Non-directional time delay over-current protection with definite time;
Possibility for acceleration before or after Autoreclosing;
Possibility for acceleration in case of remote or manual circuit breaker (CB) closing.

Non-directional instantaneous (or with time delay) over-current protection;
Three possibilities for the operational principle – non selective protection for cable line, non-selective protection, overhead line (blocked when autoreclosing is OFF) or selective protection;
Possibility for acceleration before or after autoreclosing;
Possibility for acceleration in case of remote or manual CB closing;
Possibilities for blocking of the function from an external signal received by dedicated binary inputs.

Non-directional inverse time delay overcurrent protection
Selectable time delay characteristic according to IEC and ANSI standards:
According IEC: Inverse time, Very Inverse, Extremely Inverse, Long Inverse, RI Inverse
According ANSI: Long Inverse, Moderately Inverse, Very Inverse, Extremely Inverse, Isquared T

Non-directional ground-fault protection with definite time delay;
Up to 3 stages and possibility for switching ON or OFF for each stage separately;
Possibility for acceleration at autoreclosing for each stage separately;
Possibility for acceleration in case of remote or manual circuit breaker (CB) clos-ing for each stage separately.

Non-directional protection;
Selectable time delay characteristic according to IEC and ANSI standards:
According IEC: Inverse time, Very Inverse, Extremely Inverse, Long Inverse, RI Inverse
According ANSI: Long Inverse, Moderately Inverse, Very Inverse, Extremely Inverse, Isquared T

Evaluation of negative sequence component of the currents – ANSI 46;
In line protection, the negative-sequence protection permits detection on the high side of high-resistance phase-to-phase faults and phase-to-earth faults that are on the low side of a transformer. This provides backup protection for high-resistance faults beyond the transformer. To detect the unbalanced load, the ratio negative-sequence current/rated (nominal) current is evaluated;
A measured current element for the negative sequence current - I₂;
Timer activated at current measuring element pick-ups;
Possibilities for blocking of the NSOC from an external signal received by dedicated binary input.

Uses a thermal model of the line based on its heating and cooling time constants and an exponential law of alteration;
Monitors the temperature state through the relative temperature which is connected with the squared current of the line;
In case of overload the protection picks-up with a delay which depends on the degree of overload;
The protection has two stages providing trip and pre-trip alarm outputs;
Possibilities for blocking of the TOL from an external signal received by dedicated binary input.

Protect the feeder in case of current unbalance;
Monitors the maximum difference between the effective values of the three phase currents;
Switches off automatically if the maximum phase current exceeds the threshold setting;
Except for the unbalanced voltage supply, the protection picks up at the interterm faults and at double-phase short circuits near to the neutral.

Autoreclosing function acc. ANSI 79AR;

Up to 6 shots;
The device is equipped with an operation counter for counting the rapid and delayed autoreclosings (AR) - counting the one-shot AR, two-shots AR, three shots AR and four-, five-, six-shots AR. Also two special counters are implemented into the device - for counting the successfully done and unsuccessfully done AR.

Starting condition:
At the circuit breaker and control switch position discrepancy• at the circuit breaker and control switch position discrepancy
At tripping command: from internal protections; from external protections - by binary inputs; from internal or external protections.

Visualization of the circuit breaker’s phase life time;
Signalization of CB run out of resource;
Possibility for describing of the CB life time curves;
Possibility for editing the CB’s life time value for each phase.

The RFI 401 device has 4 selectable setting groups including all protection and automation functions. Commutation between the separate groups can be achieved locally, remotely or via dedicated binary inputs.

The event recorder memory buffer is designed for up to 2000 records.
Each of the records consists of information about the event type, the real time of its appearance (year, month, day, hour, minute, second, second/1000) and in certain cases – some numerical data characterizing the process recorded.
The information recorded is stored in non-volatile memory and can be shown on the device’s display and/or memorized on the PC running the MMI program.
In the unit’s memory the stored event can be found and displayed using the following attributes:
Last stored event
The events stored during the last hour
The events stored during last 24 hours
The events stored during the last month (up to the same moment in the previous month)
The records stored during the chosen day

The device can be connected to Work Station in SCADA-system by means of local network. The network is based on RS485 or fiber optic – the respective interface connector is used. The communication protocol is IEC 60870-5-103 / IEC 61850. The device’s data acquisition and remote control functions are performed by means of work station – measuring, signaling, remote control (opening or closing command to the circuit breaker, disconnecttors, earthing switch).
Additionally by work station facilities the device can be configured its settings parameters, can be read and corrected and all stored into unit’s memory data can be archived. Also all data stored by means of “Disturbance recorder” and “Event recorder” functions can be transferred and archived into WS for farther analysis.

Device’s HMI interface is situated on the front panel. It consists of:
LCD display – 2 rows, 16 characteristics each. The display has back light illumination
Indication zone of 9 LED’s (green LED “READY” and 8 red colored S1 – S8 which are free configurable)
Screen blinkers (7 pcs) free configurable
Functional keypad comprising 10 push buttons
PC optic interface zone for positioning of specially designed connection cable

The MMI program is a 32-bit application intended to work under WINDOWS® operational system. The connection between the device and PC running MMI software is done trough RS232 interface by means of specially designed connection cable. The PC interface cable can be connected to PC COM port or to USB port through RS232-USB converter. The connection is fully isolated.
The PC interface cable can be connected to the device in one of two ways: by the serial port CANON 9 type positioned on the left side of the device or by the serial port positioned on the front side of the device (by means of magnet – optical head).
The PC based MMI program is designed to make the configuration and setting of the relay easier. It can fulfill the following functions:
Reviewing, changing, saving and setting of the relay configuration and settings;
Reviewing and saving of information from event recorder and disturbance recorder;
Remote commands such as: changing of the working setting group; synchronizing of the real time clock; LED indicators acknowledgment; clearing of the events stored into the device’s memory; changing the CB life time ect.;
Remote control of the main measuring possibilities of the relay – analogue and binary outputs and LED indicators ;
Analysis and documentation of system faults;
Printing of the setting parameters, configurations, recorded events and distur-bance data saved into the relay memory.

Download MMI program