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Learn about Vacuum Circuit Breakers — construction, working, testing, ratings, and advantages for reliable medium-voltage power switching.
What is a Vacuum Circuit Breaker? A vacuum circuit breaker is a current interruption device that uses vacuum as the arc-extinguishing facility. When the contacts open, the arc is quickly extinguished due to the absence of proper medium in the vacuum. We commonly refer to a vacuum circuit breaker as a VCB. We’ll cover here … Read more
Formation of Arc in Medium Before discussing the vacuum arc, let us recall the concept of arc formation in a medium like air, gas, or any other similar medium. Arc during closing contacts Let us switch on a circuit breaker online. Closing of this circuit breaker connects a load to a source. During closing, the … Read more
Introduction In modern medium-voltage power systems, vacuum circuit breakers play a dominant role in safe and efficient current interruption. Engineers prefer these breakers for their robustness, low maintenance requirements, and high dielectric recovery strength. A vacuum circuit breaker, also known as VCB, uses the unique properties of a vacuum to quench electrical arcs. Unlike SF6 … Read more
Before discussing the actual comparison, let’s look at the different media used in circuit breakers. These are air, oil, and SF6 gas. Nowadays, engineers have also developed some other gaseous media like compressed air, C4-FN mixtures (C4-FN/CO2 or C4-FN/N2), C5-FK mixtures (C4-FK/air or C4-FK/CO2), and pure N2 or N2/CO2 mixtures as insulating mediums. Certainly, some … Read more
We shall cover the constructional details of a vacuum interrupter along with its function, how it facilitates arc quenching, etc. Introduction to Vacuum Circuit Breakers Before entering into the detailed discussion about the vacuum interrupter, let us have a look at the basic concept of vacuum circuit breakers. A vacuum interrupter, which we also call … Read more
The article will focus on the contact design of vacuum interrupters. Before discussing the subject, let us consider why a specific design of contacts is required. The simplest form of contact is the butt-type contact, which has a plain and flat surface. This type of contact is suitable for vacuum circuit breakers with a rated … Read more
Rated Voltage: 36kV Rated Insulation Level:
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
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