Schweitzer Engineering SEL-351P - Timer Settings; EBLKD - Echo Block Delay; EDURD - Echo Duration; ETDPU - Echo Time Delay Pickup

5-14 Trip and Target Logic Date Code 990215
SEL-351P Manual Técnico
Also note that SEL OGIC Control Equation setting PT1 in Figure SECTION 5: .7 is routed to
control Relay Word bit PTRX if enable setting ECOMM = POTT. Relay Word bit PTRX is then
the permissive trip receive input into the trip logic in
Figure SECTION 5: .1.
Timer Settings
See Section 9: Setting the SEL-351P Recloser Control for setting ranges.
Z3RBD – Zone (Level) 3 Reverse Block Delay
Current-reversal guard timer – typically set at 5 cycles.
EBLKD – Echo Block Delay
Prevents echoing of received PT for settable delay after dropout of local permissive elements in
trip setting TRCOMM – typically set at 10 cycles. Set to OFF to defeat EBLKD.
ETDPU – Echo Time Delay Pickup
Sets minimum time requirement for received PT, before echo begins – typically set at 2 cycles.
Set to OFF for no echo.
EDURD – Echo Duration
Limits echo duration, to prevent channel lockup – typically set at 3.5 cycles.
Logic Outputs
The following logic outputs can be tested by assigning them to output contacts. See Output
Contacts in Section 7: Inputs, Outputs, Timers, and Other Control Logic for more information
on output contacts.
Z3RB – Zone (Level) 3 Reverse Block
Current-reversal guard asserted (operates as an input into the trip logic in
Figure SECTION 5: .1
and the DCUB logic in
Figure SECTION 5: .10).
ECTT – Echo Conversion to Trip
PT received, converted to a trip condition for a Weak-Infeed Condition (operates as an input into
the trip logic in
Figure SECTION 5: .1).
KEY – Key Permissive Trip
Signals communications equipment to transmit permissive trip. For example, SEL
OGIC Control
Equation setting OUT105 is set:
OUT105 = KEY