GENERAL
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NC020 - Manual - 05 - 2022
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Main features
• Metallic case.
• Backlight LCD 2x16 Display.
• Eight LEDs that may be joined with matrix criteria to many and various functions.
• RESET key to clear LED indications and latched output relays.
• Free settable three binary inputs.
• Independently settable for start, trip, self-test and control four output relay (K1...K4); each output
relay may be set with normally energized or normally de-energized operating mode and manual or
automatic reset (latched/no-latched).
• Rear RS485 port, with ModBus protocol.
• RS232 front serial port (local communication for ThyVisor).
• Real time clock with super capacitor backup.
The most significant constructive features are:
• Galvanically insulated input and output circuits (communication and binary circuits included).
• Fast sampling rate for inputs.
• Optimum filtering of input signals through combined use of analog and digital filters.
• Traditional electromechanical-type final output contacts with continuous monitoring of control coil
continuity.
• Auxiliary supply comprising a switching-type voltage stabilizing circuit having a very wide working
range and a very small power dissipation
• Nominal frequency: 50 or 60 Hz.
The most significant operating features are:
• Programming of operating modes and parameters by means of the front keys and alphanumeric
display, with a programming procedure based on carrying out guided selections and on explicit and
immediate signalling of the operations being performed, so that such procedure can be carried out
without coding tables or mnemonic informations.
• The feature modification operations do not interrupt the normal functions of the relay.
• Impossibility of programming unacceptable parameter values, thanks to the automatic limitation of
top and bottom scale values for the relative setting ranges.
• Currents are sampled 48 times per period and measured in the effective value (RMS) of the funda-
mental component using the DFT (Discrete Fourier Transform) algorithm and digital filters.
• The fault recorder (SFR) runs continuously capturing in circular mode the last twenty events upon
trigger of binary input/output and/or element pickup (start-trip).
• The event recorder (SER) runs continuously capturing in circular mode the last fifty events upon
trigger of binary input/output.
• Digital fault recorder (DFR) in COMTRADE format (oscillography).