Thytronic NA20, Manual, Page: 52 / 208

FUNCTION CHARACTERISTICS
52 NA20 - Manual - 04 - 2022
46S1-diagram.ai
I
2
t
2>RES
T 0
RESET
t
2
>
0 T
≥ 1
t
2>def
t
2>inv
t
2>RES
Start I2>
Trip I2>
ON ≡ Inhibit (from I2>> element)
ON ≡ Enable I2> overcurrent element
(Pickup within CLP)
(Pickup outside CLP)
I2> inhibition
&
I2CLP>Mode
I
2CLP>def
I
2CLP>inv
I
2
≥ I
2CLP
>
def (inv)
BF Enable (ON ≡ Enable)
I2>BF
towards BF logic
I2> BF &
Trip I2>
TR
IP
PIN
G
M
AT
RIX
(
LE
D+R
EL
AY
S)
I
2
> Curve
0 T
I2> Enable
I2> Negative sequence overcurrent element (46) block diagram
Output t
2CLP>
t
2CLP
>
Output t
2CLP>
I2>TR-K
I2>TR-L
I2>ST-L
I2>ST-K
I
2
>
inv
I
2
≥ I
2
>
def
I
2
≥ I
2
>
inv
I
2
>
def
Negative sequence overcurrent (46) - Logic diagram of the first threshold (I2>)
T 0
t
2CLP
>
t
2CLP
>
Block1, Block2
A
B
C
A = ON - Change setting
B = OFF
C = ON - Element blocking
≥ 1
≥ 1
A
B
C
A = ON - Change setting
A
B
C
C = ON - Element blocking
A
B
C
B = OFF
CB State CB OPEN CB CLOSED CB OPEN
t
0.1 s
HIGH THRESHOLD/
BLOCK
LOW THRESHOLD/
UNBLOCK
HIGH THRESHOLD/
BLOCK
CB-State