Duty Cycle of a Circuit Breaker

A Circuit breaker is an essential component in electrical power system. It is designed to interrupt fault currents and hence protect equipment from damage. A crucial aspect of their performance is the duty cycle. The duty cycle defines the operational requirements and limitations of the breaker in terms of repeated opening and closing operations. Whenever … Read more

Testing on Clamp Connectors of Power Circuit

Type Tests of Clamp Connectors The tests are performed as per IS: 5561. Type tests are performed on 3 samples of same item Routine Tests on Clamp Connectors Acceptance Tests on Clamp Connectors as per IS: 5561 The number of samples for acceptance tests will be 0.5% (or as the nearest whole number) of the … Read more

Bulk Oil Circuit Breaker – History, Working & Drawbacks

In the early days, less 1910 or the early 20th century, most utilities used a bulk oil circuit breaker (BOCB) for high-voltage switching during that time. Earlier air circuit breakers served the purpose of switching high voltage and very high voltage current. But after the 19th century, engineers realized that mineral oil, or specially treated … Read more

What is Basic Insulation Level (BIL) – A Complete Guidance

Each high-voltage equipment requires adequate insulation to operate safely, reliably, and efficiently. Rated insulation levels indicate the amount of stress the insulation can handle during lightning strikes, sudden electrical surges, or power overloads. The IEC and Indian Standards (IS: 13118) have established clear global rules for these insulation levels to ensure consistent operation. Actually, an … Read more

Testing on Aluminium Bus Pipe

Type Tests of Aluminum Bus Pipe These tests are performed as per IS 5082 (1998). Routine Test of Aluminium Bus Pipe Acceptance Test of Aluminium Bus Pipes The acceptance tests of the aluminium bus pipes will be the same as the routine tests. Only difference is that, acceptance tests can be performed on the selected … Read more

Questions on 33KV Circuit Breaker – A Complete Session

What type of circuit breaker is generally used for the 36KV class? Ans: The 36KV class circuit breaker is normally an outdoor type Vacuum Circuit Breaker (VCB). Why is VCB Preferred in 33KV Outdoor Systems Over SF6 Circuit Breakers? Ans: VCBs offer a more economical approach for 33KV systems compared to SF6 circuit breakers. It … Read more

Rogowski Coil CT – A Complete Guide to Theory and Operation

Rogowski Coil CT

Before discussing the Rogowski Coil CT (Current Transformer), it is essential to understand the basic theory behind it. When current flows through a conductor, it creates a magnetic field around that conductor. If we place a ring-shaped magnetic core around the conductor, the magnetic flux lines concentrate inside the core. When we wrap a copper … Read more