Air insulated switchgear

High-quality and compact air insulated switchgear: DF-3(+)

We engineer reliable switchgear built on safety and durability

Our most compact product: the “DF-3”, is a metal-clad and high-quality AIS switchgear solution. A modular concept combining all medium voltage functions. Therefore, we provide made-to-measure solutions for all your medium voltage needs.

Request an offer

Modular design

3-position load break switch

Arc-killer option

The DF-3 system is a modular concept based on the “building blocks” principle, which means that cubicles are produced in series. As a result, the modular DF-3 concept meets the highest technical standards in a rational, economically sound way. The combination of cubicles is unlimited. The cubicle dimensions are very dense since the switching occurs in an SF6 insulation medium. The semi-compact cubicles are particularly beneficial if the available space should pose a problem or if economical factors play an important role. You get the benefits of the DF-2, with more compact dimensions (DF-3: 1400mm x 375mm vs DF-2: 1700mm x 500mm). Our AIS solutions are always extendable, compartmentalized and can handle up to 24 kV.

SGC offers a wide range of applications with the DF-3 cubicles and associated air insulated switchgear solutions. They can be used worldwide in many industries. DF-3 cubicles are compact, so you can combine several cubicles in tight spaces. Cubicles contain all functional interlocks which allows for effortless application, according to all current standards, which allows installation in consumer work spaces. As a result, capacity loss will be minimal. 

For all your needs and demands, the DF-3 cubicles and associated air insulated switchgear provide a solution: it can replace obsolete installations and extend existing installations, and it is also perfectly suitable for entirely new constructions. The DF-3 is designed to withstand extreme conditions, maximize the switchboard’s life and ensure the operator’s safety.

Modular air insulated switchgear: The DF-3 system

  • Air Insulated Switchgear: metal enclosed AIS cubicles with galvanized steel sheets 1mm and 2mm between the compartments 
  • Modular system – compact - combination is unlimited
  • High operator safety
  • Remote control operation or manual/automatic
  • Switching in SF6 for switch or vacuum circuit breaker
  • Stand alone cubicles – high continuity
  • Can be equipped with a wide range of optional features

In contrast to the popular model DF-2, the DF-3 is equipped with a three-position load break switch RV-53 (on/off/earth). These switches are “sealed for life” and require minimal maintenance. It also comes with an integrated earthing switch in the body of the load break switch. The modular copper busbar can withstand a pressure of 630A. The smart modular design of the DF-3 allows you to create rational, economical and custom-made combinations of medium voltage cubicles (with rated voltage of 12, 17,5 or 24kV). The DF-3 cubicle also comes with interlocked, removable doors. The optional padlocks prevent unauthorized access.

Our medium voltage cubicles are much more environmentally friendly. SF6 is only used in the load break switch, which means the use of a minimal amount of SF6.

Internal arc resistance

The DF-3 is designed to resist internal arcs, protecting both the operator and the installation. Through a strategic pressure release system, the internal arc is restricted to the compartment where it originated, and it does not propagate towards the operator or to other compartments. An internal arc is created by a short-circuit or another malfunction. In a classic MV cubicle, an internal arc could severely damage the installation and possibly injure the operator and electrocute them. SGC aims to protect its users and operators, thanks to the built-in ARC-killers.

The anti-arc kit of DF-3 cubicles is specifically designed to minimize the consequences of an internal arc. By default, all provided cubicles are fitted on the rear side with overpressure valves pointing downward.  The DF-3 cubicles were tested at KEMA IAC (AFL) FOR 14 kA/1s as well at a rated voltage of 17,5 kV/24kV according to IEC 62271-200. Consequently, all SGC – SwitchGear Company cubicles are internal arc resistant.

Discover Arc-killer

Our DF-3 AIS product line

Discover the product that’s right for you. At SGC, we  are here to help you choose the best solution. 

The DF-3 range is specifically designed to fit in smaller, tighter spaces. Therefore, it’s hugely versatile and profits from compact dimensions. It’s built to last: all components are robust and of the highest quality. SGC is a preferred partner thanks to the guaranteed operator safety, co-engineering and long-lasting quality.

Want the top of the range with built-in ARC-killer? Then is the DF-3+ the ultimate option for you. The DF-3+ includes the arc-killer SV-35, a system for detecting and extinguishing an internal arc. The arc-killer extinguishes the arc by directing it to a metal earthed short circuit. The arc is extinguished in less than 50 ms.

