Railway signalling within the rail network is of critical importance to ensure intrinsic safety and reliability. There are two circuits in the rail system – the 110V bus and 60V bus – which are responsible for the mechanical shift of a portion of track, to route locomotives accordingly and the latter is responsible for safety interlocks which cannot be interrupted during a surge or power failure.
Due to the critical nature of this application, long and reliable service batteries are required. For decades First National Battery has been supplying the Chloride Plante and Flat plate design batteries to ensure continuity of supply.
Signalling relay rooms comprise of two battery banks, namely: 110V and a 60V battery.
The 100V DC bus supplies a rotary motor which generates 380V AC to drive a points motor to mechanically shift a track to a required position for a locomotive to change tracks.
The 60V DC bus plays an instrumental role in ensuring that safety interlocks within integrated signalling equipment are not interrupted during a power failure. All safety interlocks are driven by very reliable relay logic. Safety interlocking within the railway system is a mission critical application to ensure intrinsic safety within the rail system. Battery autonomy for signalling equipment is normally between 5 to 8 hours.