ch 2.1.1single phasex

8/14/2019 Ch 2.1.1Single phasex

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6.1 Single Phase System

Description of 1 p

WiringSpecification

Exercise Assignment
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n Pengenalan

Pembahagian merupakanpembekal tenaga daripadasistem penghantaran kepadapencawang - utama danpencawang kecil kepadapelbagai pengguna.
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SISTEM KUASA PEMBAHAGIAN

12 kV 132kV

132kV

33kV

33kV11kV

11kV

415V/240V415V/240V

POWER

STATION

PE

TRANSMISSION

LINE

PEU/G & O/H

U/G & O/H

DISTRIBUTI

ON


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Stesan

Kuasa


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Single-phase electric powerrefers to the distributionof electric power using a system in which all thevoltages of the supply vary in unison.

Single-phase distribution is used when loads are mostlylighting and heating, with few large electric motors.


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The generation of AC electric power is commonly threephase, in which the waveforms of three supplyconductors are offset from one another by 120.

Standard frequencies of single-phase power systemsare either 50 or 60 Hz.


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A single-phase load may be powered from athree-phase distribution system either by

connection between a phase and neutral.In places using a 415 volt 3 phase system, thephase-to-neutral voltage is 240 volts, allowingsingle-phase lighting to be connected phase-to

ground and three-phase motors to be connectedto all three phases.


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Single-phase power distribution is widelyused especially in rural areas, where thecost of a three-phase distributionnetwork is high and motor loads aresmall and uncommon.

Picture


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Click to edit Master text stylesSecond level Third level Fourth level Fifth level


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Standard voltage for :-

a. Low Voltage Exceed low overvoltage but

not exceeding

i. 1000Vac @ 1500Vdc between conductor.

ii. 600Vac @ 900Vdc @ between conductor &

ground.b. Low voltage agreed at the national level -

i. 240V Single phase

ii. 415V 3 phase 4 wire.

HOME


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Distribution Board An assembly containing switching or

protective devices such as fuses, residualcurrent operated devices associated withone or more incoming circuit, togetherwith terminals for the neutral and

protective circuit conductors.

Functions :

1. Low voltage electric power distributionpoint.

2. Protection for output circuit.3. To cut supply efficiently if any

corruption


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SUPPLIER MAIN UNIT

Install outside the building at the wallsurface / premise entrance wall.

Easy to be check by the TNB - purposes

of the bill @ supply cutting .Contain of :

Cutting Unit

Meter kWj

Service Fuse

(Fius Perkhidmatan)

Neutral connector

(Penyambung Neutral)HOME


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Connected to the main supply inlet

To the phase conductor.

To protect user main circuit.

To makesure the current across notexceed the max. limit.

Fuse will blow / open cct ifovercurrent occurred.

Using catridge type of fuse.

SERVICE FUSE AND

NEUTRAL CONNECTOR

Picture

HOME


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Meter kWj

To measure amount of energy/power that have been used by the

consumer in a certain time ofperiod.

Fixed with cutter unit at theinstallation main board.

HOME


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Distribution Box

Use to distribute main power supply tofinal cct @ to sub distribution fuse box.

Contain of life, neutral & earth supply.Each connection have separate fuse or

cct breaker.

The box structure is made of pvk/plastic

& metal.


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The present fuse box distribution fuse boxminiature type that made with plastic material @

long lasting pvk material. It is also attach withtransparent cover that allowed the user toobserve the fuse arrangement / cct breaker.

The main fuse , earth leakage cct breaker &

fuse / cct breaker (CB) is assemble in miniatureform.

Every parts is assemble / arrange in one line form.

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a n omponen


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a n omponen1. Miniature main Switch (Onload switch

fuse)

Power inlet source is from down side of the main switch.

Power outlet source is from up side of the main switch.

It is in cartridge type. Rate should same with the external fuse

Able to be disassemble via the transparent cover.

Assembly method - by clipping the main switch to the bar

area.

Click to edit Master text styles

Second level Third level Fourth level Fifth level

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2 Earth Leakage Cct Breaker


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2. Earth Leakage Cct Breaker(ELCB)

ELCB is a device that protect consumer from electric shock.This gadget must be fitted in every alectric assembly.

If the leakage current is higher than the max spec limit,the switch will be automatically OFF for protection.

Push the T small switch to check the RCCB reliability.For maintenance, this switch need to be check everymonth to make sure it is in good condition.



