INTRODUCTION
6
NC020 - Manual - 05 - 2022
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Product identification
Each device is equipped with:
• Identification label installed on the front side with following informations: code number, phase and
residual nominal currents, auxiliary voltage range and CE mark:
• Test label with following informations: data, serial number and test operator signature.
—
Environment
The NC020 device must be employed according to the environment conditions shown (see technical
data).
In case of different environment conditions, appropriate provisions must be provided (conditioning
system, humidity control, etc...).
If contaminants are present (dust, corrosive substances, etc...), filters must be provided.
—
Graphical conventions
The CEI/IEC and ANSI symbols is employed where possible:
e.g.: 51 = ANSI code concerning the overcurrent element.
Following text formats are used:
The ThyVisor
[1]
menu:
Phase overcurrent -50/51
The parameter description (measures, thresholds, operate time,...) and related value:
First threshold 50/51 definite time
I>def
The display messages (MMI) are shown as:
NC020
Notes are highlighted with cursive letters inside colored bar
Note: Useful description note
—
Glossary/definitions
I
n
Relay phase rated current
I
np
Phase CT primary rated current
I
Nn
Relay neutral rated current
I
Nnp
Phase CT neutral rated current
I
NC
Compensation neutral current
I
EC
Calculated residual rated current
V
1
,
V
2
,
V
3
Calculated peak voltages
46N
Neutral unbalance overcurrent ANSI code
50/51
Phase overcurrent ANSI code
50/51 RMS
Phase overcurrent ANSI code
50N/51N
Residual overcurrent ANSI code
59H
Peak overvoltage ANSI code
TD
Discharge timer
DFR
Digital Fault Recorder (Oscillography)
SER
Sequential Event Recorder
SFR
Sequential Fault Recorder
ANSI
American National Standard Institute
IEEE
Institute of Electrical and Electronics Engineers
IEC
International Electrotechnical Commission
CENELEC
Comité Européen de Normalisation Electrotechnique
52 o CB (Circuit Breaker)
Circuit Breaker
52a
Auxiliary contact in the breaker that is in the same position as the
breaker. It can be assigned to a binary input to locate the CB posi-
tion (Breaker failure and/or CB diagnostic functions). (52a open = CB
open)
Note 1 The graphic interface and the operation of the ThyVisor software are described in the relative chapters
NC020#xM000
I
n
1A
50-51
46N-50N
59
CB OPEN
TD
5A
U
AUX
24-230 Vac/dc
I
Nn
1A
5A
1
2
3
4
5