distribution design

1. Electric Distribution
In a Large Campus

11. Up to 100 kVA - 415 Volts
100 kVA to 1 MVA - 11kV
1 MVA to 5 MVA - 11 kV
5 MVA to 10 MVA - 33
10 MVA to 20 MVA – 66 KV
20 to 45 MVA - 132 KV

15. 33 KV / 11 KV outdoor substation

18. 33 kv /11 kv Substation with generating sets

20. Sectional Elevations 33/ 11 KV Main Receiving
Station 3500 KVA Capacity

23. Substations in Societies – Unsafe way

31. Oil Conservator
Radiator
Incomming
Bushings

38. HT Panel 33 or 11 KV

41. Automatic Transfer Switch (ATS) Panel

79. 33KVA MAIN RECEIVING
SUBSTATION -1
(8 MVA)
2 X1500 KVA Tr
11 KV/433V
2 X1500 KVA Tr
11 KV/433V
Near CADT. ACCN.
2 X1500 KVA Tr
11 KV/433V
In Indoor
Stadium
2 X1500 KVA Tr
11 KV/433V
Head Quarter
Building
EXISTING SUBSTATION
2X1000 KVA Tr
33 KV/433 V
Electrical
–
Substation
&
Distribution
Area
Diagram

80. Electrical
–
Substation
Distribution
Line
Diagram
without
map

82. Electrical Disribution and Substations
The total maximum demand of the campus is estimated to be
as 6.34 MVA for which a Main receiving station of 33 kv/11
KV shall be necessary feeding further 4 more substations in
the campus in addition to existing one.
Main Receiving Substation (1) KVA Proposed Transformers
Maximum Demand of Substation-1a 2301.93 2 x 1500 KVA 11/0.433 KV Transformers
Maximum Demand of Substation-2 2069.81 2 x 1500 KVA 11/0.433 KV Transformers
Maximum Demand of Substation-3 2314.90 2 x 1500 KVA 11/0.433 KV Transformers
Maximum Demand of Substation-4 2065.89 2 x 1500 KVA 11/0.433 KV Transformers
Maximum Demand of Substation 5 1000.00
2 x 1000 KVA 33/0.433 KV
Transformers Already Existing
Total 9752.52
Assumed Simultaneous Diversity
Factor
0.65
Maximum Demand of Substation-1 6339.14 3 x 4000 KVA 33/11 kv

84. Mini Secretariate Alwar

85. Civil Engineers’ Role in Construction of External
Substation
1) Construction of Boundary wall of switch Yard
2) Storm water drainage and sewage disposal
3) Construction of Fire Proof partition walls among
transformers
4) Path ways
5) Construction of Soak Pit
6) Indoor Portion of Substation Building

86. The substation should preferably be located in separate building and
could be adjacent to the generator room, if any. Location of
substation in the basement floors should be avoided, as far as
possible.
The ideal location for an electrical substation for a group of
buildings would be at the electrical load centre on the ground floor.
The floor level of the substation or switch room shall be above the
highest flood level of the locality (over 100 year).
Generally the load centre would be somewhere between the
geometrical centre and the air conditioning plant room, as air
conditioning plant room would normally be the largest chunk of
load, if the building is air conditioned.

87. Substations with oil filled equipment will require great
consideration for the fire detection, protection and
suppression. Oil cooled transformers require a suitable
soak pit with gravity flow to contain the oil in the
event of the possibility of oil spillage from the transformer
on its failure.
Substations with oil filled equipment shall not be located in
any floor other than the ground floor or a semi-basement.
Such substations with high oil content may be housed in a
separate service building or a substation building, which is
not the part of a multi-storeyed building.

88. Oil filled transformers may be used only in substations
located in separate single or two storeyed service buildings
outside the main building structure and there shall at least
6 meter clear distance between the adjoining buildings and
substation such that fire tender is able to pass between the
two structures.

89. In case electric substation has to be located within the main
multi-storeyed building itself for unavoidable reasons, then
it should be located on the floor close to ground level, but
shall have direct access from the street for operation of the
equipments. The provision for installation and removal of
substation equipments may be provided from inside the
building.
Substations located within a multi-storeyed building shall
not have oil filled transformers, even if it is at the ground
level (see Part 4 ‘Fire and Life Safety’).

90. Substations with very little combustible material, such as
a Dry type transformer, with Vacuum (or SFJ HT
switchgear and ACB or MCCB for MV can be located in the
basement as well as upper floors in a building with high
load density in the upper floors.
(Some functional buildings such as hospitals, air traffic
control towers, computer centres are likely to have high
loading in a few upper floors and in such cases, it maybe
preferable to provide oil-free substations at upper levels.
This measure will decrease the current flow at various
points, thereby contributing to reduction of
vulnerability to fire).

91. If dry type transformer is used, it may be located
adjacent to medium voltage switchgear in the form of
unit type substation.
No separate room or fire barrier for the transformer is
required, in a substation with oil free equipment. In such
a case the room size will decrease. Layout of equipment
has to keep the requirement that any one piece of
equipment or sub-assembly can be taken out of service
and out of the installed location, while keeping the
remaining system in service.

92. The emergency power supply (such as Generating Sets)
should not be allowed to be installed above ground floor
or below first basement level of building. There shall be
provision of separate direct escape and entry into these
areas from outside so that in case of fire, electrical supplies
can be disconnected to avoid additional losses which may
be caused due to electrical supply, present at the time of
fire.

95. Aviation Light

96. Service Block