8DA/B 10 With Siemens cooperation download 

Medium Voltage -MV- Switchgear, Gas Insulated, up to 40.5KV Metal-Enclosed, Metal-Clad, Single/Duplicate Busbar


Typical uses
Fixed-mounted circuit-breaker switchgear 8DA and 8DB is indoor, factory-assembled, type-tested, single-pole metal-enclosed, metal-clad, SF6-insulated switchgear for single-busbar and double-busbar applications, as well as for traction power supply systems. It is used in transformer and switching substations, e.g., in:

  • Power supply companies
  • Power stations
  • Cement industry
  • Automobile industry
  • Iron and steel works
  • Rolling mills
  • Mining industry
  • Textile, paper and food industries
  • Chemical industry
  • Petroleum industry
  • Pipeline installations
  • Offshore installations
  • Electrochemical plants
  • Petrochemical plants
  • Shipbuilding industry
  • Diesel power plants
  • Emergency power supply installations
  • Lignite open-cast mines
  • Traction power supply systems.

Technical data

Electrical data

Rated insulation level Rated voltage Ur KV 12 24 36 40.5
Rated short-duration power-frequency
withstand voltage Ud:
  – phase-to-earth, open contact gap KV 28 50 70 85
  – across the isolating distance KV 32 60 80 90
  Rated lightning impulse withstand voltage Up:        
  – phase-to-earth, open contact gap KV 75 125 170 185
  – across the isolating distance KV 85 145 195 220
Rated frequency fr   Hz 50/60 50/60 50/60 50/60
Rated normal current Ir for the busbar A 1250 1250 1250 1250
    A 2000 2000 2000 2000
    A 2500 2500 2500 2500
    A 3150 3150 3150 3150
    A 4000 4000 4000 4000
    A 5000 5000 5000 5000
Rated filling level pre for the busbar 70 – 120 kPa (absolute) at 20 °C
    50 – 100 kPa (absolute) at 20 °C
    – 5 °C to + 55 °C

Design and construction

Design and construction PM (metallic partition)
Partition class LSC 2B
Loss of service continuity category  
Accessibility to compartments (enclosure)  
Busbar compartment Tool-based
Switching device compartment Tool-based
Low-voltage compartment Tool-based
Cable compartment Tool-based

Internal arc classification

Designation of the internal arc
classification IAC IAC class for:
Wall-standing arrangement IAC A FL       40 kA, 1 s
Free-standing arrangement IAC A FLR      40 kA, 1 s
Type of accessibility A Switchgear in closed electrical service location, access
“for authorized personnel only” according to IEC 62271-200
– F Front
– L Lateral
– R Rear (for free-standing arrangement)
Rated short-time withstand current 40KA
Rated duration of short-circuit 1S



Environmental independence

  • The enclosed high-voltage part of 8DA and 8DB switchgear is suitable for applications under aggressive ambient conditions, such as:
    • Saline air
    • Air humidity
    • Dust
    • Condensation.
  • It is tight to ingress of foreign objects, such as:
    • Dust
    • Pollution
    • Small animals.

The application is independent of the site altitude.

Compact design
Thanks to the use of SF6 insulation, compact dimensions are possible.

  • Existing switchgear rooms can be used effectively
  • New constructions cost little
  • Costly city-area space is saved.

Maintenance-free design
Switchgear housings designed as sealed pressure systems, maintenance-free switching devices and enclosed cable plugs ensure:

  • Maximum supply reliability
  • Personnel safety
  • Sealed-for-life design according to IEC 62271-200 (sealed pressure system)
  • Reduced operating costs
  • Cost-efficient investment.

The use of digital secondary systems and combined protection and control devices ensures

  • Clear integration in process control systems
  • Flexible and highly simplified adaptation to new system conditions and thus to cost-efficient operation.

Service life
Under normal operating conditions, the expected service life of gas-insulated switchgear 8DA and 8DB is at least 35 years, probably 40 to 50 years, taking the tightness of the enclosed high voltage part into account. The service life is limited by the maximum number of operating cycles of the switching devices installed:

  • For circuit-breakers, according to the endurance class defined in IEC 62271-100
  • For three-position disconnectors and earthing switches, according to the endurance class defined in IEC 62271-102.


