The document provides information on power distribution and electrical systems for metro stations. It discusses how 220kV or 66kV supply is received and stepped down through various panels to power essential systems. The main distribution board receives two 415V inputs that can be switched manually or automatically. Key panels discussed include the essential power panel, which powers critical loads through normal and backup sources, and the UPS panel. Fire detection, suppression and safety systems are also summarized.

1. E&M Lessons for
New Metros
.
Rajesh Agrawal
DGM/E&M
22nd July 2011

2. Distribution of Power
Supply
.
220kV or 66kV supply is received from
DISCOMS at RSS.
This supply is stepped down to 33kV for auxiliary
supply at stations.
Two cables run along the via-duct and at each
station to form ring main system.
In ASSs, the supply is further stepped down to
415V and fed to MDB of ESR.

3. Main Distribution Board
It receives two inputs I/C-I & I/C-II at 3 phase,
50Hz, 415V supply.
The inputs can be identified from the RYB
indicators available on the incoming feeders.
These two inputs feed two 3 phase bus bars of
MDB panel separated by bus coupler ACB through
ACB-I (for I/C-I ) & ACB-II ( For I/C-II ).

4. The generalized ratings of ACB`S for L-1
stations is- 415V 4P, 800A. With breaking
capacity –50kA
ACB-I (I/C-1), ACB-II (I/C-II) & B/C ACB are
interlocked electrically & mechanically. i.e.
During normal operation only two of the three
remain in ON condition. This avoids the
possibility of dead short circuiting of the two
incomers.

5. I/C-I I/C-II B/C Remark
ON OFF ON
I/C-1 has been given
priority & this condition is
generally observed.
OFF ON ON
I/C-2 has been given 2nd
priority.
ON ON OFF
Can be achieved
manually to service the
B/C ACB.
. In short :

6. Following outgoing supplies are taken
out from MDB
MLP-I
MLP-II
EsPP (Escalator Power Panel)
FPP (Fire Pump Panel)
WPP (Water Pump Panel)
Capacitor Bank-1,2,3,4,5 & 6
ACCP
S&T UPS
EPP-I (Essential Power Panel)
EPP-II

7. For switching the input supplies from I/C-I
to I/C-II automatically, following two
systems are generally used:
1) Contactor based source change over
system
2) ASTS (Auto Source Transfer System)

8. APFCR
(Auto Power Factor Correcting Relay)
Capacitor feeder shall be operated in
Auto/Manual mode.
 Auto Mode: APFC Relay senses the power factor
and release close/trip command to respective
capacitor feeders.
 Manual Mode: All Capacitor Feeder will operate
by pressing respective push buttons.
Auto mode, minimum 10% load should be
available.

9. Measurements
160/5A, CTs are provided for current
measurements, which feed Digital Ammeter &
current of different phases can be measured
with ASS ( Ammeter Selector Switch ).
230V/415V direct connect digital voltmeter
gives the different combination of Line &
Phase Voltages.
A digital integral meter is provided for the
measurement of other electrical parameters.

10. Essential Power Panel
All the essential loads are fed through this
panel.
This panel receives two inputs of normal
supply from MDB & the third from DG set.
There is interlocking between the three
incoming feeder
Priority has been given to I/C-I then I/C-II & in
absence of both I/C- I&II, the DG MCCB is
switched ON.

11. Capacity of DG set
CPCB norms
• Stack Height
• Sound proof enclosure
EIG approval
DG sets

12. The essential loads supplied by this panel
are:
1) S&T UPS
2) FPP
3) ELPP
4) ASS Battery Charger
5) EsLP- Essential Lighting Panel
6) MDB panel battery charger
7) UPS ( E & M )
8) MLP
Essential Power Panel

13. PROPERTY DEVELOPMENT
•Power supply
•Fire fighting regulation
•Differential Charges

14. The UPS (uninterrupted power supply )
Receives 3-phase, 415V, AC input from EPP,
it converts it to DC supply through converter.
The DC is fed for charging the on load battery bank for
inverter of UPS.
Inverter inverts the DC output into single phase 230V
AC supply which is then fed to UPS DB panel (UPS
Distribution board panel) for feeding:
EmLP - Emergency Lighting Panel &
FACP ( Fire alarm control panel )

15. LIGHTING SYSTEM
• In Line-1, 30% lights is on UPS, 30% on DG
supply and 40% on normal supply. Lights are
controlled through timer.
• In Line-3, 50% lights is on battery pack system
and all lights are on DG supply. The lights are
controlled through Dimmer System based on
lux level and calendar of the year.
•On / Off based on sun set / sun rise time.

16. AIR-CONDITIONING
• Technical Rooms
•SER,TER, S&T UPS, El. UPS
•Temperature Setting
•Comfort ACs
•SCR, TOM
•Temperature Setting
•Split A/c (location of ODU, drain)
•VRV System (location of ODU, drain)

17. Fire Detection & suppression System
Fire detection system & suppression system
are :-
•Fire detection system
•Fire Hydrant System
•Inergen system
•Fire trace tube
•Manual gas flooding system
•Fire extinguishers

18. Fire Detection System
Fire detection system are of two types :-
Addressable type :- In addressable type fire
detection the complete address comes on
detection panel of activated detector.
Conventional type :- In conventional type fire
system the indication of zone comes on
Detection panel and manually the source is to
be detected.

19. Fire Hydrant System
Fire hydrant system consists of
Pumps
Underground tank
Hose Box
Fire Brigade connection / water withdrawal
connection
Branch pipe & Nozzle
Hydrant Valves

20. SECURITY SYSTEM
Baggage X-ray machine
DFMD
HHMD

21. Pumps
Stand by Pump/Diesel pump :- Stand by
hydrant pump starts automatically when the
pressure drops below 3.5 kg/cm2 and after
quenching the fire it has to be stopped
manually.
Sprinkler Pump :- Sprinkler pump starts when
the pressure falls below 4 kg/cm2 after the
bulb of sprinkler shatters when the
surrounding air reaches at 80 deg. C.

22. Portable Fire Extinguishers
Following types of portable fire
extinguishers are being used :-
Water-CO2 type extinguisher
CO2 type extinguisher
Foam type fire extinguisher
Dry Chemical Powder

23. Water Supply
Bore well pumps
Tanks
Booster pumps
Automation System
Sump pumps

24. ELEVATOR

25. SPECIFICATION
• MONO SPACE MACHINE ROOM LESS
• LOAD – 8 Passenger – 630 Kgs
13 passenger – 1000 Kgs
• SPEED – 1 m/s
• POWER SUPPLY – 415 V, +/-10% 50Hz,+/- 3%
• MAX STARTS/HOUR –180
• LEVELLING ACCURACY-- +/-5mm
• MOTOR WATTAGE—5.75 KW
• MOTOR TYPE—SYNCHRONOUS ,GEAR LESS

26. PUSH BUTTONS
Braille push buttons for the
handicapped

27. ESCALATORS

28. SPECIFICATION
Step width – 1000 mm
Step band speed – 0.65 m/s or 0.5 m/s
Incline – 30 degrees
Rise -- 4.29 to 14.50 m
Balustrade -- Glass, Steel
Truss --Non oscillating and distortion
free jig-welded structure of
rectangular hollow steel profile.
Motor --IP55,dyanamic braking,

29. THANK YOU