The document provides information on various electrical services including definitions, types of current, single and three phase power supply systems, electricity generation, earthing, lightning protection, and wiring accessories. It defines key electrical terms and describes: - Alternating and direct current, their characteristics and examples of use - Single and three phase power supply systems including their components, voltages, applications and advantages - The process of electricity generation, transmission, and distribution to end users - Methods of earthing buildings for safety and reducing earth resistance - Lightning protection systems used to protect structures from lightning strikes - Common wiring accessories like switches, sockets, plugs, and their uses in electrical installations

1. ELECTRICAL SERVICES
SUBMITTED BY:-
RIDDHESH RAJENDRA VARIK
15SA31 T.Y.B.ARCH
ST.WILFREDS INSTITUTE OF ARCHITECTURE

2. INDEX
SR.NO TITLE PAGE NO.
1 DEFINITIONS 1
2 ALTERNATING CURRENT 2
3 DIRECT CURRENT 3
4 SINGLE PHASE POWER SUPPLY 4
5 THREE PHASE POWER SUPPLY 6
6 GENERATION OF ELECTRICITY 8
7 EARTHING 9
8 LIGHTNING PROTECTION 12
9 WIRING ACCESORIES 14

3. CIRCUIT:
CIRCULAR PATH WHICH ALWAYS GETS ELECTRIC FLOW.
VOLTAGE:
VOLTAGE IS THE DIFFERENCE IN CHARGES BETWEEN TWO POINTS OR IT IS THE AMOUNT OF POTENTIAL ENERGY
BETWEEN TWO POINTS OF A CIRCUIT.
AMPERE:
AMPERE IS THE UNIT OF CURRENT OR SAFE FLOW OF AN ELECTRIC CURRENT.
OHM:
OHM IS THE UNIT OF RESISTANCE.
WATTS:
WATT IS THE UNIT OF POWER.IT IS DENOTED AS W.
WATT = AMPERE X VOLT
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4. ALTERNATING CURRENT
WHEN THE CURRENT VARIES IN THE DIRECTION AND
MANGNITUDE PERIODICALLY IT IS CALLED AS DIRECT
CURRENT.
IT IS THE MOVEMENT OF ELECTRIC CHARGES
PERIODICALLY IN REVERSE DIRECTION.
EACH COMPLETE CYCLE CONSISTS OF TWO HALF
CYCLES IN OPPOSITE DIRECTION I.E. ONE IN POSITIVE
AND OTHER IN NEGATIVE.
AMPLITUDE: MAIN VALUE OF POSITIVE AND NEGATIVE
HALF OF A.C WAVE.
PERIODIC TIME: TIME TAKEN BY A.C TO COMPLETE
ONE CYCLE I.E. 360 ROTATION.
FREQUENCY: THE NUMBER OF CYCLES COMPLETED
IN ONE SECOND.IT IS DENOTED BY ‘F’.
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5. DIRECT CURRENT
IN AN ELECTRIC CIRCUIT DIRECT CURRENT FLOWS CONTINOUSLY IN ONE DIRECTION ONLY.
APPLIED VOLTAGE AND CIRCUIT RESISTANCE ARE KEPT CONSTANT.
MAGNITUTE OF CURRENT FLOWING THROUGH THE CIRCUIT REMAINS CONSTANT.
EG:- BATTERY PROVIDES 1.5V.
DIRECT CURRENT IS UNIDIRECTIONAL
DIRECT CURRENT IS PROVIDED BY SOURCES SUCH AS BATTERIES, THEROCOUPLES, SOLAR CELLS, ETC.
ELECTRICAL CHARGES FLOWS IN CONSTANT DIRECTION.
EXAMPLES OF DIRECT CURRENT INCLUDES CELL PHONES, FLAT SCREEN T.V.’S, FLASHLIGHTS, ELECTRICAL
VEHICLES.
DIRECT CURRENT LOOKS LIKE A FLAT LINE WHEREAS ALTERNATING CURRENT LOOKS LIKE A WAVE.
