P&C Timing Diagram

Fault Occurs Near TS - I.e; High Ground Current

50A Picks Up - High Set

0 - 1

16ms

Fault Occurs

0

Transfer Trip Sent to DG & GT Breakers

1 - 3

M2 Breaker Trips - Contacts Begin to Part

1 - 6

Downstream Breakers Operate - Contacts Begin to Part

3 - 6

DGEO is Sent to 50A

6 - 8

M2 Reclosing Initiated (Dependent on if DGEO was Received)

8 - 13

51 Picks Up & Locks Out System (If Fault Persists)

13

Fault Occurs Many Km Downstream of TS - I.e; Low Ground I

50B Picks Up - Low Set

0 - 1

Fault Occurs

0

Transfer Trip Sent to DG & GT Breakers

1 - 3

50ms Delay Initiated for Trip to M2 Breaker

1 - 4

Downstream Breakers Operate - Contacts Begin to Part

3 - 6

Delay Ends, M2 Breaker Trips - Contacts Begin to Part

4 - 9

DGEO is Sent to 50B

6 - 8

M2 Reclosing Initiated (Dependent on if DGEO was Received)

9 - 14

51 Picks Up & Locks Out System (If Fault Persists)

14