TECHNICAL DATA
15
NC020 - Manual - 05 - 2022
3.4 MMI
Display
16x2 LCD backlight module
LEDs
• ON/fail
1 (green)
• Start
1 (yellow)
• Trip
1 (red)
• Trip I>, I>>, I>>> RMS and fundamental (red)
1 (red)
• Trip 46N, 50N
1 (red)
• Trip 59H
1 (red)
• 52b - Circuit Breaker position
1 (red)
• TD - state
1 (red)
Keyboard
8
keys
[1]
3.5
COMMUNICATION INTERFACES
—
Local port
RS232
• Connection
RJ10
• Baud rate
19200 bps
• Parity
None
• Protocol
ModBus®RTU
—
Remote port
RS485
• Connection
screw terminals
• Baud rate
1200...57600 bps
• Parity
None
• Protocol
ModBus®RTU
3.6
GENERAL SETTINGS
Relay rated frequency
f
n
50, 60 Hz
Phase CT primary rated current
I
np
[2]
1 A...5000 A
1...99 A (step 1 A)
100...5000 A (step 5 A)
Neutral CT primary rated current
I
Nnp
[3]
1 A...5000 A
1...99 A (step 1 A)
100...5000 A (step 5 A)
3.7
PROTECTIVE ELEMENTS
—
Discharge time - TD
tD Discharge time (
t
D
)
6...6000 s (step1 s)
—
Undercurrent - 37
[4]
I< Element
Definite time
37 First threshold definite time (
I<
def
)
0.1
I
n
I<
def
Operating time (
t
I
<
def
)
0.100
s
I<< Element
Definite time
37 Second threshold definite time (
I<<
def
) 0.05...1.00
I
n
(step 0.01
I
n
)
I<<
def
Operating time (
t
I
<<
def
)
0.03...600
s
0.03...9.99 s (step 0.01 s)
10.0...99.9 s (step 0.1 s)
100...600 s (step 1 s)
—
Neutral unbalance overcurrent - 46N
[5]
Compensation:
[6]
Compensation current (
I
NC MOD calib
)
0.01...0.50
I
Nn
(step 0.01
I
Nn
)
Compensation angle (
I
NC PHI calib
) 0...359°
(step 1°)
Nota 1 The “
O
” and “
I
” keys are enabled for CB opening and closing
Note 2 The rated current settings doesn’t concern the 50/51 protection elements; they must agree with nominal primary current for CT inputs for a
correct reading of the phase current primary values (Reading Direct).
Note 3 The nominal current settings doesn’t concern the 46N protection element; it must agree with nominal primary current of the CT inputs for a
correct reading of the unbalance neutral current primary values (Reading Direct).
Note 4 The 37 protection is based on RMS value measurement of three phase currents (the computed RMS value takes into account the contribution
of fundamental and harmonic up to twenty-third order). The first element is an internal element servicing the Timer Discharge (TD) function
Note 5 The 46N protection is based on
I
NC
neutral compensated current
I
NC
= I
N
- I
C
(I
N
= RMS value of fundamental component for neutral current,
I
C
= compensation setting for neutral current).
Note 6 Setting of the compensation parameters are available inside the Set \ IN Compensation menu.
