Switchgear

Why ammeter is connected in series?

An Ammeter is a device used to measure the current flow through a conductor. The name is derived from the unit of current, Ampere. This article explains why is ammeter connected in series but not in parallel. An ammeter is either connected in series to the line along which the flow of current is measured … Read more

Miniature circuit breaker (MCB) – Principle of operation

Miniature circuit breakers commonly known as MCB, are mechanically operated switches cum circuit protection devices. It is an electro-mechanically operated automatic circuit protection device and is used to interrupt a circuit during overload and short circuits. It can be used as an alternative to fuses for domestic applications. They can be reused even after the … Read more

MCB Trip Curves – B, C, D, K, and Z trip curves

MCB (Miniature circuit breaker) is a re-settable device designed to protect a circuit from short circuits and overcurrents. The trip curve of an MCB (B, C, D, K, and Z curves) tells us about the trip current rating of Miniature Circuit breakers. The trip current rating is the minimum current at which the MCB will … Read more

Contactor – Construction, Operation, Application and Selection

A contactor is a switching device, widely used for the switching of motors, capacitors (for power factor correction), and lights. As the name indicates it is used to make or break contacts like an ordinary on-off switch. The only difference is that the contactors have an electromagnet that holds the contacts when energized whereas switches … Read more

Difference between RCCB and RCBO

RCCBs and RCBO are residual current protection devices. Residual current protection is achieved by monitoring the flow of current in the line and neutral. In a healthy circuit, the current flow through the line will be equal to the return flow in the neutral. In the case of any abnormalities, this return flow may not … Read more

Difference between MCCB and RCCB

Difference between MCCB and RCCB MCCBs and RCCBs are circuit protection devices with two different application. When the former protect against overload and short circuit, the later protects against Residual currents and electric shock. MCCB- Molded Case Circuit Breakers Moulded Case Circuit Breakers protect against overcurrent and short-circuits only unless otherwise, they have inbuilt residual protection. MCCBs trip as … Read more

Difference between MCB and MCCB

MCBs and MCCBs have commonly used circuit protection devices. These devices provide protection against overcurrent and short circuits. In this article, let us discuss the difference between MCB and MCCB. Overview of MCB: These are thermal / thermo-magnetic devices Provides protection against overcurrents and short circuits. Available up to 100A and have a maximum short … Read more

What is Comb Busbar?

Comb busbar is one of the most basic switch gear instruments. The main purpose of a comb busbar is to distribute power to switch gear components such as MCBs. There are two types of comp busbar viz, single phase comp busbar and three phase comb busbar. It can be found in small distribution boards that you … Read more

What is ammeter selector switch?

Untitled- ELECTRICAL CLASSROOM

Ammeter selector switch is basically a normal three position switch. In large Electrical distribution panels, an ammeter is used to monitor the current through each line.

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