc-flash fault, the ultra-fast trip command ensures personnel safety and minimizes equipment damage.

When equipped with the optional high-speed output module, the system can further reduce the impact of arc faults.

The REF620 feeder protection and control device provides overcurrent and earth-fault protection for public and industrial distribution networks. It is suitable for isolated-neutral, resistance-grounded, and impedance-grounded systems.
With advanced inter-substation communication, the REF620 can also be applied in ring networks, meshed networks, and radial distribution networks.

REF620 can be used in switchgear with single- or double-busbar configurations, with one or two circuit breakers, and various switching device arrangements. It supports both manual and motor-operated disconnectors and earthing switches, and can be configured in large quantities. The number of controllable devices depends on the available I/O after meeting protection and other functional requirements. The number of virtual outputs (VOs) can be expanded using the RIO600 remote I/O extension unit.

Offers extensive configurability to meet diverse application requirements. PCM600, the configuration and engineering tool for all Relion devices, provides all necessary tools for setting up the RELION series—including function selection, parameter settings, HMI configuration, and communication settings.

REF620 is an ideal solution for advanced feeder protection applications. ABB continues to invest in R&D and collaborates closely with customers to deliver market-leading solutions for ground-fault protection. To further enhance arc-flash protection and reduce the severity of arc faults, REF620 devices equipped with arc-flash options may use a high-speed VO card capable of delivering output signals within 1 millisecond.

ABB REF620 NBFNAANNNDA1BBN1XF｜Feedline Protection Measurement And Control Device｜