The protection relay provides a number of binary outputs used for tripping, executing local or remote control actions of a breaker or a disconnector, and for connecting the protection relay to external annunciation equipment for indicating, signaling and recording. The contacts used for external signaling, recording, and indicating the signal outputs need to adjust to smaller currents but they can require a minimum current (burden) to ensure a guaranteed operation.
The binary outputs are implemented by software-controlled mechanical relays. At power-up (cold boot), all relays are OFF through power-on reset of the microcontroller. In case of a warm boot, the relays remain in the state they are. They can be forced into OFF state by activating the RESET of the micro-controller. The micro-controller controls the relays through logic control lines. To improve robustness, control and switching functions in the relay driver are double mainly to prevent a single error from tripping the binary output relay. All contacts are freely programmable, except for the internal fault output IRF.
Description | Value |
|---|---|
Rated voltage | 250 V AC/DC |
Continuous contact carry | 5 A |
Make and carry for 3.0 s | 10 A (normal BO) and 15 A (SO1 type) |
Make and carry for 0.5 s | 15 A/30 A (SO1 type) |
Breaking capacity when the control-circuit time constant L/R <40 ms, at 48/110/220 V DC | IEC: 1 A/0.25 A/0.15 A UL: According to component manufacturer’s claim |
Contact operating time | <7 ms |
Channel to channel isolation | BOs shall be isolated from each other so that they can be connected freely to external potentials. |