INDIRECT CURRENT, BATTERIES HAVE A POSITIVE AND NEGATIVE TERMINAL AND ELECTRICAL CHARGES MOVE
IN ONLY ONE DIRECTION FOR A STEADY RATE.
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6. SINGLE PHASE POWER SUPPLY SYSTEM
 IT IS A 2 WIRE (LIVE WIRE AND NEUTRAL WIRE) SYSTEM WITH VOLTAGE RANGING FROM
(220V TO 240V)
STANDARD VOLTAGE SINGLE PHASE POWER SUPPLY SYSTEM IS 230V
POWER FLOWS FROM POWER CONDUCTOR THROUGH THE LOAD TO NEUTRAL
CONDUCTOR.
SINGLE PHASE DISTRIBUTION IS USED WHEN LOADS ARE MOSTLY LIGHTING AND HEATING.
EG:- USED FOR HOUSES AND SIMILAR PROPERTIES.
SINGLE PHASE POWER SUPPLY HAS CONDUCTOR WHICH HAVE A SINE WAVE TAT IS 180
APART.
SINGLE PHASE POWER SUPPLY SYSTEM CAN HANDLE UPTO 7.5 KW I.E. 7500 VOLTS.
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7. 5

8. THREE PHASE (4 WIRE) POWER
SUPPLY SYSTEM :-
ITS VOLTAGE RANGES FROM 440V TO 400V
4 CORE CABLES WITH 3 PHASE WIRE AND ONE NEUTRAL
3 PHASE ELECTRICAL POWER SYSTEM HAVE AT LEAST 3 CONDUCTORS
CARRYING ALTERNATING CURRENT.
230V BETWEEN THE NEUTRAL AND ANY ONE OF THE PHASE AND 415V ACROSS
ANY TWO PHASES.
3 PHASE CONNECTIONS CAN HANDLE HEAVY LOAD ABOVE 7.5KW (7500
VOLTS)
3 PHASE POWER SUPPLY SYSTEM IS MORE EFFICIENT AND USED IN
INDUSTRIAL PURPOSE.
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9. ADVANTAGES :-
INSTALLATION AND MAINTENANCE COST ARE
COMPARATIVELY LESS.
3 PHASE SYSTEM USES LESS CONDUCTOR,
MATERIAL.
3 PHASE POWER LINES CARRIES MORE
POWER.
3 PHASE POWER SUPPLY SYSTEM REQUIRES
FEWER CIRCUIT BREAKERS.
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10. GENERATION OF ELECTRICITY
EG. THERMAL POWER HYDRO POWER
ELECTRICITY FLOWS THROUGH A METAL CONDUCTOR TO A SWITCH YARD
WHERE TRANSFORMER STEPS UP VOLTAGE FOR TRANSMISSION.
TRANSMISSION LINES CAN EFFICIENTLY CARRY HIGH VOLTAGE ELECTRICITY
OVER LONG DISTANCES TO SUBSTATIONS.
AT SUBSTATIONS, ELECTRICITY IS STEPPED DOWN SO IT CAN TRAVEL OVER
SMALLER DISTRIBUTION LINE TO HOMES, BUS BARS.
DISTRIBUTION LINES CARRY ELECTRICITY TO NEIGHBOURHOOD
TRANSFORMER.
AN ELECTRIC POLE TRANSFORMER REDUCES THE VOLTAGE LEVEL THAT CAN
BE USED IN HOMES OR BUSINESS/COMMERCIAL SPACES.
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13. EARTHING :-
AN IMMEDIATE DISCHARGE OF ELECTRICAL ENERGY TAKES PLACE TO THE EARTH
WITHOUT ANY DANGER.
EARTHING MEANS CONNECTING THE NEUTRAL POINTS TO THE SUPPLY.
EARTHING HELPS BOTH OF THE EQUIPMENT TO ZERO POTENTIAL.
PURPOSE :
-TO AVOID ELECTRICAL SPARK
TO AVOID RISK OF FIRE DUE TO LEAKAGE OF CURRENT THROUGH UNWANTED PATH.
