Thytronic NA20, Manual, Page: 17 / 208

TECHNICAL DATA
17 NA20 - Manual - 04 - 2022
Inverse time
[1]
46 First threshold inverse time ( I
2
>
inv
) 0.100...10.00 I
n
0.100...0.999 I
n
(step 0.001 I
n
)
1.00...5.00 I
n
(step 0.01 I
n
)
I
2
>
inv
within CLP ( I
2CLP>inv
) 0.100...10.00 I
n
0.100...0.999 I
n
(step 0.001 I
n
)
1.00...10.00 I
n
(step 0.01 I
n
)
I
2
>
inv
Operating time ( t
2
>
inv
) 0.02...60.0 s
0.02...9.99 s (step 0.01 s)
10.0...60.0 s (step 0.1 s)
I
2
>> Element
I
2CLP
>> Activation time ( t
2CLP>>
) 0.00...100.0 s
0.00...9.99 s (step 0.01 s)
10.0...100.0 s (step 0.1 s)
I
2
>> Reset time delay ( t
2
>>
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
46 Second threshold definite time ( I
2
>>
def
) 0.100...40.0 I
n
0.100...0.999 I
n
(step 0.001 I
n
)
1.00...40.00 I
n
(step 0.01 I
n
)
I
2
>>
def
within CLP ( I
2CLP>>def
) 0.100...40.0 I
n
0.100...0.999 I
n
(step 0.001 I
n
)
1.00...40.00 I
n
(step 0.01 I
n
)
I
2
>>
def
Operating time ( t
2
>>
def
) 0.03...10.00 s (step 0.01 s)
Pickup time
≤
0.03 s
Dropout ratio 0.95...0.98
Dropout time
≤
0.05 s
Overshoot time 0.03 s
Pickup accuracy 1% with I
2
≥ 0.5 I
n
Operate time accuracy 5% or ± 10 ms
‡ Negative sequence / positive sequence current ratio - I
2
/ I
1
I
21
> Element
I
21CLP
> Activation time ( t
21CLP>
) 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
I
2
/ I
1
> First threshold definite time ( I
21
>
def
) 0.10...1.00 I
n
(step 0.01 I
n
)
I
2
/ I
1
> within CLP (( I
21CLP
>
def
0.10...1.00 I
n
(step 0.01 I
n
)
I
21
>
def
Operating time ( t
21
>
def
) 0.04...15000 s
0.04...9.99 s (step 0.01 s)
1...15000 s (step 1 s)
Pickup time
≤
0.03 s
Dropout ratio 0.95...0.98
Dropout time
≤
0.05 s
Overshoot time 0.03 s
Pickup accuracy 1% with I
1
and I
2
≥ 0.5 I
n
Operate time accuracy 5% or ± 10 ms
Note 1 Standard Inverse Time (IEC 255-3/BS142 type A or SIT): t = 0.14 · t
2
>
inv
/ [(I
2
/I
2
>
inv
)
0.02
- 1]
Very Inverse Time (IEC 255-3/BS142 type B or VIT): t = 13.5 · t
2
>
inv
/ [(I
2
/I
2
>
inv
) - 1]
Extremely Inverse Time (IEC 255-3/BS142 type C or EIT): t = 80 · t
2
>
inv
/ [(I
2
/I
2
>
inv
)
2
- 1]
Moderately Inverse (ANSI/IEEE type MI): t = t
2
>
inv
· {0.01 / [(I
2
/I
2
>
inv
)
0.02
- 1] + 0.023}
Very Inverse (ANSI/IEEE type VI): t = t
2
>
inv
· {3.922 / [(I
2
/I
2
>
inv
)
2
- 1] + 0.098}
Extremely Inverse (ANSI/IEEE type EI): t = t
2
>
inv
· {5.64 / [(I
2
/I
2
>
inv
)
2
- 1] + 0.024}
I-squared-t (I
2
t = K): t = 16 · t
2
>
inv
/ (I
2
/I
2
>
inv
)
2
Electromechanical (EM): t = 0.28 · t
2
>
inv
/ [-0.236 · (I
2
/I
2
>
inv
)
-1
+ 0.339]
t : operate time
I
2
>
inv
: pickup value
t
2
>
inv
: operate time setting
Asymptotic reference value: 1.1 I
2
>
nv
Minimum operate time: 0.1 s
Equation is valid for 1.1 ≤ I
2
/I
2
>
inv
≤ 20
With I
2
>
inv
pickup ≥ 2.5 I
n
, the upper limit is 50 I
n