Over-current and earth-fault relay SPAJ 140 C

Description

The combined overcurrent and earth-fault relay SPAJ 140 C is intended to be used for the selective short-circuit and earth-fault protection of radial feeders in solidly earthed, resistance earthed or impedance earthed power systems. The integrated protection relay includes a phase overcurrent unit and an earth-fault unit with flexible tripping and signalling facilities. The overcurrent and earth-fault relays can also be used in other applications requiring single-, two- or three-phase overcurrent protection and non-directional earth-fault protection. The combined overcurrent and earth-fault relay also features circuit breaker failure protection.

Product benefits

• The most commonly used numerical protection relay on the market

Product features

• Easy-to-use relay with the most essential functions for over-current and earth fault protection
• Proven technology
• Three-phase, low-set phase overcurrent unit with definite time or inverse definite minimum time (IDMT) characteristic
• Three-phase, high-set phase overcurrent unit with instantaneous or definite time operation
• Low-set earth-fault unit with definite time or inverse definite minimum time (IDMT) characteristic
• High-set earth-fault unit with instantaneous or definite time operation
• Built-in circuit-breaker failure protection
• Self-supervision system continuously monitoring the operation of the electronics and the microprocessor