Isolated circuit breaker

Types of isolated circuit breakers

Isolated circuit breakers are slowly gaining popularity due to their importance and performance parameters. These devices also help in the safe and effective operation of various power systems. These circuit breakers come in various configurations damping which helps with specific applications and system requirements. The most important and widely used types include the following.

Air-insulated isolated circuit breakers

These circuit breakers are the most widely used type. They use air as insulation or as an operating medium for the contacts and are suitable for almost any application. With these breakers, the main features are reliability and robustness. These features come into play especially during harsh ambient conditions. Because of their non-environmentally harmful properties, they are commonly used in substations in power companies, factories, and infrastructure projects.

Gas-insulated isolated circuit breakers

These circuit breakers are more compact than the air-insulated ones. They utilize sulfur hexafluoride gas (SF6) as insulation. Because of the smaller spatial requirements, these gas-insulated circuit breakers work in areas with high population density. It is very common to see them in underground substations or in mobile power systems. Circuit breakers of this kind also have high reliability and low maintenance.

Oil-insulated isolated circuit breakers

These types of circuit breakers are based on traditional designs, which use oil both as an insulator and a vehicle for the operation of the circuit breaker mechanism. They are mainly used in medium-voltage networks for industrial plants. These types are considered conventional because, despite the evolution of more modern types of isolated circuit breakers, these ones remain popular in power networks of industrial enterprises. The main advantage is that they are highly durable and work well in demanding environments.

Hybrid insulated circuit breakers

As the name suggests, these circuit breakers combine the air and gas insulation concepts. What this means is that they use air-insulated zones for the main switching functions and gas-insulated zones for secondary switching. This gives the circuit breaker a design that provides better reliability, functionality, and compactness. These types of circuit breakers are ideal for all containment applications where technology and space requirements intersect.

Durability and material

In isolated circuit breakers, the Internals have to be tough. This is because they have to be able to withstand harsh operating conditions, including severe weather, large temperature fluctuations, and exposure to corrosive elements.

The durability is not just for the mechanics but also for the materials used in constructing isolated circuit breakers. They have to be resilient even in hostile environments, so the isolated circuit breakers are constructed of high-grade, corrosion-resistant materials. These materials include stainless steel, aluminum alloys, and reinforced polymers.

The operational wear and tear of any equipment is a major consideration for people who use that equipment. Fortunately, isolated circuit breakers have limited operational wear and tear. They have very long lifespans due to their designs, which incorporate several maintenance-free components, especially in gas and hybrid insulated circuit breakers.

Finally, in terms of durability, the circuit breakers can withstand short-circuit currents, which are extremely high currents that occur for a very short duration.

Commercial use cases

Isolated circuit breakers are important components for controlling and protecting electrical equipment. Their main function is to maintain electrical safety in various commercial settings. The following are several industrial applications of isolated circuit breakers.

Power generation and electrical substation management

Isolated circuit breakers are used in self-generating units such as solar and wind farms. They ensure that all protective devices are functioning as they should. These circuit breakers also help manage energy flows and improve system reliability. Another area where isolated circuit breakers are used is in electrical substations, where they help isolate faulted equipment and improve maintenance capability.

Industrial facilities

In industrial facilities with large machinery and process equipment that require robust power supply protection, isolated circuit breakers are widely used. They are prime protectors of motors, generators, and large equipment, isolating faults and preventing damage to the production line.

Commercial and high-rise buildings

There has to be a protective device to ensure safety in the electrical systems of commercial and high-rise buildings. This is where isolated circuit breakers fit in. They protect electrical distribution systems, ensuring the reliability of the power supply for lighting, HVAC systems, and other essential services.

Renewable energy systems

With the move towards greener energy, isolated circuit breakers are increasingly making their way into renewable energy systems such as solar photovoltaic (PV) and wind power. They protect the equipment while also ensuring that the generated power is safely integrated with the electrical grid.

Data centers

Data centers are one of the most critical areas for the usage of isolated circuit breakers. They provide protection and ensure redundancy in the electrical distribution systems. This, in turn, guarantees a continuous power supply for critical IT infrastructure, which cannot afford any downtime.

Transportation systems

Isolated circuit breakers also find their way into transportation systems such as metro, rail, and marine electrical systems. They protect vital electrical systems.

How to choose isolated circuit breakers

To select the most appropriate isolated circuit breaker, considering the following key factors that will influence the decision is important.

• the voltage level: another important consideration when selecting an isolated circuit breaker. The right voltage level should correlate with the operational requirements of the specific power system. For example, air-insulated circuit breakers are better suited for low and medium voltages, while gas-insulated circuit breakers are more applicable for high voltages.
• Maintenance and operating costs: maintenance-free circuit breakers, such as gas and hybrid insulated circuit breakers, can reduce long-term costs. However, air-insulated circuit breakers may require more frequent maintenance, which could increase overall operational costs.
• The environmental conditions: compared to gas-insulated circuit breakers, isolated circuit breakers designed for harsh external environments require more robust materials, like air-insulated circuit breakers. These types have a larger footprint. Gas-insulated circuit breakers are best suited for an area where space is limited. They are also the most environmentally friendly option because their operating gas can be recycled and does not harm the environment.
• the short-circuit rating: this rating indicates the ability of the circuit breaker to withstand high fault currents for a very short duration. The short-circuit rating of an isolated circuit breaker must be higher than that of the system it will protect. Some isolated circuit breakers, like the oil-insulated ones, do not have high short circuit ratings.
• The system fault: it is equally important to ensure the consistency of the breaker with the system fault. This mainly depends on the network type. For example, if the network in question is a low-fault network, an air-insulated circuit breaker is ideal.

Q&A

Q1. What role do isolated circuit breakers play in promoting safety with electrical systems?

A1. Isolated circuit breakers help promote safety by providing a barrier between the operating person and the high-voltage components. They also ensure that the system can be safely maintained without the risk of electric shock, thus minimizing downtime for maintenance and reducing the likelihood of accidents.

Q2. What is the operating principle behind isolated circuit breakers?

A2. The operating principle is based on the need to isolate high-voltage circuits for maintenance and safety purposes. And this is done by ensuring no direct contact between people and the live parts while allowing the circuit to be opened and closed safely.

Q3. Do isolated circuit breakers require frequent maintenance?

A3. Isolated circuit breakers require little to no maintenance, especially the gas and hybrid insulated types. This is a huge selling point for them as limited maintenance means less operational downtime.

Q4. Are isolated circuit breakers environmentally friendly?

A4. Yes, most of the gas-insulated types are environmentally friendly. The gas used in isolation has no harmful effects on the ecosystems around them.

Q5. Can isolated circuit breakers be used in renewable energy applications?

A5. Yes, they are commonly used to ensure the safe operation of the electrical systems of renewable energy sources like solar and wind power.