Quiz on Electrical Engineering – A Complete MCQ Quiz Series

Test and enhance your electrical engineering knowledge with this interactive Electrical Engineering Quiz. The quiz randomly selects 20 multiple-choice questions from a large database of topics such as circuit breakers, transformers, lightning arresters, insulators, and power systems. You can choose between:All-Subject Mode – mix of questions from all topicsSubject-Wise Mode – focus on one subject … Read more

Earth Continuity Conductor or Cable (ECC) for EHV Cables

The Earth Continuity Conductor or ECC provides an alternate fault current path in EHV installations, limiting dangerous sheath voltage and safeguarding cable insulation. Sometimes, we also call it Earth Continuity Cable. We most commonly use single-core cables for underground high-voltage transmission systems. This is because 3-core high-voltage transmission cables, mainly above 33kV, are not easily … Read more

Types of Bus Arrangements in Substations – A Complete Guide

Single Bus System with Bus Sectionalizer Often, engineers adopt a single bus bar with a sectionalizing arrangement. Because it is cheap and simple. The figure just below shows a single bus bar with a sectionalizing arrangement. The scheme works best when the incoming and outgoing circuits are distributed evenly across the sections. When a single … Read more

Selective DC Scheme in Breaker Control Circuit

The Selective DC Scheme in circuit breaker control circuits is a specialized design used to enhance reliability and ensure fail-proof operation in power system protection and control. In a Selective DC Scheme, multiple (normally two) DC supplies are taken to ensure that control circuit of CB remains functional even if one of the supplies fails. … Read more

Spring – Spring Mechanism of Circuit Breaker – Explained

Spring-spring mechanism is the most commonly used circuit breaker operating mechanism today. It offers many advantages. Manufacturers use this as the simplest and most economical mechanism in circuit breakers. It also provides high reliability. This mechanism is much more compact than hydraulic or pneumatic mechanisms. Previously, engineers widely used spring-spring mechanisms for 11 kV indoor … Read more

Anti-Pumping Scheme in Circuit Breakers – A Complete Guide

In electrical power systems, circuit breakers play a crucial role in protecting equipment and ensuring the stability of the grid. However, improper operation of breakers can lead to major faults and unsafe conditions. One critical issue in breaker operation is multiple closing attempts before clearing a fault. This can occur due to a continuous closing … Read more

Minimum Oil Circuit Breaker | MOCB – Explained

Before entering the minimum oil circuit breaker (MOCB), let us recall our knowledge about the older version of the oil circuit breaker and which is the bulk oil circuit breaker. In a bulk oil circuit breaker,(BOCB) we use oil as the insulating medium.  Also, we use oil as the arc-quenching medium. So, to serve both … 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

SOTF Protection or Switch On To Fault Protection

We are going to discuss here in this article a clear idea about SOTF Protection. Sometimes it becomes necessary to open a circuit breaker just after closing. This is due to the presence of a fault during the closing of the circuit breaker. This type of condition may arise due to different reasons. Such as … Read more

What is SF6 CT? SF6 Current Transformer – Complete Guide

SF6 CT

Nowadays, SF6 gas-filled current transformers become popular modern type of CT used in high-voltage substations. It uses SF6 gas as its internal insulating medium instead of conventional insulating oil. We normally install SF6 CTs in voltage levels above 132 kV. A typical SF6 CT is a single-unit, live-tank type instrument transformer. Because it contains pressurized … Read more