Floor opening of 760 mm x 760 mm leading to basement where required, are to be provided with an appropriate galvanized chequer cover. Cat ladders are to be provided at floor openings. Details of these must be shown on drawings.
Basement where required must be at least 1.8 m clear height and its floor level must be equal to higher than the surrounding final main road level.
Basement door (if applicable) shall be fixed with a panic bolt of the approved type.
Positions and details of plant and cable duct opening s as shown on drawing are subject to verification on site.
Cable trenches, ramps and cable entry ducts are to be supported by pilling where necessary. Cross sectional views must be shown on drawing.
Cable trenches of a minimum depth 900 mm and a minimum width of 600 mm are to be provided. The trenches are to be filled with sand.
Cable trenches and switch gear floor openings are to be covered with removable galvanized chequer plate each of 8 mm thickness and 300 mm width.
All cable trenches and substation basement (if applicable) must be dry and free of water. Water proof sealing compound shall be used.
The value of the minimum bending radius of the various types of cables shall be complied with.
The schematic layout of the light fittings, power points, etc shall be shown in the drawing.
An illumination level of above 400 lux is required. External lighting for substation building shall be controlled by a time switch.
A minimum of 2 numbers of switched power socket putlets each are required for the transformer and switch gear rooms.
All substation wiring shall be run in surfaced G.I. conduits.
A rubber mat to B.S. 5912/1952 or equivalent, of minimum thickness of 5 mm and width 600 mm shall be provided in front of the switch gear.
Fire fighting requirements shall be approved by the Fire Department as well as SESCO are as follow :-
A. For up to 1000 kVA capacity, 1 unit each of CO2 fire extinguisher of the approved type is to be provided and mounted in transformer, switch gear and battery room.
B. For greater than 1000 kVA capacity, a CO2 gas fire fighting system of adequate capacity with smoke and heat detectors are to be installed in the transformer and switch gear
Switch gear room and transformer room must be designed to provide adequate ventilation. Honeycomb walls or p.c. RC louvers, where applicable, are to be used for transformer capacities up to 1000 kVA.
For substation above 1000 kVA capacity, a time controlled exhaust fan of adequate capacity is to be installed separately in both transformer and switch gear rooms.
Substation name plate and danger sign are to be mounted at the substation door
The substations shall be earth filled to a height of at least 300 mm above the final flood level or above the height of the surrounding area.
The substation fencing shall be as follows :-
(A) Chain link perimeter fencing of 3 m height shall be galvanized to B.S.729 and B.S.443 inclusive of 3 rows of barbed wire at the fence top.
(B) The base of the fencing shall be embedded in a concrete kerb of 150 mm depth and 100 mm width.
(C) All metal structures which from the fencing shall be separately earthed.
(D) An apron of minimum 600 mm shall be provided surrounding the perimeter fence externally.