The SIA-B with specific CT’s are Dual & Self powered Overcurrent and Earth Fault Protection Relays, using the operating current through three specific current transformers fitted on the lines.

Thanks to this adaptation the SIA-B relays offers a really reduced dimensions, making this relay easy to install and its light weight helps the customer to save costs in transport.

SIA-B is suitable for RMUs, SF6 insulated and compact switchgears in those installations where the space is critical, making the maintenance much easier.

These transformers are also used to obtain current measurements with the advantage that SIAB relay can be also used with auxiliary power supply (24 Vdc, 110 Vac or 230 Vac). The equipment can be occasionally supplied by an external battery portable kit (KITCOM).

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  • Dual & Self-powered Overcurrent Protection Relay using the operating current through three specific current transformers fitted on the lines, also used to obtain current measurements.
  • The Relay can be used with auxiliary power supply (24 Vdc, 110 Vac or 230Vac).
  • The relay can be occasionally supplied by an external portable adapter (KITCOM).
  • Internal commissioning battery as optional.
  • Its compact size makes SIA-B really easy to install and its light weight helps the customer to save costs in transport.
  • High electromagnetic conpoctibility (EMC)
  • Low power consumption (0.5 W, 24 Vdc).
  • Non-volatile RAM memory in order to store up to 100 events and 4 fault reports, without power supply thanks to its internal RTC (Real Time Clock).
  • USB connection on the front (Modbus RTU communication protocol).
  • Remote communications optional (RS485 Modbus RTU communication protocol).
  • There is an optional bistable magnetic indicator which indicates the trip condition, maintaining their position even though the relay loses the supply (flag).
  • In self powered modes, SIA-B starts-up from 0.4 Is of primary three phase current using specific CTs

50 Phase instantaneous overcurrent

50/51 Inverse time phase overcurrent

50N Instantaneous Neutral overcurrent

50/51N Inverse time Neutral overcurrent

49 Thermal image

49T External trip

TB Trip Block for switch disconnector

Communication Software for SIA & SIL protection relays

The SICom PC software has been designed and programmed to gain access to all of Fanox relays information, to modify the settings and configuration, check states and measurements and to analyse and save events and fault reports using a graphic-friendly user interface.

SICom software works with the Windows® Windows 7, Windows 8, Windows 8.1 and Windows 10 operating system.

  • General data reading: Complete model, Version, Serial number, etc.
  • States reading
  • Measurements reading
  • Reading and changing settings
  • Reading and changing configuration
  • Reading and deleting events
  • Reading and deleting fault reports
  • Reading and deleting demand current (load data profiling)
  • Reading and saving oscillographic records in Comtrade format
  • Changing the user passwords
  • Saving and Loading settings files
  • Saving and Loading configuration files
  • Saving events and fault reports
  • Saving demand current (load data profiling)
  • Date-time synchronization
  • Configuring the communication parameters
  • Reading and changing counters
  • Commands for opening and closing the circuit breaker and block/unblock the recloser
  • Configuration of the inputs
  • Configuration of the outputs
  • Configuration of the causes that start a Fault Report

The update of the software does not require any user´s action, this is, if the computer is connected to Internet, SICom updates itself when it is started.
It will allow you to prepare all the settings and relay configurations without having the relay connected to the PC (offline mode), reducing engineering and commissioning time.
SICom program uses Modbus protocol, so only the ports with this protocol can be used to establish the communication.

