Multifunctional current protection &
remote control
RFI 421

Description
Technical data
Connection diagrams





Description

General information

RFI 421 is intended to be used like a relay protection, automatics and remote control units of follow purposes:
Medium voltage overhead distribution lines
Medium voltage sides of the power transformers
Back-up protection for high voltage side of the power transformers
Motor protection and ect.

Event Recorder and Disturbance Recorder functions are integrated into the device. Communication with SCADA or substation controller equipment (work station) is available. The connection can be done via serial interfaces through the choice of data cable, modem, or optical fibers.

RFI 421 includes up to 4 selectable setting groups. Transition from one setting group to another can be done during exploitation of the device.
locally - trough the front device's keypad
remotely - by running MMI-service program or by command from work station
via dedicated binary inputs


Relay protection functions

Definite time delay overcurrent protection (ANSI 50, 51)

 

Non-directional time delay overcurrent protection with definite time;
Possibility for acceleration before or after autoreclosing;
Possibility for acceleration in case of remote or manual circuit breaker (CB) closing;
General settings
Curent relays type - phase or phse-tophse relays
Setting Ipick-up - (0,10 ... 40,00).In
Setting of time delay - 0,00 ... 100,00 s
Acceleration from Autoreclosing: 0,00 ... 10,00 s
Acceleration from manual or remote close: 0,00 ... 10,00 s
Operating time: < 30 ms

Instantaneous overcurrent protection (ANSI 50, 51)
 

Non-directional instantaneous (or with time delay) overcurrent 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 circuit breaker closing
General settings
Curent relays type - phase or phse-tophse relays
Setting Ipick-up - (0,10 ... 40,00).In
Setting of time delay - 0,00 ... 100,00 s
Acceleration from Autoreclosing
Acceleration from manual or remote close
Operating time: < 30 ms

Inverse time delay overcurrent protection (ANSI 51)

 

Non-directional inverse time delay over-current 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
General settings
Curent relays type - phase or phse-tophse relays
Setting Is,pick-up - (0,10 ... 10,00).In
Current delay time ratio Ks - 0,05 ... 5,00 s
Operating time: < 30 ms

Overcurrent earth fault protection (ANSI 50N, 51N)

 

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 CB closing for each stage separately.
Residual current relay - settings
Stage 1 - (0,10 ... 100,00)Iîn
Stage 2 - (0,10 ... 100,00)Iîn
Stage 3 - (0,10 ... 100,00)Iîn
Time delay - settings:
Stage 1 - 0,00 ... 100,00 s
Stage 2 - 0,00 ... 100,00 s
Stage 3 - 0,00 ... 100,00 s

Inverse time delay earth fault protection (ANSI 51N)

 

Non-directional inverse time delay earth fault 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
Settings
Curent relays type - phase or phse-tophse relays
Setting Is,pick-up - (0,10 ... 10,00).In
Current delay time ratio Ks - 0,05 ... 5,00 s
Operating time: < 30 msÍàñòðîéêà íà òîêîâîòî ðåëå

Thermal overload protection (ANSI 49)

 

Uses a thermal model of the line, based on its heating and cooling time con-stants 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 pick-up with a delay which depends on the degree of overload;
The protection has two stages providing trip and pre-trip alarm outputs.
Settings
Setting of thermal status for alarming level: 10 ... 150 %
Setting of thermal status for tripping level: 10 ... 200 %
Setting of the thermal time constant 2,00 ... 99,00 min
Operating time: < 30 ms

Negative sequence overcurrent protection (ANSI 46)

 

Evaluation of negative sequence component of the currents;
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 (e.g. with the switch group ?y 5). This provides backup protection for high-resistance faults beyond the transformer. To detect the unbalanced load, the ratio.
Settings
Current relayl: (0,1 ... 20,00).In
Tripping delay time setting - 0 ... 100 s
Operating time: < 30 ms

Autoreclosing (ANSI 79)

 

Up to six shot AR:
AR starting conditions - at tripping command issued of internal or external protection function or at the circuit breaker and control switch positions discrepancy.
AR blocking conditions - tripping by load shedding or other external equipment, manual closing of the circuit breaker or remote remote control command for closing or opening the breaker.

Breaker failure protection (50 BF)

 

The breaker failure protection function monitors the reaction of a circuit breaker to a trip signal from of any integrated (internal) protection;
Breaker failure detects activation of the configured binary outputs
If after a programmable time delay, the circuit breaker has not opened, breaker failure protection issues a trip signal via a super ordinate circuit breaker

Circuit breaker life time monitoring

 

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

Each protection function can be set ON or OFF.


Data aquisition & remote control functions

Remote measurement

  Measures, processes and archives information about instant and integral values for the analogue quantities of the protected feeder;
Calculates the average “rms” values of the voltage for each second and sends them through the local network to the connected PC work station (WS)
Sends the data to the WS for maximal registered values
The measured analogue values are displayed continuously on the LCD of the device.

Remote control

  The function permits direct control of the feeder’s circuit breaker and disconnectors in two ways – by means of SCADA-system (remote control commands from work station PC received trough the local network) or initiated by pressing of spatially designed push buttons “I” and “O” situated on the device’s front panel.

