SIA-C Dual & Self-Powered Protection Relays

SIA-C Relays are Dual & Self powered overcurrent and earth fault Protection Relays, that obtein the energy to power itself tanks to STANDARD CURRENT TRANSFORMES on the lines. Besides, due to the low consumption of this relay, the required burden of the CTs is very low (2.5 VAs for 1 A nominal current or 5 VAs for 1 A nominal current.

SIA-C is provided with a really low pick-up level (0.1xIn) and its complete electronic allows to record up to 1024 events and 20 fault reports which are saved with the date and time at the moment of the recording thanks to the internal real time clock (RTC).

On the other hand, the SIA-C can be also Dual-powered Relay (working with auxiliary voltage) and offers up to 3 configurable LEDs and up to 3 magnetic indicators to signal the trip.

Regarding the communication and depending on model, rear communication (RS485 – Modbus RTU) can be selected.

Considering these advantages, SIA-C can be used in multiple applications, and different mechanics have been developed to cover all clients’ requirement.

Main Applications: Transformation substations. RMUs and SF6 insulated Switchgears.

Contact us

Country (required)

Your First Name (required)

Your Last Name (required)

Your Email (required)


Your Message

This site is protected by reCAPTCHA and the Google
Privacy Policy and
Terms of Service apply.

The SIA-C is a overcurrent protection relay with self powered and dual powered (Self + Auxiliary) models.

  • The relay is self powered using the operating current through three /5 (5VA) or /1 (2.5VA) standard current transformers fitted on the lines. These transformers are also used to obtain current measurements. Optionally, SIAC relay can be used with auxiliary power supply (24 Vdc, 230 Vac, 48 Vdc or 100-230 Vdc/ac).
    The equipment can be occasionally supplied by an external battery portable kit (KITCOM).
  • Internal Commissioning battery as optional. (Lithium battery: 20 years lifetime).
  • 50_1, 50/51, 50N/G_1, 50/51N/G, 74TCS, PGC, 50_2, 50N/G_2, CLP, 49, 46, 46BC, 50BF, 74CT, 79, 52, SHB, 49 and 68 protection functions.
  • Specific test menu is provided.
  • Remote communications RS485 Modbus RTU or IEC 60870-5-103
  • High electromagnetic compatibility.
  • The installation and subsequent maintenance of batteries is eliminated. The operating costs of the centre are reduced.
  • In self powered modes, the start-up of the relay from 0.1 times of the nominal current in three phases ensures capacity to trip at low energy levels.
  • The line opening mechanism is activated either by means of a striker PRT, operated by the energy supplied by the relay itself, or by a coil using the TCM trip adapter in case it is necessary.
  • There are bistable magnetic indicators which indicate the trip cause, maintaining their position even though the relay loses the supply (flags).
  • Different sizes of SIA-C relay available by model list to fulfil all the needs of our customers and make the installation easier.
  • SIA-C is fitted with the demand of current (Load Data Profiling) with the following characteristics:
    • Number of records: 168
    • Recording mode circular
    • Sampling rate (interval): configurable through communications: 1 – 60 min
  • Non-volatile RAM memory in order to store up to 1.024 events and 20 fault report, maintaining date & time, thanks to its internal RTC (Real time clock) even without power supply.

50 Instantaneous Phase Overcurrent
50/51 Phase inverse time overcurrent
50N/G Neutral instantaneous overcurrent measured/calculated
50/51N/G Inverse time neutral overcurrent
49T External trip
52 Circuit Breaker Monitoring
79 Recloser
68 Zone selection interbloking
CLP Cold Load Pick-up
46 Negative Sequence Instant overcurrent
49 Thermal Image
50BF Circuit Breaker Opening Failure
46BC Broken Conductor Detection
74CT Phase CT Supervision
74TCS Trip Supervision PGC
SHB Second Harmonic Blocking
PGC Programmable Logic Control

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
Dual & Self-Powered Protection Relays

Standard /1 CTs

Fanox SIA-B Standard CT’s is our best solution for last generation switchgears where the available space is critical thanks to its reduced dimensions. This feature combined with the use of standard /1 CTs allows it to fit into almost every actual switchgear. Protect your installation with the highest precision thanks to oscillographic records plus extra events and fault records, requiring minimum current levels for the relay to start.

SIA-B Specific CT’s
Dual & Self-Powered Protection Relays

Specific CTs

Fanox SIA-B Specific CT’s is our affordable solution for overcurrent protection. This series is the perfect choice if you look for a competitive and complete solution composed by relay + CTs for overcurrent protection while having all functions required for a maximum safety.

SF6 & Metalclad Switchgear Protection

Fanox SIA-F is our most competitive and economical solution for overcurrent and earth-fault protection. The use of external CTs allows you to modify their relation adapting to your requirements and reducing installation costs while having an extender range power supply.