Switch Disconnectors: Everything You Need to Know

Switch disconnectors are distribution equipment which is extensively used in factories as well as commercial and industrial setups for breaking circuits, manual switching, and isolating power supply. Wide varieties of such disconnectors are available in the market. However, before you purchase one, you must consider various factors including application areas, functionalities, and the benefits that the product offers. 

So, if you looking for information on switch disconnectors, you have come to the right place. This article aims to cover everything you need to know about switch disconnector isolators. 

What are switch disconnectors?

Also known as power isolators, switch disconnectors can help in disconnecting electrical equipment for repair and maintenance. 

Highly-powered electrical equipment needs to be completely discharged of electricity before beginning any kind of repair or maintenance work. Along with turning off the flow of electricity, the disconnector also helps in separating different parts of the electrical system. 

Switch disconnectors ensure the safety of equipment and people at the same time. They help minimise the risks of mechanical and electrical accidents, thus creating a safe working environment. This is particularly applicable during the time of repair work and maintenance. 

Switch disconnector isolators are used in diverse applications like power distribution, machinery, motor control centres, switchboards, and photovoltaic installations. These devices can close onto an existing short-circuit within their rated capacity limit with no risk at all to the equipment or the operators. 

Switch disconnectors are mainly used as emergency off-device. Therefore, they must be easily identifiable, accessible, and visible at all times by the operators. This is why switch disconnectors are always painted in specific colours, which are as per the electrical standards of the country or region. 

Understanding the difference between disconnectors and circuit breakers

Many people confuse circuit breakers and disconnectors and consider both types of equipment to be the same. However, there are many differences between the two electrical equipment, particularly when it comes to the services that they offer. 

The working objective of a switch disconnector is simple. The disconnector disconnects the current or power source so that maintenance, inspection, and repair jobs can be done easily and safely by electricians and mechanics. There are a wide variety of switch disconnectors available for this purpose. 

On the other hand, a circuit breaker can do many other tasks when compared to a switch disconnector. A circuit breaker makes, carries, and breaks the current under standard circuit conditions. A circuit breaker offers complete isolation whenever needed. 

A circuit breaker is more of a protective electrical device which helps in controlling the volume and flow of current. In this aspect, it is quite similar to a fuse. This feature is not present in a switch disconnector. 

In situations like short-circuit or overloading, the circuit breaker will simply break the circuit, keeping the household or the commercial space safe. Circuit breakers contain relays. These relays help in sensing the various errors in the circuit and send signals so that the contacts are closed to avert accidents. The majority of circuit breakers operate automatically. 

To sum up the differences between a switch disconnector and a circuit breaker, the switch disconnector is a power disconnecting device, which completely stops the flow of power in a circuit. This device is most commonly used along with a circuit breaker or a load switch. 

The circuit breaker on the other hand works as a switching device. It is specifically designed for cutting rated current and short circuit current. 

The working of both these devices together is complimentary and they work together to help in creating a safe work environment.

Read Also: All You Need to Know about Switch Disconnectors

How does a switch disconnector function – understanding the isolator working principle

The primary objective of a switch disconnector is to disconnect the electrical power. Disconnectors come with two mechanisms – they are either manually driven or motor-operated. It is important to choose the correct and proper operating mechanism and method for a particular substation. 

Auxiliary switches are an integral part of the disconnector mechanism. The switches offer a remote indication of disconnector position, electrical interlocking, and current transfer switching. Switch disconnectors contain two metal blades or contacts, which separate on the opening of the switch. With the closing of the switch, the contacts come together leading to the flow of electric current through the circuit. 

The opening and closing of the disconnector can be an automated process or handled manually. For manual operations, there is a lever or a knob in place. Whereas, the automated process is controlled via a relay or a switch. Many switch disconnectors have a spring-loaded mechanism for opening the contacts. These help in opening the contacts as soon as the electrical load gets removed from the switch. 

What are switch disconnectors used for?

A switch disconnector or a switch disconnector isolator helps in isolating power from any electrical equipment, which is connected to a circuit. This is mainly done for safety and security reasons, particularly during maintenance and repair works. In a large electrical distribution, the disconnectors break the electrical circuits to stop current flow. 

This is the reason that disconnectors are used extensively in various industrial and factory applications. Switch disconnectors are also applicable for motor-operated as well as manual disconnectors. During the time of operations, the disconnectors are paired with switches, which are linked with earthing wires. This is done for providing additional safety and security to professionals and electrical engineers when they are fixing complicated electrical issues or during maintenance and repair activities at the work areas. 

For large electrical substations, disconnectors with high voltage ratings are used together. The main purpose of using these disconnectors in electrical substations is to disconnect high voltage and extensive power in transformers and transmission lines for safe repair and maintenance works. 

However, do not think that electrical disconnectors can control circuits. Many people make the mistake of confusing the two operations. But disconnectors do not have the mechanism of controlling the circuit, they can only isolate power flow safely.

Areas of applications of switch disconnectors

A switch disconnector isolator or a fuse switch disconnector finds applications in various workstations in industries and factories. Let us take a look at some of the important places of their application:

Information Technology

In the Information Technology industry, there is wide use of switch disconnectors, particularly during repair and maintenance works. They are used in:

• Networks
• Data centres
• Computer rooms
• Telecommunications

Energy and Utilities

This is another area where you will find the extensive use of disconnectors to a great extent. Some of the areas include:

• Oil
• Solar 
• Water and wastewater
• Gas
• Wind
• Smart grid
• Hydropower

Industrial and Heavy Machinery Industry

Switch disconnectors are widely used in the industrial fields and the heavy machinery industry. Here are some industries which need this electrical equipment for sure:

• Mining and metals
• Pulp and paper
• Construction
• Material Handling
• Processing
• Agriculture
• Manufacturing
• Petrochemicals
• Pharmaceuticals

Buildings and architectural structures

Disconnectors as well as circuit breakers are a need of the hour in all kinds of buildings and architectural construction sites for additional security and safety. 

• Commercial offices
• Residential building
• Airports
• Public sector
• Education
• Healthcare
• Retail structure

Advantages of installing switch disconnectors

Now that we know in detail about what switch disconnectors are and what they are used for, how they function and so on, it is time that we discuss the excellent advantages that these devices offer. Some of the prominent advantages of using switch disconnectors are as follows:

• Extremely easy for installing and commissioning
• Offers high safety, security, and reliability for workers
• Offers a heightened degree of protection from hazards and accidents
• Requires minimal maintenance post installation
• High capacity for making and breaking
• Suitable and applicable for diverse applications
• Can be operated manually as well as can be automated too
• Can be mounted in different positions
• Provides guard against mechanical or electromagnetic vibrations

Schneider Electric – a reputed name offering only high-quality switch disconnectors

As varieties of switch disconnectors are available in the market in India, you must choose the one which is most suited to your requirements. Because switch disconnectors are safety devices, it is also advised that you buy one that is not only high quality but is sold by a reputed, trustworthy brand. It is also recommended that you talk to an electrician before making the final purchase of switch connectors.

One of the best places to look for high-quality switch disconnectors at reasonable rates is the Schneider Electric eshop in India. The Schneider Electric eshop is a one-stop destination for not just switch disconnectors, but also all things electrical that you might need. The eshop offers household electrical equipment like modular switches and smart home automation systems, to industrial electrical devices including push-button switches and circuit breakers.