24kV Indoor Disconnect Switch with Earthing Switch

Dongfa Intelligent's GN30-24D series is a 24kV Indoor Disconnect Switch with Earthing Switch that integrates both functions on a single base, available in four current ratings: 400A, 630A, 1000A, and 1250A. Thermal stability current ranges from 12.5kA to 31.5kA (4s), dynamic stability current from 31.5kA to 80kA, and the insulation level is 42kV power-frequency withstand and 75kV impulse withstand. The product is supported by Dongfa Intelligent's 14 years of high-voltage electrical manufacturing experience, with CNAS/IAF recognized testing capability. Monthly capacity is 600-700 units, annual capacity is 7,000-8,000 units, and products have been exported to Southeast Asia and parts of Europe.

Key Features

Integrated Isolation and Earthing

The disconnecter and earthing switch are integrated on the same base, reducing the interlocking links required when a separate earthing switch is used. The disconnecter and the earthing switch are linked by a mechanical interlocking mechanism with the following logic:

• The earthing switch can only be closed after the disconnecter is opened.
• The disconnecter cannot be closed after the earthing switch is closed.
• The disconnecter can only be closed after the earthing switch is opened.

This prevents the disconnecter from being earthed while energized. Switchgear builders should confirm the interlocking requirement during the design phase; the interface and operating stroke of the interlocking mechanism are confirmed based on the cabinet structure.

Four Current Ratings

400A, 630A, 1000A, and 1250A, with thermal stability current from 12.5kA to 31.5kA and dynamic stability current from 31.5kA to 80kA, covering common 24kV system configurations.

High Insulation Level

42kV power-frequency withstand and 75kV impulse withstand, meeting insulation coordination requirements for 24kV indoor systems.

Compliance

Compliant with GB standards and IEC 62271.

Customization

Operating mechanisms differ between switchgear manufacturers. The interface between the interlocking mechanism and the operating panel can be adjusted according to the cabinet design. During inquiry, provide your interlocking logic requirements or cabinet drawings. A technical review is conducted before production to confirm assembly and linkage.

Total Cost of Ownership

24kV Indoor Disconnect Switch with Earthing Switchs are evaluated over a 5-10 year service life. The following cost items are considered:

• Initial procurement cost: direct supply from the manufacturer.
• Maintenance cost: the product uses anti-corrosion contacts and standard insulation materials; maintenance intervals depend on service conditions.
• Spare parts and after-sales cost: original spare parts supplied by the factory.
• Risk cost: unplanned outages interrupt production and may cause safety incidents.

24kV disconnectors are commonly used in main incoming and bus-tie circuits, where downtime is costly.

Technical Specifications

The GN30-24D series 24kV Indoor Disconnect Switch with Earthing Switch is available in four ratings:

Parameters to Confirm

• Rated voltage: 24kV.
• Rated current: 400A / 630A / 1000A / 1250A, depending on circuit load.
• Thermal stability current: 12.5kA / 20kA / 31.5kA (4s), matched to system short-circuit capacity.
• Dynamic stability current: 31.5kA / 50kA / 80kA, matched to system peak short-circuit current.
• Insulation level: 42kV power-frequency withstand, 75kV impulse withstand.
• Earthing switch interlocking: confirm earthing position, operating method, and interlocking with the circuit breaker.
• Installation dimensions: mounting hole distances and terminal arrangements differ between 400A/630A, 1000A, and 1250A.

Information for Replacement Projects

To confirm compatibility, provide: original disconnector model, switchgear drawings, mounting dimensions, rated current, thermal/dynamic stability requirements, earthing interlocking requirements, and quantity. Original drawings or clear photos with measurement data can also be used as reference.

Delivery and Testing

Standard products: 7-15 working days. Custom products: 15-30 working days. Standard products support a 1-unit trial order. Each unit passes resistance test, mechanical operation test, withstand voltage test, and vacuum degree inspection before shipment.

Company Information

Zhejiang Dongfa Intelligent Electric Technology Co., Ltd. was founded in 2012 and has 14 years of experience in high-voltage electrical manufacturing.

The factory is located in Yueqing Economic Development Zone, Wenzhou, Zhejiang, covering over 2,000m², with 17 employees, 4 technical engineers, 2 production lines, and 1 set of testing equipment. Monthly capacity is 600-700 units; annual capacity is 7,000-8,000 units. Products have been exported to Southeast Asia and parts of Europe.

During the technical confirmation stage, a 1-on-1 drawing review is provided to check A, B, C dimensions, mounting hole distances, and interlocking interfaces against the switchgear design. Technical questions are answered within 1 working day.

Semi-finished products and components are kept in stock to respond to urgent orders.

Certifications: ISO 9001, ISO 14001, ISO 45001. Testing capability is CNAS/IAF recognized. Core products come with type test reports. Factory audits are supported.

FAQ

Q1: What is the main difference between the 24kV Indoor Disconnect Switch with Earthing Switch and one without?

A: A disconnector without an earthing switch only provides isolation; a separate earthing switch is needed during maintenance. A disconnector with an earthing switch (like GN30-24D) integrates the earthing function on the same base. The integrated design makes it easier to implement the interlocking logic of "open first, earth second."

Q2: How is the interlocking between the earthing switch and disconnector achieved? Can it be customized?

A: It is achieved through a mechanical interlocking mechanism. Typically, the earthing switch can only be closed after the disconnector is opened, and the disconnector cannot be closed after the earthing switch is closed. The mechanism can be adjusted to different cabinet structures and operating panels. Please provide interlocking logic requirements or cabinet drawings during inquiry.

Q3: How to choose between 12.5kA, 20kA, and 31.5kA?

A: Selection depends on system short-circuit capacity. 12.5kA is used for smaller-capacity feeder cabinets, 20kA for medium-capacity distribution, and 31.5kA for main transformer incoming cabinets or large-capacity systems. Please provide the system short-circuit current calculation values during selection.

Q4: Why are installation dimensions different for 400A/630A and 1000A/1250A?

A: Different current ratings require different conductive circuit cross-sectional areas and insulation distances, so mounting hole distances and terminal dimensions differ. 400A/630A share one mounting hole distance; 1000A uses 4-Φ13 (40×80mm spacing); 1250A uses 4-Φ13 (60×100mm spacing). Refer to the corresponding model drawing for specific dimensions.

Q5: What information is needed for replacement projects?

A: Please provide the original disconnecter model, switchgear drawings, mounting dimensions, rated current, thermal/dynamic stability requirements, earthing interlocking requirements, and quantity. Original drawings or clear photos with measurement data can also be used as reference.

Q6: Are you a factory or a trader? Do you support factory audits?

A: The 24kV Indoor Disconnecter with Earthing Switch is manufactured by Dongfa Intelligent, which operates a 2,000+ m² factory in Yueqing, Zhejiang, founded in 2012 with 14 years of manufacturing experience. Factory audits are supported. You are welcome to visit.

Contact

To request a quotation, provide: rated current, thermal/dynamic stability requirements, earthing interlocking requirements, installation dimensions, and quantity.

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