57
NA11 - Manual - 02 - 2009
FUNCTION CHARACTERISTICS
Fun_50-51S3.ai
I
L1
I
L2
t
>>>RES
T0
RESET
t
>>>def
0T
≥1
≥1
t
>>>def
I
>>>def
t
>>>RES
Start I>>>
Trip I>>>
CB-State
Start I
2ndh>
ON≡Enable 3rd overcurrent element
(Pickup within CLP)
(Pickup outside CLP)
Block1, Block2
&
I>>>TR-K
I>>>TR-L
I>>>ST-L
I>>>ST-K
T0
t
CLP>>>
&
2nd harmonic restraint enable (ON≡Enable)
I>>>2ndh-REST
ICLP>>>Mode
I
CLP
>>>def
t
CLP
>>>
I
L1
≥ I >>>
I
L1
≥ I >>>
BF Enable (ON≡Enable)
I>>>BF
towards BF logic
I>>> BF
&
Trip I >>>
TRIPPING MATRIX
(LED+RELAYS)
A
B
C
A =“1”A =“0 or OFF”
Output t
CLP>>>
I
L3
I>>> Enable
I>>> overcurrent element (50/51) Block diagram
t
CLP>>>
Output t
CLP>>>
CB State CB OPEN CB CLOSED CB OPEN
t
0.1 s
HIGH THRESHOLD/
BLOCK
LOW THRESHOLD/
UNBLOCK
HIGH THRESHOLD/
BLOCK
A = ON - Change setting
B = OFF
C = ON - Element blocking
&
(ON≡
Inhibit
)
Start I>>>
Start I>>>
Start I>>>
(ON≡
Inhibit
)
I> inhibition
I> disbyl>>>
&
I>> inhibition
I>> disbyl>>>
≥1
CLP I>>>
Phase overcurrent (50/51) - Third element logic diagram (I>>>)