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ELCB is a device with two earthterminals used to directly detect currents

leaking to earth from an installation andcut the power.

They were mainly used on TT earthing

systems.

By having the assumption of the

presence of current in the earth line, itmeans there is any leaking current fromthe main incoming live cable, thus thepower has to be cut off to ensure thesafet .


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State of ELCB when it cuts the poweris

called tripped. Every time the ELCBtripped,

we can reset it back (connect back

the powerline) by resetting the trip button.


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Nowadays, they have been almost

totally replaced by Residual-currentdevice (RCD) due to a number ofproblems:

a. They cannot detect earth faultsthat do not go through the earthing

system.


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b. They do not allow a system to be easilysplit

into multiple sections withindependent fault

protection, due to the fact thatearthing

systems are usually bonded tothings like

pipework.

c. They may be tripped by externalvoltages on

something connected to the

earthing system such as metal pipes, a TN-S earth or a TN-C-S combined neutralHOME


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3. Miniature Cct Breaker (MCB)

Overcurrent The value should be higher than the current capacity in thecct.

Overcurrent effect the insulator/ conductor will be damage & can cause

fire.Rated current not more than 100A.

Thermal @ thermal magnetic operation


Picture

1 Actuator lever used to


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1. Actuator lever - used tomanually trip & reset the ccttbreaker. Also indicates the status(On @ Off/tripped).2. Actuator mechanism - forcesthe contacts together @ apart.3. Contacts - Allow current to flowwhen touching and break the flow

of current when moved apart.4. Terminals5. Bimetallic strip6. Calibration screw - allows the

manufacturer to precisely adjustthe trip current of the device afterassembly.7. Solenoid

8. Arc divider / extinguisher


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Use as a protector that is in 2 mode :-

a. Over current protector Bi-metal method

b. Failure/ Damage protector Solenoid method

If the S/C or O/C occur, MCB will automatically OFF.MCB can be set to ON by push the ON button.

Several type of current for MCB can be use at the finalwiring cct depand to the appropriate condition such as : -Lighting cct 6A

- Power cct 16A

- Power cct 20A

1 MCB only can be connected to one small cct.

Picture

HOME


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Normalpositionbreaker ONBi Metal stripbending, about totripContacts

opening, arcformingArc isextinguished, hot gasexist

Contactsfully open


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Miniature distribution box assembly


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The picture shows how the main fuse, RCCB and MCBassemble together in the miniature distribution box.

The box size is categorized by the WAY term. i.e. 10way, 12 way, 15 way, & etc.

The higher the no, the bigger the size will be.

This means the quantity of MCB can be add dependto the box size.

Size available in market :

- 2, 4, 6, 8, 10, 12, 15, 18, 21 & 24.

Picture


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Picture shown the cct diagram of unit pepotong( service fuse, neutral connector &

power meter ) with the user distribution box

( main switch, ELCB & MCB )


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How to check the fuse box?

1. Fuse give protection by cutting the flow ofcurrent in the cct if O/C or fault occur.

2. When the S/C @ O/L occur, fuse in the cctwill open the cct.

3. To get the supply back, we need to change

the fuse.4. Turn off @ dissamble all the equipment that

connected to the cct.

5. Change to the new fuse that is same specwith the broken fuse. i.e. 15 A change with

15 A.

6. Dont touch the fuse metal area when take

off @ install the fuse.


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7. Switch OFF the main swith if the fuse boxattached to the main switch.

8. ON the main switch.9. If the fuse broken even no equipment

connected yet to the cct, maybe there isserious fault happened the wiring cct. Call the

authorized @ accredited person.10. If the fuse broken after the equipment

connected to the cct, maybe there is S/C occurin the equipment cct.

fi i i


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Definition1. Consumer circuit Cct which is installed

at consumer unit until the final

equipment that used by consumer.

1. Radial circuit for 13A outlet socket Cct

which installed at consumer unit of 16AMCB and end at 2 outlet socket 13A.

1. Ring circuit for 13A outlet socket - 13A

outlet socket installed not more than 6unit and return wiring the same point atconsumer unit. Wiring is completelyloop.


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Information label at the switch gear switching devices.

Kadaran Vdc dan Vac

Kadaran arus

Kadaran arus litar pintas

No siri

Data breaking capacity

No Model


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ch 2.1.1single phasex

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