Thytronic NA20, Manual, Page: 85 / 208

FUNCTION CHARACTERISTICS
85 NA20 - Manual - 04 - 2022
Fun_50N-51NS2.ai
t
E>>RES
T 0
RESET
t
E>>
0 T
≥ 1
t
E>>def
t
E>>RES
Start IE>>
Trip IE> >
CB-State
Start I
2ndh>
IE > > inhibition
Block1, Block2
&
IE> > TR-K
IE> > TR-L
IE> > ST-L
IE> > ST-K
T 0
t
ECLP>>
&
2nd harmonic restraint enable (ON
≡
Enable)
IE>>2ndh-REST
IECLP>>Mode
t
ECLP>>
BF Enable (ON ≡ Enable)
IE>>BF
towards BF logic
IE>> BF
&
Trip IE>>
TR
IP
PIN
G
M
AT
RIX
(
LE
D+R
EL
AY
S)
A
B
C
Output
t
ECLP>>
IE >> Enable
IE>> overcurrent element (50/51) Block diagram
t
ECLP>>
CB State CB OPEN CB CLOSED CB OPEN
Output t
ECLP
>
>
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 IE>>
Start IE>>
IE> inhibition
IE> disbylE>>
≥ 1
CLP IE>>
ON ≡ Inhibit
(from IE>>> residual overcurrent element)
ON ≡ Enable IE>> residual overcurrent element
I
E>>def
A =“1” A =“0 or OFF”
I
E
(Pickup within CLP)
(Pickup outside CLP)
I
ECLP>>def
I
E
≥ I
ECLP
>>def
&
State
I
E
≥ I
E
>>
def
Residual overcurrent (50N/51N) - Second element logic diagram (IE>>)