sepam 20 user manual - Schneider Electric

Protection functions Recloser
ANSI code 79
PCRED301005EN - 06/2008
Operation
Initialization of the recloser
The recloser is ready to operate if all of the following conditions are met:
b "CB control" function activated and recloser in service
b circuit breaker closed
b inhibition time delay not running
b none of the recloser inhibition conditions is true (see further on).
Recloser cycles
b case of a cleared fault:
v following a reclosing order, if the fault does not appear after the memory time delay
has run out, the recloser reinitializes and a message appears on the display (see
example 1)
b case of a fault that is not cleared:
v following instantaneous or time-delayed tripping by the protection unit, activation
of the isolation time delay associated with the first active cycle.
At the end of the time delay, a closing order is given, which activates the memory time
delay.
If the protection unit detects the fault before the end of the time delay, a tripping order
is given and the following reclosing cycle is activated.
v after all the active cycles have been run, if the fault still persists, a final trip order
is given, a message appears on the display and closing is locked out until
acknowledgment takes place, according to the parameter setting of the protection
function
b closing on a fault.
If the circuit breaker closes on a fault, or if the fault appears before the end of the
lockout time delay, the recloser is inhibited.
Recloser inhibition conditions
The recloser is inhibited according to the following conditions:
b voluntary open or close order
b recloser put out of service
b receipt of a lockout order on the lockout logic input I26
b appearance of a switchgear-related fault, such as trip circuit fault, or unexecture
control order fault
b opening of the circuit breaker by external tripping via inputs I21, I22 or I23.
Characteristics
Reclosing cycles Setting
Number of cycles 1 to 4
Activation of cycle 1 (1) overcurrent 1 inst. / delayed / inactive
overcurrent 2 inst. / delayed / inactive
earth fault 1 inst. / delayed / inactive
earth fault 2 inst. / delayed / inactive
Activation of cycles 2, 3 and 4 (1) overcurrent 1 inst. / delayed / inactive
overcurrent 2 inst. / delayed / inactive
earth fault 1 inst. / delayed / inactive
Time delays
earth fault 2 inst. / delayed / inactive
Memory time delay 0.05 to 300 s
Isolation time delay cycle 1 0.05 to 300 s
cycle 2 0.05 to 300 s
cycle 3 0.05 to 300 s
cycle 4 0.05 to 300 s
Lockout time delay 0.05 to 300 s
Accuracy ±2 % or 25 ms
Resolution 10 ms or 1 digit
(1) If a protection function that is inactive in relation to the recloser leads to circuit breaker
opening, the recloser is inhibited.
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