Application 

The REF601 and REJ601 are protection relays aimed at protection and control of incoming and outgoing feeders in MV distribution substations.

They can be applied for short-circuit, overcurrent and ground-fault protection of

overhead lines and cable feeders of distribution and sub-distribution networks.

The inrush current stabilization function allows the relays to be

used as the main protection for distribution transformers.

The relay with application www.abb-drive.com configuration B offers non-directional

overcurrent and ground-fault protection. The residual current for

the ground-fault protection is derived from the phase currents.

When applicable, core-balance current transformers can be

used for measuring the residual current, especially when sensitive ground-fault protection is required.

The application configuration C adds thermal overload protection for feeders, cables and transformers, phase discontinuity

protection and circuit breaker failure protection.

The application configuration D provides the highest functionality with incorporation of negative

phase sequence protection and a multi-shot auto-recloser function making the relay suitable for overhead line feeders.

Optimized for limited space

With their compact size and unique technical features, the

REF601 and REJ601 are ideal for retrofits, compact switchgear

and switchgear with limited space. These relays have a small

mounting depth and do not have any loose mounting accessories.

Uniquely, the REF601 and REJ601 use a press-fit mounting

arrangement, suitable for quick and easy installation on switchgear

Control 

The REF601 features control of one circuit breaker with dedicated push-buttons and guidance on local HMI for opening and closing.

It includes two dedicated outputs for breaker control.

The breaker control is also possible through optional MODBUS RTU or IEC 60870-5-103 communication.

Measurement 

All versions of the relay continuously measure phase currents

and ground current. Ground current can be measured using an

external zero sequence current transformer or can be calculated internally.

During operation, the default view of display shows the highest

loaded phase current in primary terms (Amps) and the ground current.

The values measured can be accessed locally via the

user interface on the relay or remotely via the communication interface of the relay.

These relays continuously measure negative sequence current,

thermal level and counter values if these functions are supported as per application configurations.