A DF-3+ is a metal-enclosed cubicle of the DF-3 type combined with a duct  at the rear of the cubicle. The duct absorbs the gasses (in case of an internal arc) that escape through the overpressure valves. As a result, the expansion of hot gasses in a room can be reduced to an absolute minimum.

Want more information? Our team is here to help.

Contact us today

Technical specifications

Rated voltage1217.524
Impulse withstand voltage 1.2 / 50 μs:
- To earth and between phaseskV7595125
- Over the insulated distancekV85110145
Power frequency withstand voltage:
- To earth and between phaseskV283850
- Over the insulated distancekV324560
Rated frequencyHz50/6050/6050/60
Rated currentA630630630
Rated short-time current 1s202020
Rated peak value of the current505050
Breaking capacity RV53 (class E3):
- Mainly active load (I1 / Iloop)A630630630
- Closed loop current (I2A / Iloop)A630630630
- Cable charging current (I4A/ICC)A161616
- Cable charging current (0,2-0,4 I4A / 0,1-0,4 ICC)A555
- Short circuit making current (Ina)505050
- Earth fault current (I6a/Ief1)A100100100
- Cable and line charging current under earth faults (I6b / Ief2)A303030
Degree of protectionIP4XIP4XIP4X
Mechanical durability c/o100010001000
Standards: IEC 62271-100, IEC 62271-1, 62271-102, -103, -105, 62271-200 and IEC 61243-5
Certificats: KEMA/IPH

(*) According to IEC 62271-103, class E1 / (**) Option Arc-killer

Download our complete DF-3 catalogue

Our DF-3 cubicles can be used in a wide range of configurations

DF-A

Incoming cubicle or cable field with load break switch and interlocked earthing switch


DF-P

Transformer protection cubicle with load break switch/fuse combination


DF-C-750

Metering cubicle


DF-K

Cable cubicle and/or rail shaft

Discover more and other configurations

DF-2 projects

Cabling via 3D engineering

Turnkey cabling with 3D design software

Optimizing production processes with our cable machine, an automation solution for wire assembly.

Read More

Delivery of DF-2 station for Moundou in Chad.

For a substation of SNE in Chad, contractor Deba opted for SGC’s DF-2 program.

Read More

New exclusive distributor of Switchgear Company in Vietnam

We are proud to confirm that Asia Technology and Energy System Co. Ltd is the official dealer of…

Read More

Cabling via 3D engineering

Turnkey cabling with 3D design software

Optimizing production processes with our cable machine, an automation solution for wire assembly.

Read More

Delivery of DF-2 station for Moundou in Chad.

For a substation of SNE in Chad, contractor Deba opted for SGC’s DF-2 program.

Read More

New exclusive distributor of Switchgear Company in Vietnam

We are proud to confirm that Asia Technology and Energy System Co. Ltd is the official dealer of…

Read More

More news

Subscribe to our newsletter

Other SGC solutions

AIS

Air insulated switchgear

  • Always extendible
  • Minimal amount of SF6 (LBS)
  • Switchgear is compartmentalized
  • Withdrawable circuit breaker
  • 12 kV – 17,5 kV –  24 kV

GIS

Gas insulated switchgear

  • Ring main unit
  • Gas insulated
  • Compact monobloc
  • Lateral extension is optional
  • 12 kV – 17,5 kV – 24 kV – 36 kV 

HYBRID

Hybrid switchgear

  • Always extendible
  • Air insulation + minimal amount of SF6
  • Switchgear is compartmentalized
  • Withdrawable circuit breaker
  • 12 kV – 17,5 kV – 24 kV 

We excell in co-engineering 
made to measure solutions

Innovation and environmental care are the driving forces behind our products and company. A lot of our products are developed from co-engineering with clients, supplying solutions that fit their needs and specifications.

Contact our engineers

Explore our Sahel-line

A complete line of high quality products, built to withstand the extreme conditions in the coastal regions.

DISCOVER OUR SAHEL-LINE

Explore our Extreme-line

A complete line of high quality products, built to withstand the extreme conditions of freezing temperatures.

DISCOVER OUR XTREME-LINE

Our SwitchGear projects worldwide...