Emergency Tripping Systems

Emergency Tripping System (ETS) is used to achieve an electrical tripping scheme to de-energise the OCS section during emergency conditions. ETS will cover the entire underground portion of Line-3.

Emergency Tripping System consists of ETS stations (ETS Boxes) and the PLC/RTU which is a part of the SCADA System. Upon activation , ETS will proceed through a pre-determined programme of operation of Circuit Breakers and relevant interrupters to de-energise the OSC Sections. Further, it will interface with signalling and the essential interlocking to prevent any train coming on directly or through a cross over leading to the affected OCS section where ETS has been activated.


The main features of the ETS are :

a) Electrical Tripping

b) Communication through Hotline

The Emergency Tripping System enables electrical tripping of power supply of the traction time in case of emergency. This is achieved by breakage of the glass fitted on the front cover of the ETS Box, opening of the front cover using the handle provided inside and pressing of the Emergency Push Button (EPB). This action will trip the 25KV Traction time through a pre-determined operation of circuit breakers and relevant interrupters to de-energise the corresponding section.


Break Glass with Hammer.

Press the handle downward to open Door.

Press the Push Button Switch to Trip off 25KV traction Line.

Lift telephone receiver to communicate.