ABB SPAJ140C Combined overcurrent and earth fault relay

Function

- Three-phase, low-setting phase overcurrent device with timed or inverse definite minimum time (IDMT ) characteristics

- Three-phase, high setting phase overcurrent device with instantaneous or timed characteristics

Operation

- Low-level ground fault device with timed or inverse deterministic minimum time (IDMT) characteristics

- High-level ground-fault unit with instantaneous or definite-time operation

- Built-in circuit breaker fault protection

- Two heavy load relays and four signal output relays

- Matrix of output relays for routing the start or trip signals of the protection stage to the desired output relays

- Local display of measured values, set values and data recorded during faults

- Reading and writing of set values via local display and front panel pushbuttons or via the serial interface and fiber optic bus of the higher-level system

- Self-monitoring system for continuous monitoring of electronics and microprocessor operation

Microprocessor operation

- Powerful software support for relay parameterization, reading of measured and logged values, events, etc., and

Powerful software support for relay parameterization, reading of measured and recorded values, events, etc., and storage of readings

- Member of the SPACOM product family and ABB's distribution automation system

- CE marking according to the EU EMC directive

APPLICATIONS

The SPAJ 140 C combined overcurrent and earth fault relay is intended for use on solid earths,

The combined overcurrent and earth fault relay is used for selective short-circuit and earth fault protection of radial feeders in solidly earthed, resistance earthed or impedance earthed power systems.

The integrated relay consists of an overcurrent unit and an earth fault unit with flexible tripping and signaling facilities.

The overcurrent and earth fault relays can also be used for other applications where single, two or three phase overcurrent protection is required.

The SPAJ 140 C combined overcurrent and earth fault relay is part of ABB's distribution automation concept, a complete solution for controlling and managing power systems.

Design

The combined overcurrent and earth fault relay is a secondary relay connected to the current transformer of the protected object.

The current transformer of the The three-phase overcurrent and earth fault device continuously measures the phase and neutral currents of the object.

When a fault is detected, the relay activates and trips circuit breakers, provides alarm signals, and records fault data according to the application requirements and relay configuration.

The overcurrent device activates when the phase current exceeds the set start current of the low setting level I> and sends out a start signal after a preset start time.

In timed operation, the overcurrent device starts when the set run time or in inverse time limit operation, when the calculated run time has elapsed.

Similarly, when the set starting current is exceeded, the high level stage I>> of the overcurrent device is activated and a start signal is issued after the preset (~40 ms) start time.

When the set operation time has expired, the overcurrent device starts.

The ground-fault unit starts when the ground-fault current exceeds the set start current of the low setting level I0>> and

and sends a start signal after the earth fault current exceeds the set start current of the lower setting level I0>.

The earth fault unit starts and signals a start after the preset start time. After the set operating time (timed operation) or the calculated operating time (counterclockwise operation) has elapsed, the

The ground fault unit starts operation. Similarly, when the set start current is exceeded, the ground-fault unit's high level stage I0>> starts up

and sends a start signal after a preset (~50 ms) start time. As soon as the set operation time has expired, the ground fault unit starts to operate.