In terms of its products lines, Fanox feature internaltianally approved SIA-B and SIA-C Relays. These Self-powered Overcurrent and Earth-fault Protection Relays are designed to protect Secondary Transformer Stations and Distribution Centers of Electrical Networks with independence and free of maintenance.


SIA-B and SIA-C have been designed with a very compact size, to cover all customer requirements and make installation easier, faster, cheaper and more reliable. Optionally you can have an auxiliary power supply in addition to self-powered function.


The SIA-B relay, as SIA-C, is Self-Powered from the power lines and both relays use STANDARD current transformers. The need for batteries and any maintenance is eliminated, reducing the operating cost of the center considerably.


Additionally,  the equipment can be connected to an external portable accessory (KITCOM) for commissioning and setting up office through the front communication port. The possibility of powering up with the KITCOM accesory, offers the possibility to activate the trip contact from the test menu, allowing the verification of the circuit breaker before energizing the switchgear.

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

Specific CTs

Fanox SIA-B Specific CTs is a powerfull solution for overcurrent protection. This relay 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.

Protection functions:

  • 50 + 50/51 + 50N + 50/51N.
  • 49 + 49T + TB as additional protection functions.

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

SIA-B is a 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 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 + 50N + 50/ 51N + 49T + 86 + PLC + 49 + SHB + LDP + DFR + 52 + 4 Settings Groups.
  • TB + 46  + 50_2 + 50N/G_2 + CLP + 50BF as additional protection functions.

Dual & Self-Powered Protection Relays

Standard /1 or /5 CTs

Fanox SIA-C possibility of working with both /1 and /5 standard CTs makes it our safest choice for overcurrent and earth fault Protection. Different sizes and models besides being withdrawable and Self-Powered makes the installation and maintenance much easier and simple. It also allows you to adapt some monitoring and auto-recloser functions in order to have some extra control and wider protection.

Protection functions:

  • 50 + 50/51 + 50N/G + 50/51 N/G + 86 + PLC.
  • 49T + CLP + 68 + 50_2 + 50N/G_2 + 52 + 79 + 3 Settings Groups as additional protection functions.