Thytronic NA011 - Page 18

TECHNICAL DATA
18
NA011 - Manual - 05 - 2022
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)
Pickup time ≤ 0.03 s
Dropout ratio 0.95...0.98
Dropout time ≤ 0.04 s
Overshoot time 0.03 s
Pickup accuracy ± 4% ± 1% I
En
Operate time accuracy 5% or ± 10 ms
 Breaker Failure
BF Time delay (t
BF)
0.10...10.00 s
0.10...0.99 s (step 0.01 s)
1.00...10.00 s (step 0.05 s)
1.0...0.99 s (step 0.01 s)
Operate time accuracy 5% or ± 10 ms
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