Auxiliary Supply24Vdc
24-230 Vac/dc24Vdc
48 Vdc
110-230 Vac/Vdc
24-230 Vac/dc
Self Power Supply3.2A, 6.4A, 12.8A, 25.6A or 51.2A
depending on the CT. (x3)
0,07 In (x3)0,1 In (x3)
External batteryUSB cable / Power bankUSB cable / Power bankKITCOMUSB cable / Power bank
Internal battery√ (*)√ (*)
Consumption0,5 W1,5 W0,5 W1,5 – 2,2 W
CTSpecific CTStandard CT (/1A 2VA)Standard CT (/1 2,5VA; /5 5VA)Standard CT 0,5VA
74TCS 1
Trip Block1111
68 Zone Selection interbloking111
Programmable LogicV3V3V3V3
Sett. Group2443
Inputs132 + EXT.TRIP2
Outputs- / 2NC - NO3 NC - NO2 NC - NO / 3 NO1 NO + 1 NC - NO
Output for STRIKER24 Vdc – 135 mJ24 Vdc – 135 mJ24 Vdc – 135 mJ
LEDs2 LEDs +1MAG.FLAG4 LEDs3 LEDs +3 MAG.FLAGS3 LEDs configurable
HMI20X2 LCD + 7 keys20X2 LCD + 7 keys20X2 LCD + 7 keys20X2 LCD + 7 keys
Fault Report420204
Oscillography10 records x 50 cycles10 records x 50 cycles1 record x 22 cycles
Current demand
Local Port (frontal)USBMicro USBRS232USB
Remote Port (rear)RS485RS485RS485RS485
Communications ProtocolsModBus RTUModBus RTU / DNP3.0ModBus RTU / IEC60870-5-103ModBus RTU / DNP3.0
Size ofVertical: 120,65 x 167,80 mm
Horizontal: 185,80 x 102,7 mm
90 X 245 mmVertical Compact: 177 x 155 mm
Vertical Standard: 177 x 189 mm
Horizontal: 177,8 x 290,3 mm
167,80 x 120,65 mm

Related Products

SIA-B Standard CT’s
Advanced OC&EF Self-Powered Relay

SIA-B is the most reliable dual powered (Self-Powered + Universal Vaux) relay offering a high performance previously available only in relays with Vaux:

Remote communications for SCADA (Modbus or DNP3.0 protocols)

  • Up to 10 COMTRADE records
  • Advanced protection functions
  • Completely configurable I/O thanks to advanced logic

Ultra-fast SOTF
Very low start-up levels and minimum consumption <2 VA
Compact design

Protection functions

  • 50 + 50/51 + 50G + 50/ 51G + 49T + PGC + 49 + SHB + LDP + DFR + 52 + 4 Setting Groups.
  • TB + 46 + 50_2 + 50G_2 + CLP + 50BF as additional protection functions.

Dual & Self-Powered OC&EF Protection Relays

Counting with an extensive experience of successfully operating devices in the field worldwide and thanks to these unique advantages, SIA-C enjoys top recognition among users all around the planet.

Above all, the different mechanics available by model list make our SIA-C the best choice for our customers, covering all the needs of the market

Remote communications RS485 Modbus RTU

  • Self-Powered & Dual-Powered (self+v.aux.)
  • Standard CTs /1 or /5
  • Low start-up levels
  • Load data profiling
  • Self diagnosis (watchdog)
  • Non-volatile RAM memory (up to 1.024 events and 20 fault report), maintaining date & time even in SP mode, thanks to its internal RTC
  • With internal commissioning battery as optional
  • Withdrawable model as optional

Protection functions:

  • 50_1 + 50/51 + 50N/G_1 + 50/51N/G + PGC.
  • 50_2, 50N/G_2, CLP, 79, 52, 49T and 68 as additional protection functions.

SF6 & Metalclad Switchgear Protection Relay

Fanox SIA-F is our most competitive and cost-effective solution for overcurrent and earth-fault protection. Like all other Fanox protection relays the compact size with reduced depth makes it easier to install and saves costs.

Additionally  the use of external CTs allows you to modify their relation adapting to your requirements and reducing installation costs while having a wider range power supply.

Protection functions:

  • 50 + 50/51 + 50N/G + 50/51N/G + 86 + PLC + CLP.
  • 49 + 52 + 50BF + TB as additional protection functions.


FTB/FTP Advantages

FANOX FTB/FTP test block allows testing the protection, control, metering and/or communication device of a facility connected to field switchgear, easily and safely, isolating the circuits fully and eliminating all risks for the user.

  • Maximum safety for the user.
  • Internal automatic CT short circuiting.
  • Single hand fully isolated plug.
  • Locking system for safest operation.
  • Possibility of horizontal or vertical mounting, respectively.