In this topic, you study the Difference between Isolator and Circuit Breaker.
Circuit Breaker Symbol
Isolator Symbol
The difference between Isolator and Circuit Breaker as
| Isolator | Circuit Breaker |
| Operation is on NO load. | Operated ON load/on the occurrence of a fault. |
| No arcing during ON-OFF, so no arc quenching provision. | The current is interrupted and hence heavy arc is produced. Arc quenching facility is provided. |
| Its operation is manual or manual plus mechanical or pneumatic. | Manually operated in normal condition and automatic tripping in fault condition. |
| No definite current capacity and specifications. | C.Bs. are specified by breaking capacity, making capacity, etc. |
| Visible operation in open-air (opening and dosing of contacts). | Operation in the oil or gas chamber (not visible). |
| Noiseless operation. | Big sound on operation. |
| Cheaper. | Costly. |
| No periodic maintenance required, only contact cleaning. | Periodic maintenance is necessary. |
| There are very few types: Vertical breaking, Horizontal breaking, & Pentagonal type. | Wide varieties like Air break CB, ABCB, MCB, MCCB, OCB, SF6, DCB VCB etc. |
| For safety and maloperation, it is interlocked. | C.B. and isolators interlocked to avoid maloperation. |
| Occupy less space. | Occupy more space. |
| No tripping circuit. | Requires tripping circuit for operation. |