Where is a Switchgear required and what regulations apply?
- Grupo Edmar
- 6 days ago
- 4 min read
Updated: 5 days ago
August 28, 2025 - Installation of a Switchgear.
What is an Electrical Disconnector or Switchgear?
An switchgear, is a fundamental piece of equipment in any electrical installation, whether high, medium, or low voltage. Its function is very clear: to visibly isolate a circuit to ensure the safety of those working on it.
This means that when a technician needs to intervene on a line, substation, or facility, the disconnect switch ensures that that part of the system is completely disconnected from the power supply. Unlike a switch or circuit breaker, which can cut off current under load, the disconnect switch should only be activated when the circuit is already out of service.
In short: the switchgear does not protect against faults , but rather guarantees a visible and safe cut-off for operation and maintenance work.
Common Locations for the Installation of Switchgear.
Switchgear are not placed randomly, but at strategic points along the electrical grid, allowing specific sections to be maneuvered and secured. Some of the most common locations are:
Electrical substations: Here, they serve the function of dividing the transmission or distribution network into blocks. For example, if a transformer fails, the switchgear allows that section to be isolated without taking the entire substation out of service.
Electrical connections: In industrial or commercial installations, these are usually placed at the power inlet, to provide a visible and safe disconnection point between the public grid and the customer's internal system.
Underground networks: Pedestal-type switchgear allow the circuit to be opened from the surface without having to access underground chambers, which speeds up maintenance work.
Photovoltaic systems and renewable energy: These are key to safely disconnecting solar panels or wind turbines, especially when servicing inverters or electrical panels is required.
Large buildings and facilities: Shopping malls, hospitals, and airports often have disconnect switches to divide critical areas and ensure service continuity in the event of maintenance.
In general, its installation depends on three factors: accessibility, safety and operational needs.
Applicable Mexican Regulations.
The proper installation of switchgear in Mexico is regulated by various official standards that seek to protect both users and workers:
NOM-001-SEDE-2012 and 2021: The most important standard for low-voltage electrical installations. It defines how and where disconnection devices such as disconnect switches should be placed, ensuring reliable and accessible disconnection.
NOM-002-SEDE-2021: Oriented towards protection and maneuvering equipment, also covering characteristics that switchgear must meet in terms of insulation and electrical resistance.
Federal Electricity Commission (CFE) Standards: Documents such as G0100-03 or G0100-10 establish the technical parameters for equipment that forms part of the distribution network, where switchgear are a key component.
In short, these standards ensure that installed equipment meets quality, safety, and reliability standards, which are essential for electrical projects in Mexico.
Technical Requirements for Installation.
For a switchgear to function correctly and ensure safety, certain technical points must be met during its installation:
Height and accessibility: The maneuvering point should be at a comfortable height (approx. 1.0 to 1.1 m from the ground), making it easier for personnel to work.
Visible separation: When a switchgear is opened, there must be a physical and visible distance between contacts, confirming that the circuit is actually disconnected.
Mechanical protection: Equipment and conductors must withstand the stresses generated by fault currents.
Preventative maintenance: Periodic checks for lubrication, screw tightness, and contact condition are required. A poorly maintained switchgear may jam during operation or even generate an electric arc.
Installation environment: If installed outdoors, they must be protected from rain, dust, and corrosion. In industrial environments, sealed metal enclosures are common.
A clear example: in an industrial plant where there is a lot of metal dust, a switchgear without the appropriate enclosure can deteriorate quickly and fail at the most critical moment.
Types of Disconnectors and their Applications.
Not all switchgear are the same; there are different types, designed for specific applications:
High voltage: They are used in power transmission and allow the insulation of entire lines of several kilometers.
Low voltage: Most common in buildings, businesses, or small industries. They are used to easily disconnect circuits.
SF6 gas switchgear : They use this gas as an insulator, very useful in places where high security and little physical space are required, such as urban substations.
Pedestal type: These are ideal for underground or rural networks, as they are installed outdoors and allow for easy operation from the surface.
Indoor and outdoor switchgear: Depending on whether they are placed inside a panel or exposed to the elements.
The choice depends on the working voltage, the physical environment and the type of electrical installation.
Relevant International Standards
In addition to Mexican regulations, many projects must comply with international standards that guarantee compatibility and safety in different countries:
IEC 62271-102: Defines specifications for high-voltage disconnecting and earthing switches.
IEEE C37.122: Standard used in America for SF6 gas-insulated switchgear.
ISO 14001: Related to environmental management, especially important in equipment that uses high-impact gases, such as SF6.
These standards are especially relevant when working with export projects, multinational companies, or critical facilities that must comply with international certifications.
Importance of Training and Maintenance.
It's no use having the best equipment if the staff doesn't know how to use it or if its maintenance is neglected. In this regard:
Training: Technicians must know how to operate a switchgear, what safety protocols to apply, and the risks associated with its operation.
Maintenance: Periodically check lubrication, hardware, insulation, and the condition of the contact blades. A poorly adjusted switchgear can generate heat and fail over time.
Safety protocols: Lockout/tagout (LOTO) procedures are always recommended, preventing anyone from energizing the system while another worker is working.
This not only protects personnel, but also ensures the reliability of the electrical system and reduces costs due to unexpected failures.
Security and Support for your Project.
The switchgear is much more than a "switch": it is a key device for the safety, reliability, and operation of electrical systems. Installing it in the right place and in compliance with current regulations is an investment that protects both personnel and infrastructure.
At Grupo Edmar, we know how important it is to have the right equipment for each project. If you need advice on choosing the ideal switchgear or ensuring your installation complies with regulations, we can help you find the best solution for your operation.
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