Electrical Isolator - Types, Working & Its Applications

An electrical isolator switch is actually a switching device mainly used for the purpose of de-energizing a circuit for the purpose of maintenance and other similar processes. Standardly referred to as isolation switches, it’s a device that is intended to isolate circuits in the most efficient manner. They are adopted in many uses and circumstances such as the industrial and distribution of electrical energy.

Isolation switches find their application in high-voltage systems like substations, where they are used effectively to disconnect or isolate transformers, circuit breakers, or other electrical equipment. Therefore, unlike circuit control devices, isolation devices are not used to switch or to operate the current flow but are merely used to isolate the sections of a circuit. This isolation is required in the safe process of working with the electrical systems, such as the power cables’ maintenance and inspection.

These isolators can be classified as either fully automatic or semi-automatic depending on the specifications of the system they are to be incorporated in. They are very useful in the operation of electrical systems since they can be well-adjusted to meet the required standards.

This blog aims to give a broad outline of electrical isolators and the various electrical isolator types. It focuses on how these devices work, the purpose they serve in electrical systems, and their ubiquity in matters of safety and reliability of electrical networks. So, this blog is your ultimate electrical isolator selection guide.

What is Electrical Isolator?

An electrical isolator is a form of mechanical switch that is used selectively to break off part of an electrical circuit where isolation is likely to be required. Imperative to the regulation and safety of the electrical system, this device is necessary for management during the system’s maintenance. Isolator switches are designed to be switched only under no-load conditions; in other words, it is only switched when no current is flowing through the circuit. They are not intended to open on their own and one must never use an isolator to place a live circuit off.

Types of Electrical Isolators

Electrical isolators are important devices in power systems. These isolators are classified into three primary categories based on the system’s requirements:

Double Break Type Isolators

Double Break Type Isolators have three post-insulators. You will find a tubular contact or a flat male terminal within the central insulator and this terminal is set horizontally through the rotation of the middle post insulator. This rotation is made possible by a lever mechanism provided at the base of the given structure. This design guarantees a sharp separation of the circuits.

Single Break Type Isolators

Single Break Type Isolators consist of an arm contact divided into two parts: one part with the male contact and the other part with the female contact. These contacts move because of the relative movement of the post-insulator to which they are connected. Yet, on the opposite rotation of the post insulators, the arm contacts make contact, and thus, the isolator is closed.

Pantograph Type Isolators

Pantograph Type Isolators are preferred for their small size, occupying little space as compared to others. They form existing switchgear equipment; these are the post insulator and the operating insulator. The mobility of their structure enables them to work well especially in complex systems; this makes them suitable for current power systems.

In addition to the functional classification, electrical isolators are further categorized based on their location within the power system into the following types:

Bus Side Isolator

Bus Bus-side isolators are directly linked to the main bus. They have the essential duty of actuating individual portions of the bus to prevent the entire system from degrading and to support the power system’s dependability and stability.

Line Side Isolator

Line Side Isolators are available for connection in the circuit by use of a feeder line. They help in isolating individual lines, thus allowing safe maintenance and operational flexibility while at the same time not affecting the entire system.

Transfer Bus Side Isolator

Transfer Bus Side Isolators are connected to the circuit with the help of a transfer bus, mostly in relation to transformers. They afford an opportunity for isolation of the transfer bus for services such as maintenance or realigning of the system with no impacts on the rest of the working core units.

These classifications show the direction and the need to provide more specialized isolators to meet the diverse and complex presentations of today’s power system environments.

Electrical Isolator Working Principle

The working of isolator is very simple, and it can be used in both ways. These devices are frequently utilized as switches; such switches are called electrical isolator switches. Since there is a requirement to close or open the circuit by the switch, it has to be built in that way. However, they are often positioned to be stationary with the purpose of ensuring the working and troubleshooting are improved.

An electrical isolator switch is defined as a specific device that is intended to disrupt the circulation of current to a certain circuit for conducting secure maintenance and operation of electrical circuits. They are keyed in numerous electrical devices, such as kitchen appliances and electricity distribution networks. They are of various ratings according to their usage as single pole, double pole, three poles, four poles, fused, and battery isolator switch.

No matter what the rating is, to ensure proper functioning, it is essential to know how to maintain electrical isolators.

Also Read: What Is The Difference Between A Circuit Breaker And Isolator?

Summing Up

All of the isolators have specific functions and applications providing different means for disruption of electrical circuits in residential as well as industrial usage. It, therefore, can be said that an electrical isolator switch is very useful and is a necessity when it comes to electrical safety and reliability, hence making them key players in the current electrical network. So, choose the best ones from reliable providers. It is where Lauritz Knudsen Electrical & Automation can help you shop for the best isolators online.