Flameproof circuit breaker type FCB

The flameproof switchgear type FCB is intended for use in workings of underground mines in non-hazardous or hazardous areas, classified as a, b or c level of methane explosion hazard and/or in workings classified as class A or B of coal dust explosion hazard.

It is designed for distribution of electricity in insulated “IT” networks 3×6 kV or 3×3, 3 kV or 3 kV.

The FCB switchgear is a fixed indoor switchgear system designed for both to be combined as multi-feeder switchgear and feeders intended for supplying individual isolated loads.

When combining feeders into multi-feeder switchgear, feeders placed side-by-side are connected with single-core flexible cables routed in metal sheaths. Customers may order the following switchgear versions:

• Incoming feeder identified by the symbol FCB-6/630/2
• Outgoing feeder (motor, cable, or transformer) identified by the symbol FCB-6/200/2.

The switchgear FCB is made up of four flameproof compartments:

• cable(s) (rubber cable) connection compartment for the power supply;
• disconnector and earth switch compartment;
• main compartment equipped with switchgear, measuring, protection and control equipment;
• connection compartment with cable(s) (rubber cables) supplying loads with power;

The main compartment equipment includes the following:

• single-phase auxiliary transformer;
• three current transformers;
• one earth fault transformer (the so-called Ferranti transformer);
• three three-coil voltage transformers;
• self-powered protection unit designed to protect against the effects of phase-to-phase fault, line-to-earth fault and overloads in medium voltage networks;
• vacuum circuit breaker;
• three single-phase surge arresters;
• separators for digital intrinsically safe and non-intrinsically safe control;
• three control switches;
• voltmeter;
• microprocessor controller with a panel to visualising the feeder status capable of recording and viewing events.

The FCB-6/*/2 switchgear is designed for control:

• local;
• remote binary signals;
• digital with visualisation from master dispatching system.

The method of controlling the switchboard is determined by the customer.