Personal safety

  • Safe-to-touch and hermetically sealed primary enclosure
  • All high-voltage parts including the cable terminations, busbars and voltage transformers are metal-enclosed
  • Capacitive voltage detecting system to verify safe isolation from supply
  • Operating mechanisms and auxiliary switches safely accessible outside the primary enclosure (switchgear housings)
  • Due to the system design, operation is only possible with closed switchgear enclosure
  • Standard degree of protection IP 65 for all high-voltage parts of the primary circuit, IP 3XD for the switchgear enclosure according to IEC 60529 and VDE 0470-1
  • High resistance to internal arcs by logical mechanical interlocks and tested switchgear enclosure
  • Panels tested for resistance to internal faults up to 40 kA
  • Logical mechanical interlocks prevent maloperation
  • Make-proof earthing by means of the vacuum circuit-breaker.

Security of operation

  • Hermetically sealed primary enclosure independent of environmental effects (pollution, humidity and small animals)
  • Maintenance-free in an indoor environment according to IEC 62271-1 and VDE 0671-1
  • Two-phase and three-phase short-circuits between the primary conductors are excluded by the single-pole primary enclosure.
  • In isolated or compensated systems, low-current earth-fault currents are self-extinguishing
  • Operating mechanisms of switching devices accessible outside the primary enclosure (switchgear housings)
  • Metal-enclosed, plug-in inductive voltage transformers mounted outside the SF6 switchgear housing
  • Current transformers as ring-core current transformers mounted outside the SF6 switchgear housings
  • Complete switchgear interlocking system with logical mechanical interlocks
  • Bolted switchgear housings sealed for life
  • Minimum fire load
  • Option: A seismic design.


  • Type and routine-tested
  • Standardized, NC production processes
  • Quality assurance in accordance with DIN EN ISO 9001
  • More than 500,000 switchgear panels of Siemens in operation worldwide for many years.



  • Single-pole enclosure of the primary part by modular switchgear housings made of corrosion-resistant aluminum alloy
  • Insulating gas SF6
  • Three-position disconnector as busbar disconnector and feeder earthing switch
  • Make-proof earthing by means of the vacuum circuit-breaker
  • Compact dimensions due to SF6 insulation
  • Hermetically bolted switchgear housings made of corrosion resistant aluminum alloy
  • Single-pole metal-enclosed, SF6-insulated busbars
  • Cable connection with inside-cone plug-in system, or for connection of gas-insulated and solid-insulated bars
  • Wall-standing or free-standing arrangement
  • Installation and extension of existing switchgear at both ends without modification of existing panels.


  • According to IEC 62271-200 and VDE 0671-200
  • Logical mechanical interlocks prevent maloperation
  • Three-position disconnector can only be operated with circuit-breaker in OPEN position
  • Circuit-breaker can only be operated with three-position disconnector in end position and operating lever removed
  • Locking device for circuit-breaker
  • Locking device for three-position disconnector
  • “Feeder earthed” locking device
  • Option: Electromagnetic interlocks
  • Option: Actuating openings can be padlocked.

Modular design

  • Replacement of the panel connection housings or the circuit breaker possible without interrupting busbar operation.]
  • Low-voltage compartment removable, plug-in bus wires.
  • Extension of double-busbar switchgear 8DB10 possible without interrupting operation.
  • Option: Extension of single-busbar switchgear 8DA10 possible without interrupting operation.

Instrument transformers

  • Current transformers not subjected to dielectric stress
  • Metal-enclosed, plug-in and disconnectable voltage transformers.

Vacuum circuit-breaker

  • Maintenance-free under normal ambient conditions according to IEC 62271-1 and VDE 0671-1
  • No republication or readjustment
  • Vacuum interrupters sealed for life
  • Up to 10,000 operating cycles (maintenance-free)
  • Option: Up to 30,000 operating cycles (maintenance required).

Secondary systems

  • Customary protection, measuring and control equipment
  • Option: Numerical multifunction protection relay with integrated protection, control, communication, operating and monitoring functions
  • Can be integrated in process control systems.


تماس با ما

دفتر مرکزی(تهران):
تهران، خیابان تهران- بلوار افريقا- نرسيده به چهارراه جهان کودک- کوچه کمان- شماره 24  ساختمان کویر
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