EARTHING METHODS :-
EARTHING WIRE CONNECTED FROM BUILDING TO THE EARTH ELECTRODES WHICH
IMBEDDED ON THE EARTH.
TWO TYPES OF EARTH ELECTRODES :-
PIPE ELECTRODES
PLATE ELECTRODES
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14. PIPE ELECTRODES :-
COMMON AND BEST METHOD.
DIAMETER OF PIPE SHOULD BE SUFFICIENT TO THE EARTH
THE FAULT CURRENT.
G.I. PIPE SERVES AS ELECTRODES.
FOR ORDINARY SOIL, MINIMUM 28MM DIA PIPE AND 2M LONG.
FOR DRY SOIL, LENGTH OF PIPE SHOULD BE 3M.
PIPE SHOULD BE PLACED IN PERMANENTLY WET GROUND.
CHARCOAL AND SALT ARE FILLED IN THE PIT IN ALTERNATE
LAYERS TO MAINTAIN DAMPNESS AND MOISTURE AROUND THE
PIPE. THE LAYER SHOULD BE OF MINIMUM 6 INCHES.
THE PIPE PLACED HAS 12MM DIA TO SPREAD WATER TO THE
CHARCOAL LAYER.
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15. PLATE EARTHING :-
EARTHING IS DONE BY EMBEDDING G.I. OR COPPER PLATE IN THE EARTH
SUFFICIENTLY DEEP.
THE SIZE OF THE PLATE USED SHOULD NOT BE LESS THAN
600X600X6MM IN CASE OF G.I. PLATE.
THE SPACE AROUND THE PLATE IS FILLED WITH LAYERS OF CHARCOAL
AND SALT FOR MINIMUM THICKNESS OF 150MM
THE PLATE IS CONNECTED TO G.I. PIPE FOR CARRYING G.I. EARTH WIRE
FOR CONNECTION TO EARTH ELECTRODE.
PIPE SHOULD BE CONNECTED WITH FUNNEL FOR CARRYING WATER TO
MAINTAIN DAMPNESS AND MOISTURE TO REDUCE EARTH RESISTANCE.
G.I. PLATE EARTH ELECTRODES CAN BE USED FOR INDUSTRIAL LOAD
UPTO 30 HP.
INDUSTRIAL LOAD UPTO ABOVE 30HP, COPPER PLATE EARTH ELECTRODE
ARE RECOMMENDED.
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16. LIGHTING PROTECTION OF A BUILDING
SYSTEM :-
LIGHTING IS THE SUDDEN DISCHARGE OF ELECTRIC CHARGE FOR SHORT DURATION WITH
HIGH VOLTAGE.
LIGHTNING PROTECTION SYSTEM INVOLVES
A) PROCEDURE TO PREVENT RISK OF LIGHTNING STRIKES
B) PROTECTION OF STRUCTURE AGAINST DIRECT LIGHTNING STROKES.
C) PROTECTION OF ELECTRICAL INSTALLATION.
D) TO PREVENT DISTURBING ENERGY FROM REACHING SENSITIVE EQUIPMENTS.
E) CAPTURE THE LIGHTNING CURRENT AND CHANNEL IT TO EARTH VIA DIRECT PATH
TWO TYPES OF PROTECTION SYSTEMS ARE USED :-
ELIMINATE
LIMIT OVER VOLTAGE.
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17. THREE TYPES OF LIGHTNING PROTECTION SYSTEMS ARE USED :-
SIMPLE LIGHTNING ROD SYSTEM.
LIGHTING ROD WITH TAUT WIRE SYSTEM.
LIGHTNING CONDUCTOR WITH MESHED CAGE. (FARADAY CAGE)
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18. WIRING ACCESSORIES
WIRING ACCESSORIES ARE BEING USED IN
DOMESTIC AS WELL AS COMMERCIAL WIRING.
SOME IMPORTANT ELECTRICAL ACCESSORIES
SWITCH : SWITCH IS USED TO MAKE OR
BREAK THE ELECTRIC CIRCUIT OR IT IS USED
TO SWITCH ‘’ON OR OFF’’ THE ELECTRIC
SUPPLY.
