The Feeder Cubicle supplies power and protects the traction line. Inside the cubicle there is the withdrawable High Speed DC Circuit Breaker truck mounted.

In the unit, the circuit breaker may be in one of the following positions:

-Connected: normal operating position, all circuits are connected;

- Isolated (test condition): power circuit are disconnected and auxiliary circuit are connected.

- Isolated (out of service) : both power and auxiliary circuits are disconnected.

On customer request, the Feeder Cubicle can be equipped with:

- Line test relay type DIA-LP;

- Protection and diagnostic relay type DIA-IGTV;

- Voltage and current measurement eqiupments;

- Earthing switch;

- Line disconnector;

- Frame protection relay (64).