Not active product since 2009
The numerical feeder protection relay SPAA 121 C is used for selective short-circuit and earth-fault protection of radial distribution networks. The feeder protection relay is an integrated device incorporating a two-phase phase overcurrent unit and a directional neutral overcurrent unit in one relay. Further, the feeder protection relay incorporates circuit-breaker failure protection.
When 1 A or 5 A current transformers are used for both the overcurrent unit and the earth-fault unit the feeder protection relay SPAA 120 C is recommended. The feeder protection relays SPAA 120 C and SPAA 121 C have identical functions. The only difference between the two relays is the rated current of the earth-fault relay units, i.e. 1 A and 5 A for the relay SPAA 120 C and 0.2 A and 1 A for the relay SPAA 121 C.
Scope
- Selective short-circuit and earth-fault protection of radial distribution networks
Product benefits
- Multi-functional protection functions
Product features
- Two-phase low-set phase overcurrent unit with definite time or inverse time characteristic
- Two-phase high-set phase overcurrent unit with instantaneous or delayed operation
- Sensitive directional low-set neutral overcurrent unit with definite time characteristic
- Directional or non-directional high-set neutral overcurrent unit with instantaneous operation
- Four standardized inverse time curves according to IEC and BS and two additional special type curves
- Integrated circuit-breaker failure protection with adjustable operate time
- Numerical display of setting values, measured values, values recorded in fault situations, etc
- Sophisticated self-supervision system with auto-diagnostic features
- Member of the SPACOM product family and ABB’s Substation Automation system
- CE marking according to the EC directive for EMC