Electrical substations and distribution systems increasingly need to deliver reliable power while using limited installation space. This is particularly important in urban substations, commercial buildings, data centers, renewable-energy projects, and industrial facilities.

Compact switchgear is switchgear designed to provide switching, protection, isolation, and distribution functions within a relatively space-efficient configuration. Compact MV switchgear can combine circuit breakers, busbars, protection devices, and cable connections into a smaller footprint than some conventional arrangements.

The exact size and configuration depend on the switchgear technology, voltage rating, current rating, insulation system, and manufacturer.

What Is Compact Switchgear?

Compact switchgear is a switchgear solution designed with an emphasis on efficient use of installation space.

It can be used for:

• Medium-voltage power distribution
• Substations
• Industrial plants
• Solar power plants
• Wind farms
• Battery energy storage systems
• Data centers
• Commercial buildings
• Utility networks

The term compact switchgear describes a design characteristic rather than one specific switchgear technology.

For example, compact equipment may use:

• Vacuum circuit breakers
• Gas insulation
• Solid insulation
• Air insulation
• Integrated modular designs

Therefore, buyers should evaluate the actual technology and technical ratings rather than selecting a product solely because it is marketed as “compact.”

How Does Compact Switchgear Work?

The basic electrical function is similar to other switchgear.

Power enters the switchgear through an incoming feeder and is distributed through busbars to outgoing circuits.

A simplified arrangement is:

Incoming Power
      │
      ▼
┌──────────────────┐
│ Compact MV       │
│ Switchgear       │
│                  │
│ Circuit Breaker  │
│ Busbar           │
│ Protection       │
└───────┬──────────┘
        │
   ┌────┼────┐
   ▼    ▼    ▼
Feeder Feeder Transformer

The switchgear can provide:

• Circuit switching
• Fault interruption
• Electrical isolation
• Protection
• Measurement
• Earthing functions
• Local or remote control

The specific functions depend on the switchgear design.

Compact vs Conventional Switchgear

Compact switchgear and conventional switchgear can perform similar fundamental electrical functions, but their physical arrangements may differ.

Compact does not automatically mean better.

The correct choice depends on:

• Available space
• Electrical ratings
• Maintenance requirements
• Environmental conditions
• Project budget
• Applicable standards
• Future expansion

Main Types of Compact Switchgear

Compact switchgear can be classified according to its insulation and switching technology.

Compact Air-Insulated Switchgear

Air-insulated switchgear uses air as the primary insulation medium.

It can be suitable for many medium-voltage distribution applications.

Advantages can include:

• Familiar technology
• Accessible components
• Straightforward maintenance concepts
• Broad application experience

The physical dimensions depend on the design and voltage class.

Compact Gas-Insulated Switchgear

Gas-insulated designs use an insulating gas or gas mixture within sealed compartments.

They can achieve a relatively compact arrangement because the insulation system allows components to be positioned closer together.

However, buyers should understand the exact gas technology and environmental characteristics.

Compact Solid-Insulated Switchgear

Solid insulation can be incorporated into compact MV switchgear designs.

Potential benefits include:

• Compact construction
• Reduced exposure of energized components
• Alternative insulation architecture

The specific insulation system and test evidence should be evaluated for the proposed equipment.

Compact Vacuum Switchgear

Vacuum circuit breakers are widely used in medium-voltage applications.

In a vacuum circuit breaker, the interruption process occurs inside a vacuum interrupter.

The surrounding switchgear can use an appropriate insulation technology according to the product design.

Compact MV Switchgear

Compact MV switchgear is particularly relevant where medium-voltage electrical distribution must fit into a limited area.

Applications include:

• Secondary substations
• Industrial substations
• Solar collector systems
• Wind farm substations
• BESS facilities
• Data centers
• Commercial power systems

A compact MV lineup may integrate:

• Incoming feeder
• Outgoing feeders
• Circuit breakers
• Busbars
• Protection relays
• Current transformers
• Voltage transformers
• Earthing switches

The exact arrangement depends on the project single-line diagram.

Compact Switchgear for Substations

Substations often have multiple pieces of electrical equipment competing for limited space.

Compact switchgear can help organize the MV distribution section efficiently.

A typical arrangement could include:

Utility/Grid → MV Switchgear → Transformer → LV Distribution

Or:

Transformer → MV Switchgear → Multiple Distribution Feeders

For secondary substations, a compact configuration can be particularly useful when the substation has limited physical dimensions.

RMU and Compact Substations

Ring main units are another example of space-efficient MV distribution equipment.

An RMU can integrate switching and protection functions into a relatively compact enclosure.

Applications can include:

• Urban distribution
• Commercial buildings
• Industrial facilities
• Renewable-energy installations
• Secondary substations

The appropriate equipment depends on the network topology and protection requirements.

