Domestic Electricity

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Domestic Electricity


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Service Mains

A small cable which connects distributers line to home supply wire is known

as service mains.


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Distribution Boards

A distribution board consist of a suitable enclosurecontaining

- Fuses and/or circuit breakers and other- protective devices- Switching devices- Control devices.- Busbars

This enclosure may be either of metal clad or all

insulated type of construction.


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Protection/ Location of Distribution Boards

Shall be protected against dust, moisture, corrosive or polluting

substances, excessive temperatures, impact, vibration and other

mechanical stresses.

Shall be readily accessible and not located over cooking or

heating appliances, in bathrooms, washrooms or WCs, in storage

or airing cupboards, under staircases or where it might be coveredby garments.

Shall not be located above or below, or within 400mm horizontally

from a gas meter or a gas appliance in the same space.

Shall be protected against damage arising from a fault in other

services achieved by the use of barriers or by separation.


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Introduction of wiring.

Types of wiring according to the Uses.

1. Domestic Wiring.

2. Commercial Wiring.

3. Industrial Wiring.

WIRING


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Factors Affecting choice of wiring

Safety

Duration

Appearance

Accessibility

Maintenance

Cost


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Types of Wiring

1. Cleat Wiring2. Casing Capping wiring

(a) Wood Casing capping Wiring(b) PVC Casing Capping Wiring.

3. Batten Wiring(a) PVC Batten wiring.

(b) TRS/CTS Wiring. Lead Shedh Wiring.

4. Conduit Wiring

(a) Surface conduit wiring

Metal Conduit Wiring

PVC conduit wiring

(b) Cunceald Conduit Wiring

Metal Conduit Wiring.

PVC Conduit wiring.


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Introduction

The types of wiring to be adopted is dependent on

various factors : durability, safety, appearance, cost,

consumers budget etc.

Cleat wiring

This System uses insulated Cables sub protected

in porcelain cleats.

CLEAT WIRING


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Temporary installations

The cleats are made in pairs having bottom and top halves.

The bottom half is grooved to receive the wire and the top half isfor cable grip.

Initially the bottom and top cleats are fixed on the wall looselyaccording to the layout. Then the cable is drawn, tensioned and thecleats are tightened by the screw.

Cleats are of three types, having one, two or three grooves, so as toreceive one, two or three wires.

Cleat wiring is one of the cheapest wiring considering the initialcost and labor, and is most suitable for temporary wiring.

This wiring can be quickly installed, easily inspected and altered.When not required, this wiring could be dismantled withoutdamage to the cables, cleats and accessories


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Cleats shall be fixed at distances not more than 60 cm apart

and at regular intervals.

porcelain or plastic cleats are used.

Fixing of cleats

In ordinary cases, cleats shall be attached to wooden plugs

fixed to the walls


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Introduction

This system of wiring is suitable for low voltage installation

In this wiring, cables like vulcanized rubber, insulated cables or plastic

insulated cables are used and carried within the wood casing enclosures.

CASING CAPPING WIRING


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Material and pattern of casing All casing shall be of first class, seasoned teak wood or any other approved

hardwood free from knots, shakes, saps or other defects, with all the sides

planed to a smooth finish, and all sides well varnished, both inside and outside with pure shellac varnish. The casing shall have a grooved body with a

beaded or plain- molded cover as desired.

Dimensions of casing.

The size of casing and capping to be used for various sizes of 250 volts

grade insulated cables in a groove shall be in accordance with thosespecified in table 1.

Bunching of circuits.

Attachment of casing to wall and ceiling.

Attachment of capping.

Passing over the floors.

Joints in casing and capping.


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Introduction

In general, a conduit is defined as a tube or channel.

Tubular conduit is the most commonly used

material in electrical installations. When cables aredrawn through the conduit and terminated at the

outlet or switch points, the system of wiring is

called conduit wiring.

CONDUIT WIRING


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Types of conduits.

There are four types of conduits used for wiring.

1.Rigid steel conduit

2.Rigid non-metallic conduit

3.Flexible steel conduit

4.Flexible non metallic conduit.


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Study of electricity bill

C t f l t i it bill


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Components of electricity bill

Customer's electric bill consists of the following components for Residential/

Domestic usage:

Energy Charges Depends on Tariff

Fixed Charges A monthly fixed charge for the installed energy meter

Fuel

Adjustment

Charges

(FAC)

The prevailing tariff for energy is based on an average cost

of fuel consumed for electrical energy generation.

