Thytronic DMC3S - Page 53

53
DMC3S - Manual - 08 - 2021
Second harmonic restraint
Asecond harmonic restraint block can be set by setting to ON the parameter IEeme>2ndh-
REST.
The related parameters are available in the menu Set \ Protections \ Residual emergency overcur-
rent - 51N(Eeme) \ Threshold IEeme>\ Parameters.
I
SQL
t
SQL >RES
T0
RESET
t
SQL >
0T
≥1
≥1
t
SQL >inv
t
SQL >RES
Start I
SQL
>
Trip I
SQL
>
Start I
2ndh>
ON≡Enable I> overcurrent element
Block1, Block2
&
&
2nd harmonic restraint enable (ON≡Enable)
I>2ndh-REST
TRIPPING MATRIX (LED+RELAYS)
I
SQL
> Curve
0T
ISQL> Enable
I>TR-K
I>TR-L
I>ST-L
I>ST-K
&
State
I
SQL
>
inv
I
SQL
≥ I
SQL
>
def
I
SQL
≥ I
SQL
>
inv
I
SQL
>
def
&
State
&
EnTcI
SQL
>def
“0”
t
SQL >def
t
CI SQL >def
t
atcI
>
def
t
atcI
SQL
>
def
CB control
0 = t
SQL >def
1 = t
CI SQL >def
“1”
CB control
tatcISQL>def
tcISQL>deftSQL>def tSQL>def
BREAKER OPEN
Breaker state
Shrink time enable
Threshold timer
t
BREAKER CLOSED
OFF
Shrink time trip
ON
Functional diagram of the threshold of the neutral current unbalance function 51(SQL)