36kV Switchgear: Ratings, Applications & Selection

36kV switchgear is high-voltage switchgear and controlgear used in power distribution systems where equipment must be suitable for a 36kV-class network. Depending on the design, it can include vacuum circuit breakers, disconnectors, earthing switches, busbars, protection relays, instrument transformers, and cable compartments.

36kV switchgear can be found in utility substations, industrial power systems, renewable energy projects, transformer substations, and other medium-voltage distribution applications.

For distributors and EPC contractors, selecting 36kV equipment requires more than checking the voltage rating. Rated current, short-circuit performance, insulation level, internal arc requirements, environmental conditions, applicable standards, and installation configuration should all be considered.

What Is 36kV Switchgear?

36kV switchgear is electrical switching and protection equipment designed for systems requiring a 36kV-class rated voltage.

Its main functions include:

• Switching electrical circuits
• Protecting feeders and transformers
• Isolating electrical equipment
• Controlling power distribution
• Connecting substations and feeders
• Providing safe operational isolation

A typical 36kV switchgear lineup may contain separate compartments for:

• Circuit breakers
• Busbars
• Cable connections
• Instrument transformers
• Low-voltage controls

The exact arrangement depends on the application and manufacturer.

For example, an industrial substation may require incoming and outgoing feeder panels, while a wind or solar project may require a different configuration for collector-system applications.

Why Use 36kV Switchgear?

36kV-class switchgear can be selected for distribution networks where the system voltage and insulation requirements call for this equipment class.

Potential applications include:

• Utility substations
• Industrial facilities
• Mining operations
• Solar farms
• Wind farms
• Battery energy storage projects
• Commercial infrastructure
• Transformer substations

The equipment’s rated voltage should always be checked against the actual system’s nominal and maximum operating voltage.

A project specification should also establish the required insulation level and fault withstand capability.

Key 36kV Switchgear Ratings

The voltage rating is only one part of a complete technical specification.

Rated Voltage

The rated voltage must be suitable for the system and applicable standard.

For a 36kV-class system, buyers should verify the equipment’s rated voltage and insulation coordination rather than relying only on the nominal network voltage.

Rated Current

The rated current determines how much continuous current the switchgear can carry under specified conditions.

The required rating should consider:

• Transformer capacity
• Feeder load
• Continuous operating current
• Future expansion
• Ambient conditions

Short-Circuit Breaking Current

The circuit breaker must be capable of interrupting the required fault current.

This value should be determined from the project’s electrical system study.

A higher voltage rating does not automatically mean a particular short-circuit rating.

Short-Time Withstand Current

This specifies the current the equipment can withstand for a defined period under the relevant test conditions.

It is especially important when evaluating busbars and other current-carrying components.

Peak Withstand Current

The peak withstand rating addresses the mechanical forces generated by high short-circuit currents.

Insulation Level

Insulation performance is another major consideration for 36kV switchgear.

Depending on the equipment and applicable standard, specifications can include:

• Power-frequency withstand voltage
• Lightning impulse withstand voltage

The correct values should be determined from the project requirements and applicable standards.

36kV Vacuum Circuit Breaker Switchgear

Vacuum circuit breakers are widely used in modern medium-voltage and high-voltage distribution equipment.

In a vacuum circuit breaker, current interruption occurs inside a sealed vacuum interrupter.

A 36kV VCB switchgear assembly can include:

• Vacuum circuit breaker
• Operating mechanism
• Protection relay
• Current transformers
• Voltage transformers
• Busbars
• Cable compartments
• Control and auxiliary circuits

Potential benefits of vacuum interruption include:

• Sealed interruption chamber
• No SF6 gas inside the vacuum interrupter
• Compact switching technology
• Relatively low routine maintenance requirements

However, buyers should distinguish between a 36kV vacuum circuit breaker and a complete 36kV switchgear assembly.

The complete assembly has additional requirements for enclosure construction, insulation, busbars, cable compartments, protection, testing, and installation.

Types of 36kV Switchgear

Metal-Enclosed Switchgear

Metal-enclosed switchgear uses a metal enclosure to contain and segregate electrical components.

Depending on the design, compartments can be provided for:

• Circuit breakers
• Busbars
• Cables
• Instrument transformers
• Controls

This configuration can be suitable for substations and industrial power distribution.

Vacuum Circuit Breaker Switchgear

VCB switchgear uses vacuum circuit breakers for switching and fault interruption.

It can be configured for:

• Incoming feeders
• Transformer protection
• Outgoing feeders
• Motor feeders
• Bus couplers

Ring Main Unit

36kV-class Ring Main Units can be considered for suitable distribution applications where a compact switching arrangement is required.

However, the specific RMU design and voltage rating must be verified because RMU products are available across different voltage classes.