The actual cost of fuel may vary from this cost.

To account for this difference in price, a "Fuel Adjustment

Charges" (FAC) is levied.

Electricity

Duty

State Government charge

Tax on Sale of

Electricity

Tax on sale of electricity is applied on all units sold in

accordance with State Government

Delayed

Payment

Charges

In case electricity bills are not paid within the due date

mention on the bill, delayed payment charges on the total

electricity bill (including Taxes & Duties) shall be applied on

the bill amount.

Prompt payment

discount

A payment discount on the monthly bill (Excluding taxes &

Duties) shall be available to the consumers if the bills are paidwithin time limit.

A l f h k i i i b l


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An example of how to work out your consumption is given below :

Sr No. Description Wattage Nos.

Average usage

in hours per

day

Energy Consumption per

month in units (kWh)

1Tube Light

(Ordinary choke)40 5 6

40 x 5 x 6 x30 = 36

1000

2 Fan 40 4 14

40 x 4 x 14 x

30 = 67

1000

3 Electric Iron 750 1

750 x 1 x x

30 = 11

1000

4 Geyser 3000 1

3000 x 1 x

x 30 = 45

1000

5 Colour T.V. 80 1 8

80 x 1 x 8 x

30 = 19

1000

Total 187 units


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SWITCH


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Earth Leakage Circuit Breaker


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An Earth Leakage Circuit Breaker (ELCB) is a safety device used in

electrical installations with high earth impedance to prevent shock. It

detects small stray voltages on the metal enclosures of electrical equipment,

and interrupts the circuit if a dangerous voltage is detected. Once widely

used, more recent installations instead use residual current circuit breakerswhich instead detect leakage current directly.

Operation

An ELCB is a specialised type of latching relay that has a building's

incoming mains power connected through its switching contacts so thatthe ELCB disconnects the power in an earth leakage (unsafe) condition.

The ELCB detects fault currents from live to the earth (ground) wire

within the installation it protects. If sufficient voltage appears across the

ELCB's sense coil, it will switch off the power, and remain off untilmanually reset. A voltage-sensing ELCB does not sense fault currents

from live to any other earthed body.

R l
http://en.wikipedia.org/wiki/Earthing_systemhttp://en.wikipedia.org/wiki/Residual_current_circuit_breakerhttp://en.wikipedia.org/wiki/Relayhttp://en.wikipedia.org/wiki/Relayhttp://en.wikipedia.org/wiki/Fault_currenthttp://en.wikipedia.org/wiki/Voltagehttp://en.wikipedia.org/wiki/Electric_powerhttp://en.wikipedia.org/wiki/Electric_powerhttp://en.wikipedia.org/wiki/Voltagehttp://en.wikipedia.org/wiki/Fault_currenthttp://en.wikipedia.org/wiki/Fault_currenthttp://en.wikipedia.org/wiki/Fault_currenthttp://en.wikipedia.org/wiki/Relayhttp://en.wikipedia.org/wiki/Relayhttp://en.wikipedia.org/wiki/Relayhttp://en.wikipedia.org/wiki/Relayhttp://en.wikipedia.org/wiki/Residual_current_circuit_breakerhttp://en.wikipedia.org/wiki/Residual_current_circuit_breakerhttp://en.wikipedia.org/wiki/Residual_current_circuit_breakerhttp://en.wikipedia.org/wiki/Residual_current_circuit_breakerhttp://en.wikipedia.org/wiki/Residual_current_circuit_breakerhttp://en.wikipedia.org/wiki/Residual_current_circuit_breakerhttp://en.wikipedia.org/wiki/Residual_current_circuit_breakerhttp://en.wikipedia.org/wiki/Earthing_systemhttp://en.wikipedia.org/wiki/Earthing_systemhttp://en.wikipedia.org/wiki/Earthing_system


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What is a relay ?A relay is usually an electromechanical device that is

actuated by an electrical current.

The current flowing in one circuit causes the opening orclosing of another circuit.

Relays are like remote control switches and are used inmany applications because of their relative simplicity, long

life, and proven high reliability. Relays are used in a wide variety of applications throughout

industry, such as in telephone exchanges, digital computersand automation systems.

Highly sophisticated relays are utilized to protect electric

power systems against trouble and power blackouts as wellas to regulate and control the generation and distributionof power. In the home, relays are used in refrigerators,washing machines and dishwashers, and heating and air-conditioning controls.

Relay


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Electro mechanical Relay

S lid St t R l


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Solid State Relay

Domestic Electricity

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