Switchgear: Definition, Uses, and How to Choose the Right One

August 20, 2025 - Electrical Disconnectors Mexico

Switchgear

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What is an Electrical Disconnector?

An Electrical Disconnector is a mechanical device designed to open or close an electrical circuit, but with one key characteristic: it is not intended to interrupt the current when a load is connected. Its main function is to electrically isolate a part of the system so that it can be safely inspected, repaired, or maintained. In simple terms, we could compare it to a stopcock in a hydraulic system: it cuts off the flow for safe operation.

The disconnector ensures that, once opened, there is no electricity flow to the area requiring intervention. This is vital in industrial facilities, electrical substations, and distribution networks, where power circulates at very high voltages and currents.

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Main Functions of a Switchgear

Although it may seem like a simple piece of equipment, the switchgear performs critical functions for the safety and operation of electrical systems:

• Isolate sections of the circuit for maintenance without risk of electric shock.

• Avoid the circulation of current in areas where repair work is being carried out.

• Delimit energized and non-energized areas in substations and transmission lines.

• Control and manage the electrical grid , allowing partial outages without affecting the entire installation.

• Reduce the risk of failures and accidents during maintenance operations.

  
  

In many electrical projects, the disconnect switch acts as the first point of safety before accessing equipment such as transformers, power switches, or distribution systems.

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Types of Switchgear

The choice of the appropriate switchgear depends on the installation voltage, location, environmental conditions, and the required level of protection. The main types include:

1. Knife switchgear

   • Manually operated and highly visible, commonly used in medium voltage networks.

   • Its advantage is that the operator can visually confirm that it is open.

2. Indoor and outdoor switchgear

   • Interior : protected from the elements, ideal for electrical panels or control rooms.

   • Exterior : Designed to withstand extreme weather conditions.

3. Load switchgear

   • Unlike a traditional switchgear, it can open with a small current flowing, making it useful in certain operational maneuvers.

4. Medium and high voltage switchgear

   • Designed for voltages up to 400 kV in electrical transmission systems.

5. Fuse or gas switchgear

   • It integrates additional protection for rapid disconnections in case of short circuits or overloads.

     
     

In critical installations, two or more types of switchgear are often combined to achieve greater safety and operational flexibility.

EDMAR Electrical Installations

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When should a switchgear be used?

The switchgear is essential in any installation that requires isolation operations for maintenance or repairs. Some examples of uses include:

• Electrical substations : to isolate specific transformers or cells.

• Transmission lines : allow the flow of energy to be cut off at specific sections.

• Industrial plants : separate production areas without stopping the entire operation.

• Data centers : Isolate racks or electrical modules for maintenance without affecting operations.

• Hospitals : Keeping critical systems running while working in other areas.
  

In addition, it is important to use a disconnect switch when the installation requires compliance with safety regulations and safe working procedures under international standards.

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Tips for choosing the right switchgear

Selecting the right switchgear is not limited to "any switch that cuts off the power," but requires a technical analysis that considers:

1. Voltage level

   • Determine whether it is for low, medium or high voltage.

   • This will define the design and isolation capacity of the equipment.

2. Location

   • Indoor or outdoor, considering humidity, dust, temperature and sun exposure.

3. Nominal current capacity

   • It must withstand the maximum system current without risk of overheating.

4. Type of protection

   • Fuse, SF6 gas or conventional design depending on the risk level.

5. Standards and certifications

   • Comply with NOM and international standards such as IEC or ANSI.

   
   

   

   Power Plant

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Preventive Maintenance of Switchgear

Although switchgear are robust and long-lasting equipment, they require periodic inspections to ensure safe operation. Preventative maintenance includes:

• Visual inspection for wear, corrosion, or dust buildup.

• Lubrication of moving parts to ensure smooth operation.

• Check connections to avoid hot spots that could cause failures.

• Continuity and insulation testing to confirm compliance with rated values. Performing this maintenance on a scheduled basis not only prolongs the equipment's lifespan but also prevents unexpected power interruptions.

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Innovations and Trends in Switchgear

The technology applied to switchgears has evolved significantly in recent years. Today, there are models with:

• Integrated sensors that send status and wear alerts to remote monitoring systems.

• Motorized drive for remote operation, reducing risks to personnel.

• Compact and modular designs that facilitate installation in small spaces.

• Advanced materials offer greater resistance to corrosion and extreme temperatures. These innovations not only improve safety, but also increase efficiency and reduce long-term operating costs.
  

  

  Switchgear

An switchgear is much more than a simple accessory. It's a key tool for the safety of electrical installations and for ensuring the operational continuity of any project.

At EDMAR Group , we have high-quality switchgears and offer advice on selecting the ideal model for your project, ensuring compliance with regulations and a long service life.