ABB REF610 Feeder Line Protection Relay Product Applications

4. Applications

The REF610 is a multifunctional relay designed primarily for the protection

of incoming and outgoing lines in medium voltage distribution substations.

In industrial and utility applications, the relay can also be used as backup protection for motors, transformers and generators.

The relay incorporates a number of protection features including three levels of overcurrent protection,

two levels of non-directional ground fault protection and thermal protection to provide comprehensive overcurrent and ground fault protection.

An optional arc protection function can be used to detect arcing conditions in air-insulated metal-clad switchgear,

and an automatic reclosing function can be used to automatically clear overhead line faults.

These features further expand the range of applications for the relays.

The large number of digital input and output contacts allows a wide range of applications.

4.1. Requirements

To ensure correct and safe operation of the relays, it is recommended that preventive

maintenance be carried out every five years on relays operating under specified conditions;

See table 4.1.-1 and section 5.2.4. Technical Data.

When used for real-time clock or logging data functions, the batteries should be replaced every five years.

4.2. Configuration

By appropriately configuring the output contact matrix, signals from the protection

level can be used as contact functions. The start signals can be used for

for blocking cooperating relays and for signaling.

The following figure shows the default configuration of the relay: all trip signals are routed to trip the circuit breaker.

In the first example in Figure 4.2.-1. the residual current is measured by

the iron core balancing current transformer and the output contacts are connected to enable the automatic reclosing function.

In the second example in Figure 4.2.-2. the residual current is measured through

the trimming connection of the phase current transformer and the output contacts are connected

to enable the trip lockout function with an external reset switch.