Solid Insulated Switchgear

Solid insulated switchgear uses solid dielectric materials for insulation.

This technology can support compact designs and may be attractive for projects seeking alternatives to conventional SF6-based solutions.

Gas-Insulated Switchgear

Gas-insulated designs can provide compact equipment for space-constrained installations.

For projects with environmental requirements, buyers should identify the exact insulating medium and verify the manufacturer’s environmental specifications.

Where Is 36kV Switchgear Used?

Utility Substations

Utilities can use 36kV-class switchgear for:

• Distribution feeders
• Transformer connections
• Bus sections
• Incoming supplies
• Outgoing circuits

The exact voltage class depends on the utility’s network.

Industrial Power Systems

Industrial facilities may use 36kV switchgear for high-capacity power distribution.

Applications can include:

• Main incoming power
• Transformer feeders
• Process equipment
• Plant substations
• Distribution networks

Solar Farms

Large solar farms use collector networks to combine electricity from multiple transformer stations.

36kV switchgear can be considered when the collector system is designed around a matching voltage class.

Solar projects may also benefit from:

• Compact equipment
• Remote monitoring
• Low-maintenance designs
• Outdoor environmental protection
• Internal arc protection where required

Wind Farms

Wind power projects can use 36kV-class equipment in medium-voltage collection systems and substations.

Equipment selection should account for environmental conditions and the distance between electrical equipment and maintenance facilities.

Battery Energy Storage

Battery energy storage projects connect power conversion systems to transformers and the wider electrical network.

36kV switchgear can be used when the project’s voltage, fault level, insulation, and protection requirements match the equipment.

Mining and Heavy Industry

Mining and heavy industrial facilities can require higher-capacity medium-voltage distribution.

In these environments, buyers may place particular emphasis on:

• Robust construction
• Internal arc protection
• Environmental resistance
• Maintenance access
• Protection coordination

36kV Switchgear and IEC Standards

The applicable IEC standard depends on the specific type of switchgear or controlgear.

The IEC 62271 series provides a key standards framework for high-voltage switchgear and controlgear.

Different parts of the series address different equipment, including:

• Common requirements
• AC circuit breakers
• Disconnectors
• Earthing switches
• Metal-enclosed switchgear
• Gas-insulated switchgear

For 36kV switchgear, buyers should request the exact applicable standard and edition from the manufacturer.

Instead of accepting a general statement such as “IEC compliant,” ask for the specific standards and supporting test documentation.

This is particularly important for project procurement because the standard applicable to a complete switchgear assembly can differ from the standard applicable to an individual circuit breaker.

Internal Arc Protection for 36kV Switchgear

Internal arc performance can be an important consideration when switchgear is installed in locations where personnel may be present.

Applicable IEC requirements can include Internal Arc Classification (IAC) for relevant switchgear assemblies.

An IAC designation can specify:

• Accessibility
• Tested sides
• Test current
• Test duration

The required classification should be determined during the electrical and safety design stage.

Arc-resistant construction can involve:

• Reinforced panels
• Secure doors
• Controlled pressure relief
• Segregated compartments
• Defined exhaust paths

A key point for buyers is that a 36kV circuit breaker does not automatically make the complete switchgear arc resistant.

The complete assembly needs to be designed and tested for the claimed classification.

36kV switchgear used in a renewable energy substation

Indoor vs Outdoor 36kV Switchgear

Indoor 36kV Switchgear

Indoor switchgear is installed in an electrical building or dedicated switchroom.

Potential advantages include:

• Controlled temperature
• Reduced exposure to rain and dust
• Protected operating environment
• Easier maintenance access

The installation room must still meet the equipment manufacturer’s requirements.

Outdoor 36kV Switchgear

Outdoor equipment must be suitable for the environmental conditions at the installation site.

Consider:

• Ambient temperature
• Humidity
• Rain
• Dust
• Pollution
• Solar radiation
• Corrosive atmosphere
• Altitude

For outdoor renewable energy projects, environmental specifications can be particularly important because equipment may remain exposed for many years.

How to Select 36kV Switchgear

1. Confirm the Network Voltage

Start with the system’s nominal and maximum operating voltage.

Then verify the equipment rated voltage and insulation level.

2. Determine the Continuous Current

Calculate the expected feeder and transformer current.

Include expected future expansion where appropriate.

3. Establish the Fault Level

Determine the available short-circuit current through the project’s electrical study.

This information is necessary for selecting the appropriate circuit breaker and switchgear withstand ratings.

4. Choose the Switching Technology

Vacuum circuit breakers are commonly considered for modern 36kV-class applications.

