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.
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.
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.
Technical specifications
| Rated voltage | 12 | 17.5 | 24 | |
| Impulse withstand voltage 1.2 / 50 μs: | ||||
| - To earth and between phases | kV | 75 | 95 | 125 |
| - Over the insulated distance | kV | 85 | 110 | 145 |
| Power frequency withstand voltage: | ||||
| - To earth and between phases | kV | 28 | 38 | 50 |
| - Over the insulated distance | kV | 32 | 45 | 60 |
| Rated frequency | Hz | 50/60 | 50/60 | 50/60 |
| Rated current | A | 630 | 630 | 630 |
| Rated short-time current 1s | k | 20 | 20 | 20 |
| Rated peak value of the current | k | 50 | 50 | 50 |
| Breaking capacity RV53 (class E3): | ||||
| - Mainly active load (I1 / Iloop) | A | 630 | 630 | 630 |
| - Closed loop current (I2A / Iloop) | A | 630 | 630 | 630 |
| - Cable charging current (I4A/ICC) | A | 16 | 16 | 16 |
| - Cable charging current (0,2-0,4 I4A / 0,1-0,4 ICC) | A | 5 | 5 | 5 |
| - Short circuit making current (Ina) | k | 50 | 50 | 50 |
| - Earth fault current (I6a/Ief1) | A | 100 | 100 | 100 |
| - Cable and line charging current under earth faults (I6b / Ief2) | A | 30 | 30 | 30 |
| Degree of protection | IP4X | IP4X | IP4X | |
| Mechanical durability c/o | 1000 | 1000 | 1000 | |
| 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
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
DF-2 projects
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Meet the experts of SGC at SEPEM Toulouse and pay us a visit at booth A19!
Partnership development with Philippine delegation at SGC
It's already the second time this year that we've had the honor of welcoming the Ambassador and the…
Successful collaboration: Finexpo and CIE
Last week, we had the pleasure of welcoming Finexpo and COMPAGNIE IVOIRIENNE D’ÉLECTRICITÉ to SGC -…
SGC at SEPEM Industries Toulouse
Meet the experts of SGC at SEPEM Toulouse and pay us a visit at booth A19!
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