Indoor High Voltage Disconnect Switches for 12kV Switchgear

Fenarro indoor high voltage disconnect switches provide a clearly identifiable isolation point for high-voltage circuits installed in enclosed electrical systems.
Designed for integration into 12kV switchgear and indoor power distribution equipment, our disconnectors feature a compact structure, dependable contact performance and flexible installation configurations. They are suitable for indoor substations, distribution rooms, industrial facilities and infrastructure projects where electrical equipment must be safely isolated before inspection or maintenance.

Download

Indoor High Voltage Disconnect Switch Series

What Is an Indoor High Voltage Disconnect Switch?

An indoor high voltage disconnect switch, also known as an indoor HV disconnector or indoor high voltage isolator, is used to create a clearly identifiable isolation point in an electrical circuit. The device is normally installed inside medium-voltage switchgear,distribution cabinets or indoor substations. Its primary purpose is to isolatebusbars, incoming feeders, transformers or other electrical equipment afterthe operating current has already been interrupted.

Unlike a circuit breaker, a conventional indoor disconnector is not designed tointerrupt normal load current or short-circuit current. It is normally operatedtogether with a circuit breaker and, where required, an earthing switch.
For a detailed explanation of its function and operating limitations, read:
Systems High Voltage Disconnect Switch Explained: Safe Isolation for Power

Key Features of Indoor High Voltage Disconnect Switches Reliable Visible Isolation

Reliable Visible Isolation

Clear open and closed positions
Safe isolation point for maintenance
Stable contact performance
Designed for no-load switching

Compact Switchgear Integration

Compact indoor structure
Suitable for 12kV power systems
Flexible installation arrangements
Designed for enclosed switchgear

Flexible Safety Options

Operating mechanism options
Optional earthing switch

Mechanical interlocking available
Switchgear system compatibility

Rated Voltage System voltage and insulation coordination View More

The rated voltage must match the system voltage and required insulation level. For example, a 12kV disconnector is typically used in a 10kV medium-voltage distribution system.

Rated Current Continuous current-carrying capability View More

Rated current defines the continuous current the disconnect switch can safely carry. It should be selected according to the busbar or feeder load requirements.

Short-Time Withstand Current Thermal withstand capability during faults View More

Although the disconnector does not interrupt fault current, it must withstand the associated thermal and mechanical stresses until the upstream protection device clears the fault.

Peak Withstand Current Resistance to peak electrodynamic forces View More

Peak withstand current indicates the ability of the closed disconnector to resist electrodynamic forces generated under short-circuit conditions .

Insulation Level Power-frequency and lightning-impulse withstand View More

The insulation level includes the required power-frequency and lightning-impulse withstand values. It must comply with the insulation coordination of the switchgear system.

Phase Spacing Cabinet layout and electrical clearance View More

Pole and phase spacing must fit the switchgear layout while maintaining sufficient electrical clearance and safety distance.

Operating Mechanism Operating direction, linkage and cabinet compatibility View More

The operating direction, linkage type and mechanical structure must be fully compatible with the switchgear cabinet design.

Earthing & Interlocking Earthing configuration and operating-sequence control View More

Confirm whether an earthing switch is required and how the interlocking system should coordinate with:

The circuit breaker
The earthing switch
The switchgear cabinet door

Selection support: Providing a switchgear drawing or single-line diagram helps the engineering team verify electrical parameters, installation dimensions and mechanical compatibility.

Application Scenarios

Indoor Distribution Substations

Suitable for 12kV indoor substations, where disconnect switches provide visible isolation for busbars, incoming feeders and other high-voltage equipment before inspection or maintenance.

Medium-Voltage Switchgear

Designed for integration into enclosed switchgear assemblies to isolate designated sections of the main circuit after the operating current has been interrupted.

Industrial Power Distribution

Applicable to factories, mines, processing plants and other industrial facilities requiring dependable isolation of transformers, feeders and electrical equipment.

Commercial/Infrastructure Facilities

Suitable for power distribution rooms in commercial buildings, transport facilities and infrastructure projects where compact installation and safe maintenance isolation are required.

Indoor Disconnector vs Circuit Breaker vs Load Break Switch

These three devices perform different functions and should not be treated as interchangeable.

Feature	Indoor Disconnect Switch	Vacuum Circuit Breaker	Load Break Switch
Primary Function	Visible circuit isolation	Circuit protection and current interruption	Normal load switching
Interrupts Load Current	No	Yes	Yes, within its rated capability
Interrupts Short-Circuit Current	No	Yes	Normally requires a fuse or upstream protection
Identifiable Isolation Position	Yes	Not always externally visible	Depends on the design
Typical Application	Maintenance isolation	Feeder and equipment protection	Distribution switching
Common Installation	Indoor switchgear	Indoor switchgear	Ring main units and distribution switchgear

Important: A disconnect switch cannot replace a circuit breaker. The circuit breaker interrupts operating or fault current, while the disconnector establishes the isolation point required for safe maintenance.

Learn More： HV Disconnect Switch vs Circuit Breaker

Ready to Specify Your Indoor High Voltage Disconnect Switch?

Contact Fenarro’s engineering team for product selection support based on your system voltage, rated current, switchgear layout, earthing requirements and operating mechanism. Send us your single-line diagram, switchgear drawing or required technical parameters to receive configuration support, technical documentation, pricing and estimated delivery information.

Get your quote now!

FAQs About Indoor High Voltage Disconnect Switches

Q Do you provide grounding switches?

A Yes, we offer both single and double grounding blade options for all models.
Q What is the typical delivery time for disconnect switches?

A Standard products: 8-12 weeks; Custom configurations: 12-16 weeks
Q Can your disconnectors be motorized for remote operation?

A Yes, we offer motorized versions for all models with remote control capability.
Q What is the difference between disconnect switches and circuit breakers?

A Disconnect switches provide visible isolation for maintenance but cannot interrupt load current, while circuit breakers can interrupt fault currents.
Q How to confirm payment?

A We accept payment methods such as wire transfer and PayPal. Other payment methods are also acceptable, please contact us before making payment through other methods. Additionally, a 30% deposit is feasible, and the balance should be paid before shipment.

Related Proudcts

FGN19-12 Series Indoor HV Disconnector

ZCW10-40.5 Series Open Combination Electrical Appliances

FZCW10-40.5G Air Insulated Switchgear (AIS)

FZW32-12 & FZW32-40.5 Outdoor HV Isolating-Load Switch Combo

Indoor High Voltage Disconnect Switches for 12kV Switchgear

Indoor High Voltage Disconnect Switch Series

What Is an Indoor High Voltage Disconnect Switch?

Key Features of Indoor High Voltage Disconnect Switches Reliable Visible Isolation

Technical Parameters to Consider