Auto-Reclose and Check Synchronising
General Information
- Description
Automatic circuit reclosing is extensively applied to overhead line circuits where a high percentage of faults that occur are transient in nature. Automatic reclosing of the circuit breaker attempts to minimise the loss of supply to the customer and reduce the need for manual intervention.
Check synchronising ensures that a circuit breaker can only be closed when the voltages and frequency of the power system on each side of that circuit breaker are within acceptable limits.
Our Portfolio (3)
- Description
- Function overview
- Features
7SG117 relays monitor the voltage on each side of a circuit breaker (CB). The relay issues a permissive signal when both voltages within allowable limits to permit CB closure e.g. phase angle, voltage magnitude, frequency difference.
7SG117 relays are applied in manual closing or auto-reclosing schemes where conditions of system synchronism must be checked prior to CB closure.
Relays have two voltage imputs and are housed in E4 cases.
Integrated logic is provided to allow the optimal configuration of relay functionality with the relays analogue inputs and binary input/output circuits.
Protection and instrumentation functionality is accessible via the data comms channel - a fibre optic or RS485 port is provided on the rear of the relay.
Supervision Functions
- Split system detection
- Check/system synchronising
Control Functions
- Under voltage blocking
- Differential blocking
- Dead bus / dead line charge
- Password Protection
- Self Monitoring
- Fault, event and waveform records
- Event and waveform records