Review:

• Rated current
• Breaking current
• Making current
• Operating sequence
• Mechanical endurance
• Electrical endurance

5. Define the Busbar Ratings

Check the required:

• Continuous current
• Short-time withstand current
• Peak withstand current
• Insulation performance

6. Define Internal Arc Requirements

If personnel can access the switchgear area, determine whether an IAC classification is required.

Specify the required accessibility and test conditions.

7. Check Environmental Conditions

Define whether the equipment will be installed:

• Indoors
• Outdoors
• At high altitude
• In a coastal environment
• In a polluted environment
• In a high-temperature location

8. Request Test Documentation

A qualified supplier should provide appropriate technical documentation, such as:

• Type-test reports
• Routine-test information
• Technical datasheets
• General arrangement drawings
• Single-line diagrams
• Installation instructions
• Maintenance manuals

36kV Switchgear for Renewable Energy

Renewable energy projects are an important application area for high-capacity medium-voltage distribution equipment.

Solar Power

A utility-scale solar farm may use a collector network to combine electricity from multiple inverter-transformer units.

36kV-class switchgear can be used where the collector network is designed around a matching voltage class.

The equipment may need to support:

• Multiple feeder circuits
• Transformer connections
• Protection relays
• Remote monitoring
• Outdoor installation
• Internal arc protection

Wind Power

Wind farms can use medium-voltage collector systems to combine power from multiple turbines.

Equipment selection should consider:

• Collector voltage
• Fault level
• Environmental conditions
• Cable lengths
• Protection coordination
• Remote site maintenance

Energy Storage

Battery storage facilities use electrical equipment to connect power conversion systems, transformers, and the grid.

The protection system should be coordinated with the characteristics of the inverter-based equipment.

Maintenance of 36kV Switchgear

Maintenance requirements depend on the switchgear design and operating environment.

Vacuum-based equipment may reduce certain routine maintenance requirements, but it should not be described as completely maintenance-free unless the manufacturer specifically supports that claim.

A maintenance program may include:

• Visual inspection
• Circuit breaker operation checks
• Protection relay testing
• Electrical connection inspection
• Interlock testing
• Insulation checks
• Functional testing

The manufacturer’s maintenance instructions should take priority for the specific product.

36kV switchgear used in a renewable energy substation

Frequently Asked Questions

What is 36kV switchgear?

36kV switchgear is high-voltage switchgear and controlgear designed for power distribution systems requiring equipment suitable for a 36kV-class rated voltage.

What is 36kV switchgear used for?

It can be used in utility substations, industrial facilities, solar farms, wind farms, battery energy storage projects, mining operations, and other power distribution systems.

Is 36kV switchgear medium voltage?

Industry terminology can vary. IEC uses the broader term high-voltage switchgear and controlgear for equipment above 1kV, while utilities and manufacturers commonly classify many systems in this range as medium voltage. The applicable standard and project specification should be used to define the equipment requirements.

What circuit breaker is used in 36kV switchgear?

Vacuum circuit breakers are commonly used in modern 36kV-class switchgear. The exact circuit breaker must be selected according to the required voltage, current, fault interruption, insulation, and operating duty.

Can 36kV switchgear be SF6-free?

Yes. Depending on the design, 36kV-class switchgear can use vacuum interruption combined with air or solid insulation or other alternative technologies.

Is 36kV switchgear suitable for solar farms?

It can be suitable for solar collector systems where the project voltage, fault level, insulation requirements, protection scheme, and environmental conditions match the switchgear specifications.

Does 36kV switchgear need internal arc protection?

The requirement depends on the installation, personnel access, project specification, applicable standards, and safety assessment. Where required, the exact IAC classification should be specified.

What standards apply to 36kV switchgear?

The applicable requirements depend on the equipment type. Relevant parts of the IEC 62271 series are commonly used for high-voltage switchgear and controlgear.

How do I choose a 36kV switchgear supplier?

Compare the supplier’s rated voltage and current, fault ratings, applicable IEC standards, type-test documentation, IAC capability, product design, customization options, manufacturing quality, delivery capability, spare parts, and technical support.

Conclusion

36kV switchgear provides a flexible solution for utility, industrial, renewable energy, and infrastructure power distribution systems.

However, the correct equipment cannot be selected from the voltage rating alone. A complete specification should address rated current, short-circuit performance, insulation level, circuit breaker technology, busbar ratings, internal arc requirements, environmental conditions, standards, and lifecycle support.

For distributors and EPC contractors, requesting complete technical documentation and test evidence is especially important when comparing 36kV switchgear manufacturers.

Depending on the project, 36kV vacuum circuit breaker switchgear, solid insulated switchgear, and other alternative-insulation solutions can provide different approaches to modern power distribution.

The best choice is ultimately the configuration that matches the electrical system, installation environment, safety requirements, and applicable standards—not simply the product with the highest rating.