Megger- Boletín #1 sobre interruptores de potencia- Funcionamiento-Tipos

7/24/2019 Megger- Boletn #1 sobre interruptores de potencia- Funcionamiento-Tipos

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TSGApplication Bulletin 006 1 of 7 25/03/2010

Application Bulletin (006)

Circui t Breakers Part 1

From: Simanand Gandhi Jeyaraj, Applications Engineer, Technical Support - Dover

Introduction: The moment the term Circuit breaker or its testing comes up for discussion, eachengineer / technician / sales person may assume different variants in their mind because of the

generic name circuit breaker for around 20 different types. At times classifications are alsooverlapped and cross referred. Hence this application note is to focus on the type of circuitbreakers available in the market and also to brief how a typical high voltage circuit breakeroperates during close and trip function.Being a part-I application note, forthcoming parts will discuss on the topics like circuit breakerparts and its functionalities, Tests to be done on site, Testers and its functionalities, advancedtesting and analysing tools, etc.

What is a circuit breaker?

Where and why it is used?

What are the types available?

How does a high voltage circuit breaker work?

**************************************************************************************************************

What is a circuit breaker?

Standard IEC 265-1:1983 specifies, a circuit breaker is a mechanical device of connection,

capable of establish, withstand and break the current under the normal operation of the circuit

and occasionally, under specific overload in-service conditions, as well as endure specific

abnormal circuit currents (e. g. short circuit currents) during a given time (generally fractions ofsecond).

Where and why it is used?

Circuit breakers are similar to fuse in any LV electrical circuit. Circuit breakers are used in

electrical circuits where protection is necessary from over load and short circuit by breaking the

circuit and protecting the equipments like feeders, generators, motors, transformers and any

electrical apparatus connected.


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TSG Applications Bulletin 008 2 OF 7

What are the types available?

CIRCUIT

BREAKER

CB WITHOUT INBUILT-SELF TRIPPING

MECHANISM / RELAY

CB WITH INBUILT -SELF TRIPPING

MECHANISM /

RELAY

MCB MCCB LOW ORMEDIUM VOLTAGE CB

WITH

INBUILT TRIP SETTING

By

Phase

By

Design

By

Installationtype

By

VoltageClass

By External

Design

By number of

Interrupters /Breaks per

phase

1- Phase3 -Phase

Gasinsulated

Open ty peIndoor

Outdoor

FixedDraw out

LV,MV

HVEHV and

UHV

Live tank

Dead t ank

1 break

2 breaks2 breaks with PIR4 break .

Up to 12 breaks

CIRCUIT

BREAKER

By arc

extinctionmedium

By type of

operatingmechanism

By drive on

three phase

Oil

Air blastMagnetic blastVacuumGas

Spring-operated

Electro magnetHydraulic

Pneumatic

Motor-operated

Common

Separate


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CB TYPES EXAMPLES

Inter rupter(Vacuum or Gas)

Oper ating Mechanism withTr ip and Cl ose coil s

Fig-4: Typical d raw out type Medium Voltage breaker (withVacuum or SF6 interrupters)

Fig-3: LV or MV CB with inbuilt

Trip mechanism / relay

Fig-1: Typical MCB 1 phase

Fig-2: MCCB 3 phase


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Interr upter

Operating Mechanism withTrip and Cl ose coil s

Fig-6: Typical Dead tank circuit breaker

Fig-5: Typical l ive tank Circuit breaker

Inter rupter

(Vacuum or Gasor Oil f il l ed)

Suppor tinginsul ator

Oper ating Mechanism withTr ip and Cl ose coils


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2 Br eak perphase

Fig-8: 2 break per phase Three phase CB

Fig-7: 1 break per phase Three phase CB

1 Br eak perphase


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Fig-10: Separate drive for three phases

3 separate operatingmechanisms f or 3 phases hence

3 set of tr ip and cl ose coil s

Fig-9: Common drive for three phases

1 oper ating mechanismfor 3 phases hence 1 set

of tr ip and cl ose coil


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How does a typical high voltage circuit breaker operate?

This topic explains the operation of the circuit breakerwithout inbuilt-self trippingmechanism / relay. The sequences of operation of a circuit breaker system while closing under

normal condition and tripping on occurrence of a fault are as follows:

CLOSE FUNCTION

TRIP FUNCTION

Questions may be directed to Simanand Gandhi Jeyaraj at [email protected]

3) I w ill provide theload current value

continuously to therelay once CB is

closed

2) I will close andinform back through

Aux contact

1) I wi ll issue theclose commandif I was switched

ON

1) A fault

hasoccurred

2) I haveinformed

the relay.

3) I havecommanded

the CB to trip

4) I will tr ip and informback through Auxcontact
mailto:simanand.gandhi:@megger.commailto:simanand.gandhi:@megger.com

Megger- Boletín #1 sobre interruptores de potencia- Funcionamiento-Tipos

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