Remote signalization

RFI 421 receives processes and archives the following information:
Primary equipment status change
Warning and alarm signalization received from external devices for relay protection and automation – operation of load shedding relays and auxiliary power supply failure relays, for example
Pick-up and drop-off of the voltage relays of the internal relay protection functions
Trip commands sent to the CB from internal relay protection functions
Alarm signalization related to the remote control function operation (CB or disconnectors) – failure in execution of the remote control command, attempt for not permitted command issuing and etc.
Signalizations for controlled values limit overreaching
The device time synchronizations (by front panel or remotely)
Changing of the working parameters of the device (new configuration, new re-lay protection settings and new parameters for remote control functions)
Clearing of the data from Event Recorder or Disturbance recorder


Event Recorder function

 

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

Disturbance Recorder function

  For each of the event included into the Event recorder can be set to initiate additional more detailed oscillographic data collection. The period of the data collection consist of two intervals pre-history duration and during the fault. These records consist of all measured and calculated analogue values (wave-form), binary inputs and outputs and processing points. The values recorded are measured with maximal sampling frequency of the device. The records from the Disturbance recorder function can be transferred to the connected PC running MMI service program. On the Work station PC (SCADA-system) the information recorded can be added to the archive displayed in graphical way and used for detailed analysis of the primary events and the behavior of the relay protections and primary equipment.

Working in SCADA-system

 

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.

Human Machine Interface (HMI)

 

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

Man Machine Interface - MMI

 

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



Technical data

POWER SUPPLY

  
Rated voltage, Un

24 … 48 DC/AC (-20% ... +20%)
24 … 110 DC (-20% … +10%)
110 V DC/AC (-20% ... +20%)
220 V DC/AC (-20% ... +20%)

DC supply interruption

According to IEC 60255-11:
0,1 s / 100 % at 110/220 V
0,01 s / 100 % at 24 V

Burden

6 W

ANALOG INPUTS

  

Frequency

  
-rated values fn 50 Hz (option 60 Hz)
-operational range 46 ... 52 Hz
Current inputs 4 pcs.
Rated current, In 5 À / 1 À
Consumption <0,05 VA at In = 5A
<0,03 VA at In = 1A
Thermal current withstand
(acc. IEC 60255-6, IEC 60255-3)		 continuous - 10.In,
for 1 s – 100.In
for 10 ms - 250.In
Range of precise operation (0,1 ... 40).In

BINARY INPUTS

  

Total number

 4 pcs. 

Auxiliary power supply

  

- Rated voltage

24/48/110/220 V DC

- Operational range

 176...342 V DC at Un=220 V DC
65 ... 171 V DC at Un=110 V DC

Burden in each input circuit

0,7 W at 220 V DC

BINARY OUTPUTS

 
Total number 5 pcs.
Electromechanical relays with NO/NC contacts 8 À max
250 V AC / DC max
2 000 VA
< 10 ms operation time

CONSTRUCTION

  

External part Metal welded box

 

Flush mounting

  

Dimensions

300 mm x 195 mm x 51 mm

Weight

2,5 kg

Protection degree (acc. IEC 60529)

IP52 (front panel)

Surface mounting

  

Dimensions

317 mm x 256 mm x 55 mm

Weight

3 kg

Protection degree (acc. IEC 60529)

IP52 (front panel)

INTERFACES

  

Communication protocols:

IEC 60870-5-103, IEC 60870-5-NEO

RS485 electrical

38,4 kbit/s max

RS232 current loop / optical head

9,6 kbit/s

ELECTRICAL TESTS

  

Insulation Tests

IEC 60255-5, class 3
High Voltage Test

2 kV; 50 Hz; 1 min

Impulse Voltage Test

5 kV; 1,2 / 50 ms; 0,5 J

Insulation Resistance Test

>100 MW ; 500 V DC
   

ELECTROMAGNETIC COMPATIBILITY (EMC)

  

EMC – disturbance immunity

  
High frequency disturbance IEC 60255-22-1; EN 61000-4-12, class 3

Electrostatic Discharge

IIEC 60255-22-2
EN 61000-4-2, class 4

Radio-frequency Electromagnetic Field:

IEC 60255-22-3; EN 61000-4-3, class 3

Fast Transients

IEC 60255-22-4,
EN 61000-4-4, class 4

Surge immunity

IEC 60255-22-5; EN 61000-4-5, class 3

Conductive radio disturbances

IEC 60255-22-6; EN 61000-4-6, class 3

Power frequency magnetic field

EN 61000-4-8, class 4
   

EMC - emissions

 IEC CISPR 11, class A

 

 

MECHANICAL TESTS

  

During operation

  

Vibration

IEC 60255-21-1, class 1; IEC 60068-2-6

Shocks

IEC 60255-21-2, class 1; IEC 60068-2-27

Seismic tests

IEC 60255-21-3, class 1, IEC 60068-3-3

During transport (with standard package)

  

Vibrations

IEC 60255-21-1, class 1; IEC 60068-2-6

Shocks

IEC 60255-21-2, class 1; IEC 60068-2-27

Bump

IEC 60068-2-29
AMBIENT CONDITIONS  

During transportation and storage

IEC 60068-2-1; IEC 60068-2-2

– During transportation and storage

-40 ... +70 ° C

– During exploitation

-25 ...+55 ° C

Relative air humidity

 IEC 60068-2-78: 95% at 40 ° C

 

Connection diagrams
Mounting dimensions of the device are given on fig. 1. The electrical connection diagram is shown on Fig. 2.