FUNCTION CHARACTERISTICS
49
NA10 - Manual - 04 - 2022
Fun_50-51S1.ai
I
L1
I
L2
t
>RES
T0
RESET
t
>
0T
≥ 1
≥ 1
t
>def
I
>def
I
>inv
t
>inv
t
>RES
Start I>
Trip I>
CB-State
Start I
2ndh>
ON≡ Inhibit (from I>> and/or I>>> overcurrent element)
ON≡ Enable I> overcurrent element
(Pickup within CLP)
(Pickup outside CLP)
I> inhibition
Block1, Block2
&
T 0
t
CLP>
&
2nd harmonic restraint enable (ON≡ Enable)
I>2ndh-REST
ICLP>Mode
I
CLP
>def
t
CLP
>
I
CLP
>inv
I
L1
≥
I>
I
L1
≥
I>
BF Enable (ON≡ Enable)
I>BF
towards BF logic
I> BF
&
Trip I>
TRIPPING MATRIX
(LED+RELAYS)
I> Curve
0T
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>
CB State CB OPEN CB CLOSED CB OPEN
Output t
CLP>
t
0.1 s
HIGH THRESHOLD/
BLOCK
LOW THRESHOLD/
UNBLOCK
HIGH THRESHOLD/
BLOCK
A = ON - Change setting
B = OFF
C = ON - Element blocking
I>TR-K
I>TR-L
I>ST-L
I>ST-K
≥ 1
CLP I>
Phase overcurrent (50/51) - First element logic diagram (I>)