ABB REX521GHHGSH51G Feeder protection relay REX 521

When the relay uses the RS-485 bus for the serial communication, both two- and four wire connections are supported.

Termination and pull-up/down resistors can be configured with jumpers on the communication card so external resistors are not needed.

The relay supports the following time synchronization methods with a time-stamping resolution of 1 ms.

REC670 IEDs (Intelligent Electronic Device) provide control solutions for any type of switchgear and different switchgear configurations. 

The customized REC670 gives you the freedom to select the functionality entirely according to your needs. 

The protection functions also support different types of networks, such as, isolated neutral networks, 

resonant-earthed networks and partially earthed networks. 

Ethernet-based

• SNTP (Simple Network Time Protocol) With special time synchronization wiring

• IRIG-B (Inter-Range Instrumentation Group - Time Code Format B)

The relay supports the following high accuracy time synchronization method with a time-stamping

resolution of 4 µs required especially in process bus applications.

• PTP (IEEE 1588) v2 with Power Profile

The IEEE 1588 support is included in all variants having a redundant Ethernet communication module.

IEEE 1588 v2 features

• Ordinary Clock with Best Master Clock algorithm

• One-step Transparent Clock for Ethernet ring topology

• 1588 v2 Power Profile

• Receive (slave): 1-step/2-step

• Transmit (master): 1-step

• Layer 2 mapping

• Peer to peer delay calculation

• Multicast operation

Required accuracy of grandmaster clock is +/-1 µs. 

The relay can work as a master clock per BMC algorithm if the external grandmaster clock is not available for short term.

The IEEE 1588 support is included in all variants having a redundant Ethernet communication module.

In addition, the relay supports time synchronization via Modbus, DNP3 and IEC 60870-5-103 serial communication protocols.

615 series supports Profibus DPV1 with support of SPA-ZC 302 Profibus adapter. 

If Profibus is required the relay must be ordered with Modbus serial options. 

Modbus implementation includes SPA-protocol emulation functionality. 

This functionality enables connection to SPA-ZC 302.

The application area also covers medium-sized three phase asynchronous motors as well as 

protection and control of shunt capacitor banks used for reactive power compensation. 

In addition to protection, measurement, control, condition monitoring and general functions,

the REF 543 feeder terminals are provided with a large amount of PLC functions, 

which allow for several automation and sequence logic functions, needed for substation automation, to be integrated into one unit.

The pre-configured REC670 variants simplify handling since the basic functionality is included and pre-configured. 

If needed, you can add optional functions to easily increase the functionality of 

the REC670 IEDs to meet the specific requirements of your switchyard.