Schweitzer Engineering Laboratories SEL-351 - Page 185

Date Code 20001006 Trip and Target Logic iii
SEL-351 Instruction Manual
TABLES
Table 5.1: SEL-351 Relay Front-Panel Target LED Definitions.......................................................5-29
FIGURES
Figure 5.1: Trip Logic........................................................................................................................5-2
Figure 5.2: Minimum Trip Duration Timer Operation (See Bottom of Figure 5.1) ...............................5-3
Figure 5.3: Three-Pole Open Logic (Top) and Switch-Onto-Fault Logic (Bottom) ...............................5-8
Figure 5.4: Communications-Assisted Tripping Scheme....................................................................5-11
Figure 5.5: Permissive Input Logic Routing to POTT Logic..............................................................5-15
Figure 5.6: POTT Logic...................................................................................................................5-17
Figure 5.7: Permissive Input Logic Routing to Trip Logic.................................................................5-18
Figure 5.8: SEL-351 Relay Connections to Communications Equipment for a Two-Terminal
Line POTT Scheme (Model 0351xT Example)..........................................................5-19
Figure 5.9: SEL-351 Relay Connections to Communications Equipment for a Three-Terminal
Line POTT Scheme (Model 0351xT Example)..........................................................5-19
Figure 5.10: DCUB Logic ..................................................................................................................5-22
Figure 5.11: Unblocking Block Logic Routing to Trip Logic ...............................................................5-23
Figure 5.12: SEL-351 Relay Connections to Communications Equipment for a Two-Terminal
Line DCUB Scheme (Setting ECOMM = DCUB1); Model 0351xT Example............5-23
Figure 5.13: SEL-351 Relay Connections to Communications Equipment for a Three-Terminal
Line DCUB Scheme (Setting ECOMM = DCUB2); Model 0351xT Example............5-24
Figure 5.14: DCB Logic.....................................................................................................................5-27
Figure 5.15: SEL-351 Relay Connections to Communications Equipment for a Two-Terminal
Line DCB Scheme (Model 0351xT Example)............................................................5-28
Figure 5.16: SEL-351 Relay Connections to Communications Equipment for a Three-Terminal
Line DCB Scheme (Model 0351xT Example)............................................................5-28
Figure 5.17: Seal-in of Breaker Failure Occurrence for Message Display ............................................5-33
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