Page 378 - IRSEM_Main Book

(g) AC supply for signal transformers shall be derived from a voltage regulator of
approved type.

(h) Separate Transformer shall be used for feeding signals and track feed
chargers.

(i) The current rating of battery charger may be derived from the following
formula - Current rating of charger = Load current + AH/10 capacity of cell.

(j) Battery chargers shall not directly feed the line circuit of Block Instruments.

Section 5: Installation of Secondary Cells

16.5.1 Charging & Installation

(a) Secondary cells of approved type shall be used. The cells shall be installed
as per approved drawings.

(b) The batteries shall be installed in separate room/apparatus case to avoid
damage to power equipment due to fumes. The battery room shall be
provided with acid proof flooring and acid proof tiles on walls up to a
suitable height. The battery room shall be well ventilated and provided with
exhaust fan(s).

(c) The batteries shall be so installed that they are away from direct rays of
sun and any heat radiating equipment.

(d) The batteries shall be installed on wooden racks/insulated masonry surface
of suitable height with acid proof tiles to permit easy access for
maintenance. The racks shall be protected by two or more coats of acid
resistant paint of approved type. The racks shall be level and mounted on
approved type of insulators. Where batteries are housed in location boxes,
these housings shall be painted with acid resistant paint and shall have
suitable openings/holes for ventilation.

(e) The batteries shall be kept properly aligned and suitably numbered. An
adequate clearance shall be kept between the cells.

(f) Initial charging of the batteries shall be done as per instructions of the
manufacturer and the date of charging shall be suitably painted on the
batteries, or on a separate board kept near the batteries.

(g) Battery grade sulphuric acid conforming to IS 266, diluted with distilled
water conforming to IS 1069 shall only be used as electrolyte.

(h) A glass, porcelain, rubber or any other acid proof container shall only be
used for mixing acid and water. Metal utensils except lead must not be
used as these will contaminate the electrolyte.

Chapter 16: Power Supply Systems for Signalling Installations Page 326 of 535