Thytronic NA11, Manual

Page: 16 / 190

16
16 NA11 - Manual - 02 - 2009 TECHNICAL DATA
3.6 GENERAL SETTINGS
Relay nominal frequency f
n
50, 60 Hz
Standard CTs:
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)
LPCT - Low Power Current Transformers:
Relay phase nominal current ( I
np
) 50...1250 A
Relay residual nominal current I
En
1 A o 5 A
[3][2]
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 ELEMENTS
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
Phase overcurrent - 50/51 - settings for 1/5 A standard CTs version
I> Element
I > Curve type ( I>
Curve
) DEFINITE
IEC/BS A, B, C
ANSI/IEEE MI, VI, EI
RECTIFIER, I
2
t or EM
I
CLP
> Activation time ( t
CLP>
) 0.00...100.0 s
0.00...9.99 s (step 0.01 s)
10.0...100.0 s (step 0.1 s)
I > Reset time delay ( t >
RES
) 0.00...100.0 s
0.00...9.99 s (step 0.01 s)
10.0...100.0 s (step 0.1 s)
Defi nite time
50/51 First threshold defi nite time ( I >
def
) 0.100...5.00 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 >
def
within CLP ( I
CLP>def
) 0.100...5.00 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 >
def
Operating time ( t >
def
) 0.04...200.00 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)
Inverse time
[4]
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 1 - 5 A selection is meaningful for standard CTs versions; the computed residual current is employed for NA11 protection relays equipped with
LPCT sensor inputs
Note 3 The 26 element is available when the MPT module is connect on Thybus and enabled
Note 4
Standard Inverse Time (IEC 255-3/BS142 type A or SIT): t = 0.14 · t>
inv
/ [(I/I>
inv
)
0.02
- 1]
Very Inverse Time (IEC 255-3/BS142 type B or VIT): t = 13.5 · t>
inv
/ [(I/I>
inv
) - 1]
Extremely Inverse Time (IEC 255-3/BS142 type C or EIT): t = 80 · t>
inv
/ [(I/I>
inv
)
2
- 1]
Moderately Inverse (ANSI/IEEE type MI): t = t>
inv
· {0.01 / [(I/I>
inv
)
0.02
- 1] + 0.023}
Very Inverse (ANSI/IEEE type VI): t = t>
inv
· {3.922 / [(I/I>
inv
)
2
- 1] + 0.098}
Extremely Inverse (ANSI/IEEE type EI): t = t>
inv
· {5.64 / [(I/I>
inv
)
2
- 1] + 0.024}
I-squared-t (I
2
t = K): t = 16 · t>
inv
/ (I/I>
inv
)
2
Electromechanical (EM): t = 0.28 · t>
inv
/ [-0.236 · (I/I>
inv
)
-1
+ 0.339]
RECTIFIER (RI): t = 2351 · t>
inv
/ [(I/I>
inv
)
5.6
- 1]
t : operate time
I>
inv
: pickup value
t>
inv
: operate time setting
Asymptotic reference value: 1.1 I >
inv
Minimum operate time: 0.1 s
Equation is valid for 1.1 ≤ I/I>
inv
≤ 20
With I>
inv
pickup ≥ 2.5 I
n
, the upper limit is 50 I
n
‡
‡