SPAD346C

The stabilized differential relay SPAD 346 C is designed for protecting two-winding power transformers and generator-transformer. The main features include protection for winding short-circuits, interturn faults, earth faults and short circuits, as well as interwinding short-circuits and pole short circuits. In addition, the relay can be used for protection of three-winding power transformers, provided that 75% of the short circuit power to the power transformer is supplied from the same direction.

Integrated three-phase differential relay, three-phase overcurrent relay and multi-configurable earth-fault protection

Integrated three-phase differential relay, three-phase overcurrent relay and multi-configurable earth-fault relay
Three-stage overcurrent module providing protection for power transformers and generators and two-stage backup earth-fault protection
Stabilized against unwanted operations at faults occurring outside the protected area and at transformer inrush
Second harmonic restraint for prevention of unwanted relay operations at transformer inrush
Fifth harmonic restraint for prevention of unwanted relay operations at transformer overexcitation
Wide CT ratio correction range – accurate correction through digital setting
Four heavy-duty output relays for circuit breaker tripping and five output relays for signalling
Five programmable external control inputs
Integrated circuit breaker failure protection with adjustable operate time
Differential relay and earth-fault relay modules with integrated disturbance recorder functions for analog and digital signals
Sensitive phase current and phase angle displays facilitate checking of energizing circuit connections and vector group matchings
High immunity to electrical and electromagnetic interference allows the relay to be used in severe environments
High availability and system reliability due to continuous supervision of hardware and software
SPAD346C