Compact Switchgear for Renewable Energy

Renewable-energy projects can benefit from space-efficient electrical equipment.

Solar Power Plants

Solar projects may use compact MV switchgear for:

• Inverter transformer feeders
• Collector feeders
• Substation distribution
• Auxiliary power
• Grid connection

A typical electrical path is:

PV Panels → Inverter → Transformer → MV Switchgear → Grid

Large solar projects may require multiple MV feeders and switchgear panels.

Wind Farms

Wind farms can use compact MV switchgear in:

• Turbine transformer systems
• Collection networks
• Substations
• Auxiliary systems

Compact equipment can be useful where substation buildings or electrical rooms have limited floor area.

Battery Energy Storage Systems

BESS installations may have strict site constraints.

A typical configuration can be:

Battery → PCS → Transformer → MV Switchgear → Grid

Compact switchgear can help reduce the space required for the MV electrical section.

Compact Switchgear for Data Centers

Data centers require highly reliable electrical distribution while often operating within constrained building spaces.

Compact MV switchgear can be used around:

• Utility incoming supplies
• Transformers
• Generators
• Medium-voltage distribution
• Redundant electrical paths

The design should consider:

• Redundancy
• Protection coordination
• Maintainability
• Cable routing
• Remote monitoring
• Equipment access

Space efficiency should not come at the expense of safe access or maintainability.

Benefits of Compact Switchgear

1. Reduced Footprint

The most obvious advantage is efficient use of installation space.

This can be valuable when electrical rooms are small or expensive to expand.

2. Flexible Installation

Compact equipment can provide additional layout flexibility.

This can simplify equipment placement within:

• Substation buildings
• Electrical rooms
• Skids
• Containerized systems

3. Suitable for Urban Applications

Urban substations often face land and building constraints.

Compact MV switchgear can help accommodate electrical distribution equipment within limited areas.

4. Integration of Functions

Some compact designs integrate multiple functions into a single assembly.

This can simplify the overall equipment arrangement.

5. Potentially Simplified Project Layout

A smaller switchgear footprint can create more room for:

• Transformers
• Cable systems
• Auxiliary equipment
• Maintenance access

However, the actual layout benefit must be evaluated from the complete installation drawing.

Is Compact Switchgear Easier to Maintain?

Not necessarily.

Compact does not automatically mean maintenance-free.

Maintenance requirements depend on the switchgear technology, construction, operating environment, manufacturer instructions, and duty cycle.

Before selecting compact switchgear, buyers should review:

• Access to circuit breakers
• Cable compartment accessibility
• Inspection points
• Interlocking
• Test access
• Spare parts
• Manufacturer maintenance instructions

A smaller footprint should still provide appropriate safe working access.

SF6-Free Compact Switchgear

Compact switchgear does not have to mean SF6 switchgear.

Depending on the application, manufacturers can develop compact solutions using:

• Vacuum interruption
• Air insulation
• Solid insulation
• Alternative insulation technologies

SF6-free compact MV switchgear can therefore be considered for projects with environmental requirements.

However, “SF6-free” should be evaluated at the complete assembly level.

Buyers should ask:

• What insulation medium is used?
• Is SF6 present anywhere in the assembly?
• What circuit-breaker technology is used?
• What are the rated electrical parameters?
• What test documentation is available?
• Which applicable standards are satisfied?

IEC Standards for Compact Switchgear

The applicable standards depend on the equipment design.

For many medium-voltage applications, relevant parts of the IEC 62271 series may apply.

Examples include standards addressing:

• Common specifications
• AC circuit breakers
• Disconnectors and earthing switches
• Metal-enclosed switchgear
• Gas-insulated switchgear
• Prefabricated substations

For applicable metal-enclosed MV switchgear, IEC 62271-200 is particularly relevant within its defined scope.

The buyer should specify the applicable standard and edition in the technical specification.

Internal Arc Classification

Where required, buyers can specify an appropriate internal arc classification for applicable switchgear.

The classification relates to tested performance under defined internal-arcing conditions.

The installation arrangement matters, including:

• Accessibility
• Switchgear orientation
• Room configuration
• Pressure-relief arrangements
• Personnel protection requirements

How to Select Compact Switchgear

The selection process should begin with the electrical system rather than the physical footprint.

1. Determine System Voltage

Define:

• Operating voltage
• Rated voltage
• Frequency
• Insulation level

Common MV classes can include 12 kV, 24 kV, and 36 kV depending on the network.

2. Determine Rated Current

The switchgear must carry the required continuous current under the specified conditions.

Consider:

• Transformer rating
• Feeder loading
• Generator output
• Busbar loading
• Future expansion

3. Calculate Short-Circuit Requirements

Determine the prospective fault current at the installation point.