SURFACE SWITCH : SWITCHES ARE MOUNTED
ON WOODEN BOARD , FIXED OVER THE
SURFACE OF THE WALL.
SOCKET : AN ELECTRICAL DEVICE RECEIVING
A PLUG OR LIGHT BULB TO MAKE A
CONNECTION.
.
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19. WIRING ACCESSORIES
LAMP HOLDER : A LAMP HOLDER IS
USED TO HOLD THE LAMP ; AND
CONNECT IT ELECTRICALLY TO
SUPPLY TERMINALS , REQUIRED FOR
LIGHTING PURPOSES.
PLUG : THE PLUGS ARE ALSO
HAVING MOULDED THREE PINS OF
BRASS OR ANY ELECTRICALLY
CONDUCTING MATERIAL. THESE ARE
ALSO MADE OF 5AMP AND 15AMP
RATING. THESE ARE USED FOR
TAKING POWER FROM SOCKET.
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20. WIRING ACCESSORIES
MAIN SWITCH : THIS SWITCH IS USED TO
SWITCH “ON OR OFF” THE MAIN SUPPLY .
THESE SWITCHES ARE USED TO CONTROL
THE WHOLE SUPPLY FOR A HOUSE ,
OFFICE AND MACHINE . IN SINGLE PHASE
CIRCUIT I.C.D.P MAIN SWITCHES ARE
USED, WHEREAS IN THREE PHASE
CIRCUITS I.C.T.P. MAIN SWITCHES ARE
USED TO CONTROL THE SUPPLY.
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21. WIRING ACCESSORIES
 I.C.D.P. SWITCH: IRON CLAD DOUBLE POLE MAIN
SWITCH IS USED IN SINGLE-PHASE SUPPLY CIRCUITS.
THESE ARE AVAILABLE IN 15 AMP, 30 AMP, 60 AMPS AND
100 AMPERES CURRENT RATING. IN THESE SWITCHES,
EITHER TWO NUMBERS OF FUSE LINKS ARE PROVIDED
OR A FUSE LINK AND A NEUTRAL LINK IS PROVIDED.
 I.C.T.P SWITCH: IRON CLAD TRIPLE POLE MAIN
SWITCHES ARE USED TO CONTROL THE THREE PHASE
SUPPLY CIRCUIT. THESE ARE AVAILABLE IN 15 AMP, 30
AMP, 60 AMP,100 AMP, 150 AMP AND 250 AMPS CURRENT
RATING. GENERALLY THESE SWITCHES ARE ALSO
KNOWN AS 3 PHASE 4 WIRES MAIN SWITCHES.
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22. WIRING ACCESSORIES
FUSE:IT IS THE MOST COMMON AND IMPORTANT TYPE OF
SAFETY DEVICE USED FOR DOMESTIC AND COMMERCIAL
INSTALLATIONS. THESE FUSES ARE OF KIT-KAT TYPE AND
ARE ALSO KNOWN AS CUT-OUT. THESE CUT-OUTS ARE
MADE OF PORCELAIN IN CURRENT RATING OF 15 TO 300
AMPERES. THE MATERIAL USED AS A FUSE WIRE IS TIN,
LEAD, SILVER, ANTIMONY, COPPER AND ALUMINIUM ETC.
COPPER OR LEAD, TIN ALLOY IS MOSTLY USED IN
ORDINARY FUSE WIRE.
MINIATURE CIRCUIT BREAKER (M.C.B.):A MINIATURE
CIRCUIT BREAKER IS AN ELECTRO-MECHANICAL SAFETY
DEVICE WHICH OPERATE AND DISCONNECT THE CIRCUIT
SUPPLY, WHEN THE CURRENT DRAWN FROM THE CIRCUIT
INCREASES TO A PRE-DETERMINED VALUE. THESE ARE
USED IN LIEU OF FUSES AND CAN BE FITTED IN
CONSUMER’S DISTRIBUTION BOARD.
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