Thytronic NA20, Manual, Page: 16 / 208

TECHNICAL DATA
16 NA20 - Manual - 04 - 2022
3.6 GENERAL SETTINGS
Relay nominal frequency ( f
n
) 50, 60 Hz
Relay phase nominal current ( I
n
) 1 A or 5 A
[1]
Phase CT primary nominal current ( I
np
) 1 A...10 kA
1...499 A (step 1 A)
500...4990 A (step 10 A)
5000...10000 A (step 100 A)
Relay residual nominal current ( I
En
) 1 A or 5 A
[1]
Residual CT primary nominal current ( I
Enp
) 1 A...10 kA
1...499 A (step 1 A)
500...4990 A (step 10 A)
5000...10000 A (step 100 A)
3.7 PROTECTIVE FUNCTIONS
‡ Base current - IB
[2]
Base current ( I
B
) 0.10...2.50 I
n
(step 0.01 I
n
)
‡ Thermal protection with Pt100 probes - 26
[3]
ThAL1...8 Alarm:
Alarm threshold 26 PT1...PT8 ( Th
AL1...8
) 0...200 °C
Operating time ThAL1...8 (t Th
AL1...8
) 0....100 s
Th>1...8 Trip:
Trip threshold 26 PT1...PT8 ( Th>
1...8
) 0...200 °C
Operating time ThAL1...8 (t Th>
1...8
) 0....100 s
‡ Undercurrent - 37
37 Operating logic ( Logic 37) AND/OR
Definite time
37 First threshold definite time ( I <
def
) 0.10...1.00 I
n
(step 0.01 I
n
)
I <
def
Operating time ( t <
def
) 0.04...200 s
0.04...9.99 s (step 0.01 s)
10.0...99.9 s (step 0.1 s)
100...200 s (step 1 s)
Pickup time ≤ 0.03 s
Dropout ratio 1.03...1.05
Dropout time ≤ 0.05 s
Overshoot time 0.03 s
Pickup accuracy ± 0.5% with 0.1 I
n
, ± 0.2% with 1 I
n
Operate time accuracy 5% or ± 10 ms
‡ Negative sequence overcurrent - 46
I
2
> Element
I
2
> Curve type ( I
2
>
Curve
) DEFINITE
IEC/BS A, B, C
ANSI/IEEE MI, VI, EI
I
2
t, EM
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 First threshold definite time ( I
2
>
def
) 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
>
def
within CLP ( I
2CLP>def
) 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
>
def
Operating time ( t
2
>
def
) 0.03...200 s
0.03...9.99 s (step 0.01 s)
10.0...99.9 s (step 0.1 s)
100...200 s (step 1 s)
Note 1 The nominal current settings doesn’t concern the protection elements; they must agree with hardware setting (dip-switch 1 A or 5 A) .
Note 2 The basic current I
B
represents the nominal current of the line or transformer, referred to the nominal current of the CT’s for thermal image
protection. If the secondary rated current of the line CT’s equals the rated current of the NA20 relay, as usually happens, the I
B
value is the ratio
between the rated current of the protected element and the primary rated current of the CT’s
Note 3 The 26 element is available when the MPT module is connect on Thybus and enabled