Check:

• Breaking capacity
• Short-time withstand current
• Peak withstand current

4. Define the Configuration

Determine:

• Number of incoming feeders
• Number of outgoing feeders
• Transformer feeders
• Bus sections
• Bus coupler
• Metering panels

5. Define Protection

Specify required:

• Protection relays
• CTs
• VTs
• Interlocking
• Trip circuits
• Communication

6. Check Physical Dimensions

Review:

• Width
• Height
• Depth
• Cable-entry direction
• Access requirements
• Maintenance space

Do not assess compactness only from the manufacturer’s headline dimensions.

7. Consider Environmental Conditions

Evaluate:

• Ambient temperature
• Altitude
• Humidity
• Pollution
• Dust
• Corrosion
• Seismic conditions where applicable

8. Verify Testing

Request relevant:

• Type-test evidence
• Routine-test documentation
• Factory acceptance testing
• Product certificates or declarations where applicable

Compact Switchgear Buyer Checklist

Before placing an order, verify:

Electrical

• Rated voltage
• Rated current
• Frequency
• Short-circuit rating
• Insulation level

Mechanical

• Overall dimensions
• Cable entry
• Access
• Enclosure
• Installation arrangement

Protection

• Circuit breaker
• Protection relay
• CT/VT
• Interlocking
• Control system

Standards

• Applicable IEC 62271 part
• Current applicable edition
• Local standards
• Utility requirements

Environmental

• Indoor/outdoor
• Temperature
• Altitude
• Pollution
• Humidity
• Corrosion

Sustainability

• SF6-free requirement
• Insulation technology
• Environmental documentation

Frequently Asked Questions

What is compact switchgear?

Compact switchgear is electrical switchgear designed to provide switching, protection, isolation, and distribution functions while using installation space efficiently.

What is compact MV switchgear?

Compact MV switchgear is medium-voltage switchgear designed in a space-efficient configuration. It can be used in substations, industrial facilities, renewable-energy projects, data centers, and other MV distribution systems.

What are the advantages of compact switchgear?

The main potential advantages include reduced footprint, efficient equipment layout, suitability for space-constrained installations, and integration of multiple electrical functions into a compact assembly.

Is compact switchgear the same as RMU?

No. An RMU is a specific type of medium-voltage distribution assembly. Compact switchgear is a broader description that can include different switchgear technologies and configurations.

Is compact switchgear suitable for substations?

Yes. Compact switchgear can be used in primary and secondary substations when its electrical ratings, protection, environmental characteristics, and applicable standards meet the project requirements.

Can compact switchgear be used for solar farms?

Yes. Compact MV switchgear can be used for solar collector feeders, transformer connections, auxiliary systems, and grid-related applications.

Can compact switchgear be used for wind farms?

Yes. It can be used in turbine collection systems and wind farm substations where the equipment meets the project’s electrical requirements.

Is compact switchgear suitable for data centers?

Yes. Compact MV switchgear can be considered for data centers where electrical-room space is limited, provided the design meets redundancy, protection, safety, and maintenance requirements.

Is compact switchgear SF6-free?

It can be. Compact switchgear can use vacuum interruption, air insulation, solid insulation, or other technologies. The exact insulation and interruption technology should be verified from the manufacturer’s documentation.

Does compact switchgear require IEC 62271?

The applicable IEC requirements depend on the switchgear type and voltage level. Relevant parts of the IEC 62271 series may apply to medium-voltage switchgear.

Is compact switchgear maintenance-free?

Not automatically. Maintenance requirements depend on the equipment design, technology, operating conditions, manufacturer’s instructions, and application.

How do I choose compact MV switchgear?

Start by defining the voltage, current, fault level, insulation level, panel configuration, protection, environmental conditions, physical space, standards, and project-specific requirements.

Can compact switchgear be customized?

Yes, depending on the manufacturer’s product platform. Possible customization can include panel quantity, feeder arrangement, protection relays, metering, cable entry, dimensions, communication, and other project requirements.

Conclusion

Compact switchgear is designed to provide essential medium- or high-voltage switching and protection functions within an efficient physical configuration.

It can be particularly valuable for projects where installation space is limited, including:

• Secondary substations
• Industrial facilities
• Solar farms
• Wind farms
• Battery energy storage systems
• Data centers
• Urban power distribution

However, the smallest switchgear is not necessarily the best switchgear.

A proper selection should balance footprint, electrical performance, safety, accessibility, maintainability, protection, environmental conditions, standards compliance, and total project requirements.

For MV applications, buyers should carefully evaluate the applicable IEC 62271 requirements and verify the equipment’s voltage, current, short-circuit, insulation, and testing specifications.

If environmental performance is important, SF6-free compact MV switchgear can also be evaluated as an alternative to conventional SF6-based designs, provided the complete equipment meets the project’s technical requirements.