SAFETY in SUB-STATIONS
SAFETY MEASURES IN ELECTRIC SUB-STATION
1) Clear independent approach to the sub-station from outside the building shall be made available round the clock
2) The approaches/corridors to the sub-station area shall be kept clear for movement of men and material at all times.
3) The sub-station space is required to be provided with proper internal lighting arrangements.
4) In addition to natural ventilation proper ventilation to the sub-station area is to be provided by grill shutters and exhaust fans at suitable places so as to discharge all smoke from the sub-station without delay in case of fire so that sub-station operations can be carried out expeditiously.
5) Cable trenches of 0.6 m. X 0.6 m. dummy floor of 0.6 mt. depth shall be provided to facilitate laying of cable inside the building for connecting to the equipment.
6) Steel shutters of 8’X 8’ with suitable grills shall be provided for transformers and sub-station room.
7) The floor of the sub-station should be capable of carrying 10 tons of transformer weight on wheels.
8) Built up substation space is to be provided free of cost.
9) Sub-station space should be clear from any water, sewer, air conditioning, and gas pipe or telephone services. No other service should pass through the sub station space or the cable trenches.
10) Proper ramp with suitable slope may be provided for loading and unloading of the equipment and proper approach will be provided.
11) RCC pipes at suitable places as required will be provided for the cable entries to the sub station space and making suitable arrangement for non-ingress of water through these pipes.
12) The sub station space is to be provided in the approved/sanctioned covered area of the building.
13) Any other alteration /modification required while erection of the equipment will be made by the Owner / builder at site as per requirement.
14) Adequate arrangement for fixing chain pulley block above the fixing be available for load of 15 tons.
15) Provision shall be kept for the sumps so as to accommodate complete volume of transformer oil, which can spillover in the event of explosion of the transformer in the basement of the building. Sufficient arrangement should exist to avoid fire in the sub-station building from spread of the oil from the sumps.
16) Arrangement should be made for the provision of fire retardent cables so as to avoid chances of spread of fire in the sub-station building.
17) Sufficient pumping arrangement should exist for pumping the water out, in case of fire so as to ensure minimum loss to the switchgear and transformer.
18) No combustible material should be stacked inside the substation premises or in the vicinity to avoid chances of fire.
19) It should be made mandatory that the promoters of the multi-storeyed building should get substation premises inspected once a year to get their license revalidated for the provision of electric supply from Electricity Board so that suitable action can be taken against the Owner / Builder in case of non- implementation of Bye-Laws.
20) The sub-station must not be located below the 1st basement and above the ground floor.
21) The sub station space should be totally segregated from the other areas of the basement by fire resisting wall. The ramp should have a slope of 1 : 10 with entry from ground level. The entire Sub-station space including the entrance at ground floor be handed over to the licensee of electricity free of cost and rent.
22)The sub-station area shall have a clear height of 12 feet (3.65 m.) below beams. Further the Sub-station area will have level above the rest of basement level by 2 feet.
23)It is to be ensured that the Sub-station area is free of seepage / leakage of water.
24) The licensee of electricity will have the power to disconnect the supply of the building in case of violation of any of the above points.
25) Electric sub station enclosure must be completely segregated with 4-hours fire rating wall from remaining part of basement.
26) The Sub-station should be located on periphery /sub basement and (not above ground floor).
27) Additional exit shall be provided if travel distance from farthest corner to ramp is more than l5 m.
28) Perfect independent vent system 30 air changes per hour linked with detection as well as automatic high velocity water spray system shall be provided.
29) All the transformers shall be protected with high velocity water spray system / Nitrogen Injection System Carbon Dioxide total flooding system in case of oil filled transformer. In addition to this, manual control of auto high velocity spray system for individual transformers shall be located outside the building at ground floor.
30) Suitable arrangement for pump house, water storage tanks with main electrical pump and a diesel-operated pump shall be made if no such arrangement is provided in the building. In case the water pumping facilities are existing in the building for sprinkler system, the same should however be utilized for high velocity water spray system. Alternatively automatic CO2 total flooding system shall be provided with manual controls outside the electric sub-station.
31) System shall have facility to give an audio alarm in the basement as well as at the control room.
32) Fire control room shall be manned round the clock.
33) The electric sub station shall have electric supply from alternate source for operation of vent System lighting arrangements.
34) Cable trenches shall be filled with sand
35) Party walls shall be provided between two transformers as per the rules.
36)Electric control panels shall be segregated.
37) Exits from basement electric substation shall have self-closing fire smoke check doors of 2-hours fire rating near entry to ramp.
38) All openings to lower basement or to ground floor shall be sealed properly.
39) Yearly inspection shall be carried out by electrical load sanctioning Authority.
40) Ramp to be designed in a manner that in case of fire no smoke should enter the main building.
41) Electric sub station transformer shall have clearance on all sides as per BBL/relevant electric rules.
42) Other facility will be as per Building Bye-Laws and relevant electric rules.
43) Rising electrical mains shall consist of metal bus bars suitably protected from safety point of view.
44) Oil less transformer shall be preferred.