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).