High Impedance Bus Differential Protection

The High Impedance Bus Differential Protection is a very interesting subject to study. A busbar is a critical component in a power substation. It ensures the proper connection of all incoming and outgoing feeders to a single voltage level system. Obviously, if a fault occurs on the bus itself and does not promptly clear, it may cause permanent damage to the … Read more

What is Nanocrystalline Core in CTs? A Complete Detail

A critical component of a CT is its magnetic core, which significantly influences its performance, accuracy, and efficiency. Accuracy is the most essential property of a current transformer. Traditionally, Cold-Rolled Grain-Oriented (CRGO) silicon steel has been the material of choice for these cores. Nowadays, a superior alternative is available on the market—nanocrystalline core material. In … Read more

Zero Current Crossing Method in A Circuit Breaker

This zero current crossing method is only applicable to alternating current circuit breaker. We all know that an alternating current naturally passes through zero at regular intervals (every half-cycle of the AC waveform). This method safely interrupts the alternating current at the natural zero-crossing of its waveform. Working Principle of a CB based on Zero … Read more

Testing of a Station Service Transformer as per Standards

Type Tests of a 33/0.415KV Station Service Transformer There are mainly three standards we follow for testing of a Station Service Transformer. These are IS : 1180 part 3 – 2021, CEA Guideline and CBIP Manual. Type Tests According to IS : 1180 part 3 – 2021 According to the latest version of IS 1180 … Read more

Details Current Ratings of a Circuit Breaker

In addition to the normal current rating of a circuit breaker (which is the current it can handle continuously during regular operation), there are two important categories of short-circuit current ratings that define how the circuit breaker performs during fault conditions: Rated Short Circuit Breaking Current The short-circuit breaking current of a circuit breaker consists … Read more

Current Ratings of an Electrical Equipment

Electrical equipment is designed to handle different types of current, and there are mainly three types of current ratings that apply to it: Normal Current Rating, Short Circuit Current Rating (for a specific time period), and Dynamic Current Rating. Let’s explain these in simple terms: Normal Current Rating The normal current rating of electrical equipment … 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 of a Vacuum Circuit Breaker

Type Tests for a 36kV Class Vacuum Circuit Breaker (VCB) As per IS: 13118, these type tests include: These tests are intended to ensure that the circuit breakers perform reliably, safely, and efficiently under various operating conditions. Routine Tests for a 36kV Vacuum Circuit Breaker (VCB) As per IS: 13118, the routine tests include the … Read more