TECHNICAL DATA
17
NA011 - Manual - 05 - 2022
Residual overcurrent - 50N/51N
IE> Element
I
E
> Curve type (
I
E
>
Curve
) DEFINITE,
IEC/BS A, B, C,
ANSI/IEEE MI, VI, EI, I2T
CLP Activation time (
t
ECLP>
)
0.00...100.0 s
0.00...9.99 s (step 0.01 s)
10.0...100.0 s (step 0.1 s)
I
E
> Reset time delay (
t
E
>
RES
)
0.00...100.0 s
0.00...9.99 s (step 0.01 s)
10.0...100.0 s (step 0.1 s)
Definite time
50N/51N First threshold definite time (
I
E
>
def
)
0.005...5.00
I
En
0.005...0.999
I
En
(step 0.001
I
En
)
1.00...5.00
I
En
(step 0.01
I
En
)
I
E
>
def
within CLP (
I
ECLP>def
)
0.005...5.00
I
En
0.005...0.999
I
En
(step 0.001
I
En
)
1.00...5.00
I
En
(step 0.01
I
En
)
I
E
>
def
Operating time (
t
E
>
def
)
0.03...10.00 s (step 0.01 s)
Inverse time
[1]
50N/51N First threshold inverse time (
I
E
>
inv
)
0.005...2.00
I
En
0.005...0.999
I
En
(step 0.001
I
En
)
1.00...2.00
I
En
(step 0.01
I
En
)
I
E
>
inv
Operating time (
t
E
>
inv
)
0.02...60.0
s
0.02...9.99 s (step 0.01 s)
10.0...60.0 s (step 0.1 s)
IE>> Element
I
E
>> Curve type (
I
E
>>
Curve
)
DEFINITE,
IEC/BS A, B, C,
ANSI/IEEE MI, VI, EI, I2T
CLP Activation time (
t
ECLP>>
)
0.00...100.0 s
0.00...9.99 s (step 0.01 s)
10.0...100.0 s (step 0.1 s)
I
E
>> Reset time delay (
t
E
>>
RES
)
0.00...100.0 s
0.00...9.99 s (step 0.01 s)
10.0...100.0 s (step 0.1 s)
Definite time
50N/51N Second threshold definite time (
I
E
>>
def
) 0.005...5.00
I
En
0.005...0.999
I
En
(step 0.001
I
En
)
1.00...5.00
I
En
(step 0.01
I
En
)
I
E
>>
def
within CLP (
I
ECLP>>def
)
0.005...5.00
I
En
0.005...0.999
I
En
(step 0.001
I
En
)
1.00...5.00
I
En
(step 0.01
I
En
)
I
E
>>
def
Operating time (
t
E
>>
def
)
0.03...10.00 s (step 0.01 s)
Note 1
Standard Inverse Time (IEC 255-3/BS142 type A or SIT):
t = 0.14 · t
E
>
inv
/ [(I
E
/ I
E
>
inv
)
0.02
- 1]
Very Inverse Time (IEC 255-3/BS142 type B or VIT):
t = 13.5 ·
t
E
>
inv
/ [(I
E
/I
E
>
inv
) - 1]
Extremely Inverse Time (IEC 255-3/BS142 type C or EIT):
t = 80 ·
t
E
>
inv
/ [(I
E
/I
E
>
inv
)
2
- 1]
Moderately Inverse (ANSI/IEEE type MI):
t =
t
E
>
inv
· {0.01 / [(I
E
/I
E
>
inv
)
0.02
- 1] + 0.023}
Very Inverse (ANSI/IEEE type VI):
t =
t
E
>
inv
· {3.922 / [(I
E
/I
E
>
inv
)
2
- 1] + 0.098}
Extremely Inverse (ANSI/IEEE type EI):
t =
t
E
>
inv
· {5.64 / [(I
E
/I
E
>
inv
)
2
- 1] + 0.024}
I-squared-t (I
2
t = K):
t = 16 · t
E
>
inv
/ (I/I
E
>
inv
)
2
where:
I
E
:
residual current input
t
:
operate time
I
E
>
inv
:
pickup value
t
E
>
inv
:
operate time setting
Asymptotic reference value:
1.1
I
E
>
Minimum operate time:
0.1
s
Equation is valid for 1.1 ≤ I
E
/ I
E
>
inv
≤ 20