i) Sectioning and Paralleling Post:
Explanation of Sectioning and Paralleling Post: 1. The power supply arrangement is as shown in above figure for two track lines between feeding posts and a neutral section. 2. Sectioning and paralleling post consists of two paralleling interrupters used to parallel OHE of up and down tracks, one on the side of neutral. 3. Bridging interrupters is normally kept open unless emergency feed is required. It should only be closed after taking special precautions to warn the drivers to drop the pantograph when passing the feeding post up to which feed is extended. 4. Each substation feeds two sections. 5. Supply to each section is therefore controlled by one CB.
Explanation of Sub Sectioning Post: 1. As shown in above figure each section is subdivided by the provision of one or more sub sectioning posts normally at a distance of every 10km to15km. 2. This facilitates isolation of faulty section. 3. At some stations with large yards change over switch is sometimes provided so that supply may be divided either from OHE of one subsection or the other. 4. There is no interrupter for paralleling the up and down track line