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DMC3S - Manual - 08 - 2021
The first threshold IE> can be inhibited by the start of at least one of the two thresholds IE>>, IE>>>
with Deactivation IE> by start IE>>, Deactivation IE> by start IE>>> (
IE>disbyIE>>, IE>disb-
yIE>>>
) in the menu
Set \ Protections \ Residual overcurrent - 50N/51N \
Threshold IE>>, Thresh-
old IE>>>\ Parameters
.
In the same way, the second threshold IE>> can be inhibited by the start of the third threshold IE>>>
with Deactivation IE>> by start IE>>> (
IE>>disbyIE>>>
) in the menu
Set \ Protections \ Resid-
ual overcurrent - 50N/51N \
Threshold IE>>>\ Parameters.
.
A constant reset time can be set for each of the thresholds (
t
E>
RES
,
t
E>>
RES
,
t
E>>>
RES
).
Shrink time
For each of the thresholds programmed with definite time characteristic, you can select contracted
time by setting to
ON
the parameter
EnTcIE>def
,
EnTcIE>>def
,
EnTcIE>>>def
and
regulating the contracted time (
tcIE>def,
tcIE>>def,
tcIE>>>def
) and operating time (
tat-
cIE>def,
tatcIE>>def,
tatcIE>>>def
).
Once the breaker closes, during the operating time (e.g.:
tatcIE>def
), the value of the trip time
(e.g.:
tE>def
) is replaced by the contracted time (e.g.:
tcIE>def
); when the operating time ex-
pires the trip time is reset (e.g.:
tE>def
).
The parameters are available in the menu
Set \ Protections \ Residual overcurrent - 50N/51N \
Threshold IE>
(
Threshold IE>>, Threshold IE>>>) \ Definite time
.
Second harmonic restraint
For each of the three thresholds (
I
E
>,
I
E
>>,
I
E
>>>) you can set a second harmonic restraint block
by setting to
ON
the parameter
IE>2ndh-REST, IE>>2ndh-REST, IE>>>2ndh-REST
.
The parameters are available in the menu
Set \ Configuration parameters A(or B) \ Residual overcur-
rent - 50N/51N \
Threshold IE>
(
Threshold IE>>
,
Threshold IE>>>) \ Parameters.
Fun_50N-51NS1.ai
t
>RES
T
0
RESET
t
E>
0
T
≥
1
t
E>inv
t
E>RES
Start IE>
Trip IE>
Start
I
2ndh>
ON
≡
Inhibit
(from IE>> and/or IE>>> residual overcurrent element)
ON
≡
Enable IE> residual overcurrent element
IE> inhibition
Block1, Block2
&
&
2nd harmonic restraint enable (ON
≡
Enable)
IE>2ndh-REST
TR
IP
PI
NG M
AT
RI
X
(LE
D+R
EL
AY
S)
I
E
> Curve
0
T
IE> Enable
I
E
>TR-K
I
E
>TR-L
I
E
>ST-L
I
E
>ST-K
I
E
≥
1
&
State
I
E
>
inv
I
E
≥
I
E
>
def
I
E
≥
I
E
>
inv
I
E
>
def
&
State
&
EnTcIE>def
t
E>def
t
CIE>def
t
atcIE
>
def
t
atcIE
>
def
CB control
0 =
t
E>def
1 =
t
CIE>def
“0”
“1”
CB control
tatcIE>def
tcIE>def
tE>def
tE>def
BREAKER OPEN
Breaker state
Shrink time enable
Threshold timer
t
BREAKER CLOSED
OFF
Shrink time trip
ON
Functional diagram of the first threshold (IE>) of the residual overcurrent function 50N/51N
