Circuit Breakers and their mechanism

1. Circuit BreakerCircuit Breaker
MarketElectrical.com

2. What is a circuit breakerWhat is a circuit breaker??
 AA circuit breakercircuit breaker is an automatically-operatedis an automatically-operated
electrical switch designed to protect an electricalelectrical switch designed to protect an electrical
circuit from damage caused by overload or shortcircuit from damage caused by overload or short
circuit. Its basic function is to detect a faultcircuit. Its basic function is to detect a fault
condition and, by interrupting continuity, tocondition and, by interrupting continuity, to
immediately discontinue electrical flow.immediately discontinue electrical flow.

3. Basic difference between fuse nBasic difference between fuse n
circuit breaker ?circuit breaker ?
 . Unlike a fuse, which operates once and then. Unlike a fuse, which operates once and then
has to be replaced, a circuit breaker can be resethas to be replaced, a circuit breaker can be reset
(either manually or automatically) to resume(either manually or automatically) to resume
normal operation.normal operation.

4. Detail picture of circuit breakerDetail picture of circuit breaker

5. Parts of Circuit breakerParts of Circuit breaker
1. Actuator lever - used to manually trip and reset the circuit
breaker. Also indicates the status of the circuit breaker (On
or Off/tripped). Most breakers are designed so they can still
trip even if the lever is held or locked in the "on" position.
This is sometimes referred to as "free trip" or "positive trip"
operation.
2. Actuator mechanism - forces the contacts together or apart.
3. Contacts - Allow current when touching and break the
current when moved apart.
4. Terminals
5. Bimetallic strip
6. Calibration screw - allows the manufacturer to precisely
adjust the trip current of the device after assembly.
7. Solenoid
8. Arc divider/extinguisher
Parts of circuit breaker:Parts of circuit breaker:

6. Manufacturers of CBManufacturers of CB
 The main competitors in this field areThe main competitors in this field are
 SQ D / SchneiderSQ D / Schneider
 SiemensSiemens
 GEGE
 EatonEaton
 Marketelectrical.com carries CB of all these brands.Marketelectrical.com carries CB of all these brands.

7. Siemens Circuit Breakers at MarketElectrical.comSiemens Circuit Breakers at MarketElectrical.com
 Siemens Q115 15 Amp, 120/240 Volt
 Siemens Q120 20 Amp, 120/240 Volt
 Siemens Q215 Type QP Plug-In Circuit Breaker; 15 Amp, 2 Pole
 Siemens Q230 30 Amp,2 Pole 240-Volt Circuit Breaker
 Siemens Q250 Circuit Breaker; 50 Amp, 2 Pole
 Siemens 15 Amp Arc Fault Circuit Breaker, Full Module 10,000 A.I.C. 120V
 Marketelectrical.com carries CB of all these brands.Marketelectrical.com carries CB of all these brands.

8. Eaton Circuit Breakers at MarketElectrical.comEaton Circuit Breakers at MarketElectrical.com
 EATON Plug-In Replacement BR Breaker - 1P 20A BR120
 Eaton Breaker 2- 1 Pole 20A - DNPL2020
 EATON CUTLER Plug-In Replacement BR Breaker 2P 30A -
BR230
 EATON CUTLER Plug-In Replacement BR Breaker 2P 30A - BR230
 EATON CUTLER Plug-In BR Replacement Breaker - 2P 20A - BR220
 EATON Plug-In Replacement Br Breaker - 2P 100A - BR2100

9. Schneider Circuit Breakers at MarketElectrical.comSchneider Circuit Breakers at MarketElectrical.com
 Schneider Single Pole 15 Amp Tandem Circuit Breaker - QO115CP
 Square D #QO120CP 20A SP Circuit Breaker
 Schneider 1P 15AMP 120/240V Circuit Breakers - QO115
 SCHNEIDER Single Pole 20 Amp Tandem Circuit Breaker -
QO2020CP
 SCHNEIDER PIONEER Single Pole 15 Amp Stab-lok (NC) Plug-On Circuit B
NC015CP
 SCHNEIDER QO250CP - SQUARE D Double Pole 50 Amp QO Plug-On

10. GE Circuit Breakers at MarketElectrical.comGE Circuit Breakers at MarketElectrical.com
 GE Circuit Breaker; 15 Amp, 120/240 Volt, 1-Pole - THQP115
 GE Circuit Breaker 1-Pole 20-Amp Circuit Breaker - THQP120
 GE Breaker - 2-Pole 15-Amp Thin Series - THQP215
 Thin Series 2-Pole 30-Amp Circuit Breaker - THQP 230
 GE Circuit Breaker with Arc Fault Protection; 15 Amp, 1-Pole -
THQL1115A
 GE Breaker - 2-Pole 15-Amp Thin Series - THQP215
 www.Marketelectrical.com carries CB of all these brands.www.Marketelectrical.com carries CB of all these brands.

11. Thank YouThank You
Source : Arun DhruvalSource : Arun Dhruval