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Advanced Protection and Control Devices
for Substations and Switchgears 1 - 45 kV



A wide range of protection
and automation functions


Combined power supply
including CT circuits unit


Backup trip via CB
current solenoids


Digital oscilloscope
Event log


Integration in


Environment temperature


User-defined logics inclusion
available (on demand)


Fast-operating arc fault
protection with lens-type


New modified electronic microprocessor devices series RZL-05 are used for protection, automation, control and monitoring of power distribution network elements. Devices are the most suitable for incoming / outgoing feeder (RZL-05.Ax B) and busbar section coupler (RZL-05.Ax BS) bays of 1 - 45 kV distribution networks.

Devices can be installed in relay cubicles of switchgear bays.

# Download the catalog. Relay Protection and Automation Devices.


  • Protection, automation and control of an intended network elements;
  • Operating parameters settings via built-in HMI and PC software tool: functions activation/deactivation, protection stages values and time delay for each stage etc.;
  • Three photosensor inputs of arc-fault protection;
  • Each photosensor input independent configuration;
  • Fault recorder and event log;
  • Total fault record duration over 600 s;
  • A solid number of inputs, outputs and indicating LEDs;
  • Flexible configuration settings;
  • Non-volatile storage of setting, events, fault recordings;
  • Data transfer including current parameter and function settings, apparatus state, events, measurements;;
  • Remote control functions;
  • Wire connection terminals with end-position locking plug;
  • Steel casing;
  • Front side USB interface;;
  • Two RS-485 interfaces of MODBUS data transfer protocol;
  • Real-time self-supervision;
  • Self-blocking on internal failure to prevent false operations;
  • Two mutually redundant power supply units;
  • Optional current circuits low-burden redundant power supply;
  • AC/DC power supply source;
  • Binary inputs optocoupler isolations;
  • Supply inputs and all signal circuits are galvanically isolated;
  • Solid overvoltage withstand;
  • Solid ambient conditions withstand;

Technical parameters

Power supply units parameters
Operating voltage range, DC or AC 90 - 254 V
Power-on availability time 0,19 s
Operating supply interruption 0,5 s
Independent supply channels (auxiliary voltage circuits) 2
Device burden 10 Wt
Supply from current transformer circuits (optional) 2
Continuous current withstand 2,5 - 20,0 A
Current input parameters
Rated input current 5A
Line current inputs number 3
Measurable current range 0,3 - 200,0 A
Current thermal withstand, 1 s 10 (500) A
Rated zero-sequence input current (3Io) 1 A
Measurable current 3Io range 0,01 - 4,00 A
Voltage input parameters
Phase voltage 100 V
Number of inputs 3
Rated voltage range 1 - 150 V
Maximum continuous voltage 130 V
Thermal sensor input parameters
Number of inputs 1
Temperature range 0 - 125 °C
USB interface 1
RS485 interface 2
Data protocol Modbus RTU
Connection speed 9600, 19200, 38400 kbps
Binary input parameters
Numbers of inputs 17
Rated AC, DC voltage 230 V
Response voltage level 132 - 176 V
Response time 40 ms
Current consumption at 220 V:
- power-on current
- continuous

20 mA<
4 mA
Maximum voltage, continuous 310 V
Dry contact binary input parameters
Number of inputs 3
Dry contact circuits source voltage, DC 24 V
Binary output parameters
Number of binary outputs 17
Maximum DC voltage trip 300 V
Maximum AC voltage trip 400 V
Maximum AC current 8 A (16 A for K1 output)
Maximum DC LR-circuit trip current, time constant τ ≤ 20 ms 0,3 A (0,6 A for K1 output)
Mounting type Flush
Device dimensions (WxHxD) 265x240x190 mm
LED indicators    total / configurable 20/8
Operating ambient temperature range
-40 to +55 °C
Maximum Humidity at 25 °C 98%
Insulation resistance, more than 50 MΩ
Insulation overvoltage withstand,
Instantaneous / continuous

5 / 2 kV
Weight, less then 10 kg


Function ANSI RZL-05.Ax B RZL-05.Ax BS
Protection   1 2 3 4 1 2 3 4
Overcurrent (OCP) 50/51
Voltage-restrained OCP 50V/51V
OCP stage blocking by binary input  
Directional OCP 67
Negative-sequence overcurrent 46
Switch on to fault high-speed protection 50HS
Logic Selectivity Busbar protection 68
Zero-sequence OCP (unidirectional ground-fault protection) 50N/51N        
Directional ground-fault protection (directional zero-sequence power protection) 67N        
Zero-sequence overvoltage protection 59N
Overvoltage protection 59
Undervoltage protection with a current-permissive instance 27
Negative-sequence overvoltage protection 47
Phase conductor break protection (negative sequence or negative to positive sequence ratio cirrent) 46BC
OCP/zero-sequence OCP stage activation by binary signal (current-restrained intertrip)  
ARC-fault protection (3 optofibre sensor inputs)          
Overtemperature protection  
Automation functions    
Auto-reclosing 79        
Automatic underfrequency load shedding 81L        
HV Breaker failure back-up 50BF
Automatic load transfer  
Automatic initial scheme restore  
Monitoring and indication functions    
Breaker closing circuits supervision 74TCS
Temperature monitoring via thermal sensor 38/49T
Protection operation alarm lockout (LED and output state save until manual reset)  
Internal malfunction alarm 30
Voltage transformer secondary circuits supervision  
Parameter setting groups switch on binary input activation/deactivation  
Service functions    
Non-volatile memory event log  
Non-volatile memory fault recorder with 600 s total record duration  
Fault recorder on binary input activation  

Wiring Diagrams

RZL-05.A4 B - wiring

Wiring diagram of external circuits to the devices RZL-05.A4 B

RZL-05.A3 BS - wiring

Wiring diagram of external circuits to the devices RZL-05.A3 BS


RZL-05_A - dimensions

RZL-05_A - back

# Download the catalog. Relay Protection and Automation Devices.