18
18
NC20 - Manual - 01 - 2015
TECHNICAL DATA
I
N>AL
Element
I
NCLP>AL
Activation time (
t
NCL>PAL
)
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
46N Alarm threshold defi nite time (
I
N>ALdef
)
0.01...1.00
I
Nn
(step 0.01
I
Nn
)
I
N>ALdef
within CLP (
I
NCLP>ALdef
) 0.01...1.00
I
Nn
(step 0.01
I
Nn
)
I
N>ALdef
Operating time (
t
N>ALdef
)
0.03...500
s
0.03...9.99 s (step 0.01 s)
10.0...99.9 s (step 0.1 s)
100...500 s (step 1 s)
I
N>
Element
I
N>
Curve type (
I
N>
Curve)
DEFINITE, IEC/BS A, B, C,
ANSI/IEEE MI, VI, EI
I
NCLP
>
Activation time (
t
NCLP>
)
0.00...100.0 s (step 0.01 s)
Defi nite time
46N First threshold defi nite time (
I
N>def
)
0.01...2.00
I
Nn
(step 0.01
I
Nn
)
I
N>def
within CLP (
I
NCLP>def
)
0.01...2.00
I
Nn
(step 0.01
I
Nn
)
I
N>def
Operating time (
t
N
>
def
)
0.03...50.0
s
0.03...9.99 s (step 0.01 s)
10.0...50.0 s (step 0.1 s)
Inverse time
[1]
46N First threshold inverse time (
I
N>inv
)
0.01...1.00
I
Nn
(step 0.01
I
Nn
)
I
N>inv
within CLP (
I
NCLP>inv
)
0.01...1.00
I
Nn
(step 0.01
I
Nn
)
I
N>inv
Operating time (
t
N>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
N>>
Element
I
NCLP
>>
Activation time (
t
NCLP>>
) 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
46N Second threshold defi nite time (
I
N>>def
)
0.01...2.00
I
Nn
(step 0.01
I
Nn
)
I
N>>def
within CLP (
I
NCLP>>def
)
0.01...2.00
I
Nn
(step 0.01
I
Nn
)
I
N>>def
Operating time (
t
N>>def
)
0.03...50.0
s
Pickup
time
≤
0.04
s
Dropout
ratio
0.95...0.98
Dropout time
≤ 0.05 s
Overshoot
time
0.04
s
Pickup accuracy
±
1% with 0.1
I
Nn
, ±
1% with 1
I
Nn
Operate time accuracy
5% or ± 10 ms
Thermal image - 49
[2]
Common confi guration:
Initial thermal image
Δθ
IN
(
Dth
IN
) 0.0...1.0
Δθ
B
(step 0.1
Δθ
B
)
Reduction factor at inrush (
K
INR
) 1.0...3.0
(step
0.1)
Thermal time constant
τ
(
T
)
1...200 min (step 1 min)
Dth
CLP
activation time
(
t
dthCLP
)
0.00...100.0
s
0.00...9.99 s (step 0.01 s)
10.0...100.0 s (step 0.1 s)
DthAL1 Element
49 First alarm threshold
(
Dth
AL1
) 0.3...1.0
Δθ
B
(step 0.1
Δθ
B
)
DthAL2 Element
49 Second alarm threshold
(
Dth
AL2
)
0.5...1.2
Δθ
B
(step 0.1
Δθ
B
)
Dth> Element
49 Trip threshold (
Dth
>)
1.100...1.300
Δθ
B
(step 0.001
Δθ
B
)
Pickup accuracy
±
1% with 0.1
I
n
, ±
1% with 1
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
N>inv
/ [(I
NC
/I
N>inv
)
0.02
- 1]
Very Inverse Time (IEC 255-3/BS142 type B or VIT):
t = 13.5 · t
N>inv
/ [(I
NC
/I
N>inv
) - 1]
Extremely Inverse Time (IEC 255-3/BS142 type C or EIT):
t = 80 · t
N>inv
/ [(I
NC
/I
N>inv
)
2
- 1]
Moderately Inverse (ANSI/IEEE type MI):
t = t
N>inv
· {0.01 / [(I
NC
/I
N>inv
)
0.02
- 1] + 0.023}
Very Inverse (ANSI/IEEE type VI):
t = t
N>inv
· {3.922 / [(I
NC
/I
N>inv
)
2
- 1] + 0.098}
Extremely Inverse (ANSI/IEEE type EI):
t = t
N>inv
· {5.64 / [(I
NC
/I
N>inv
)
2
- 1] + 0.024}
I
NC
:
Neutral compensated current (see note 2)
t
:
operate time
I
N>inv
:
threshold setting
t
N>inv
:
operate time setting
Asymptotic reference value:
1.1
I
N>inv
Minimum operate time:
0.1
s
Equation is valid for 1.1 ≤ I
NC
/I
N>inv
≤ 20, with I
N>inv
pickup ≥
0.15
I
Nn
, the upper limit is
3
I
Nn
Note 2 The equivalent thermal current is based on the greater RMS phase current.
I
th
=
I
LMAX
= max(
I
L1RMS
,
I
L2RMS
,
I
L3RMS
);
the computed RMS
value takes into account the contribution of fundamental and harmonic up to eleventh order.
