8DA10 single-bus and 8DB10 double-bus, arc-resistant to IEEE C37.20.7 type 2B, gas-insulated switchgear

8DA10 single-bus arc-resistant gas-insulated switchgear

15-38 kV
  • Rated short-time withstand current up to 40 kA

  • Rated continuous current of circuit breakers up to 5,000 A

  • Lightning impulse (BIL) up to 200 kV

Gas-insulated, medium-voltage, arc-resistant switchgear

Medium-voltage (MV) gas-insulated switchgear (GIS) types 8DA10 and 8DB10 are gas-insulated, vacuum circuit breaker designs with a maximum design voltage of 4.16 kV up to 38 kV (42 kV on request). Lightning impulse-withstand voltage ratings up to 200 kV BIL and interrupting ratings up to 40 kA are available.

The types 8DA10 and 8DB10 MV GIS designs feature fixed-mounted vacuum circuit breakers, connectable to the main bus through three-position (CLOSED-OPEN-READY TO GROUND) switches. The position of the switches is indicated by reliable contact position indicators and can also be visibly verified from the front of the unit using a convenient camera system and laptop computer. Complies with NEC visible disconnect requirement NEC 225.1 and 230.204.


MV GIS is approximately 75% smaller than conventional air-insulated switchgear depending upon the voltage rating and is suitable for systems where small size, arc resistance, environmental immunity and/or reduced maintenance needs are important.



Watch the video below to learn more about medium-voltage, gas-insulated, arc-resistant switchgear.


Features include:


  • Arc-resistant to IEEE C37.20.7, up to 40 kA, 0.5 sec, accessibility type 2B
  • Significantly reduced personal protective equipment (PPE) needs
  • Single-phase design eliminates phase-to-phase faults insided the switchgear
  • Vacuum interrupter - up to 30,000 mechanical operations
  • Low-pressure SF6 gas-insulated for insulation only and not for interruption
  • Voltage transformers with primary fused protection per NEC article 240.15(A) and 450.3(C)
  • Main busbar expansion without shutdown via optional busbar expansion switch
  • Compact - up to 75 percent smaller than traditional air-insulated switchgear
  • Maintenance-free primary part
  • Well-suited for contaminated environments
  • Pair with Siemens protective relays to match any typical application
  • Over 130,000 panels worldwide with more than 5,300 installed in North America
  • Meets NEC visible disconnect requirement
  • Meets or exceeds the latest IEEE and IEC standards
  • UL or C-UL Listing available.


Types 8DA10 and 8DAB10 switchgear available as:

  • Indoor.



Standard accessory:

  • Manual operation tool kit.


Optional accessory:

  • Human Machine Interface (HMI).




Maximum design voltage kV
Rated interrupting rating kA
Maximum interrupting and short time kA
Continuous current of main bus (maximum)
Continuous current of circuit breakers (maximum)
Withstand voltage levels - power frequency kV rms
Withstand voltage levels - lightning impulse (BIL) kV peak
Closing and latching short-circuit making current  kA peak
Closing and latching peak withstand current kA peak
Up to 40
Up to 40
3,000 (8DA)/2,500 (8DB)
Up to 104
Up to 104
Up to 40
Up to 40
3,000 (8DA)/2,500 (8DB)
Up to 104
Up to 104
Up to 40
Up to 40
3,000 (8DA)/2,500 (8DB)
150, 2001
Up to 104
Up to 104
Up to 40
Up to 40
3,000 (8DA)/2,500 (8DB)
185, 2001
Up to 104
Up to 104


1 On request. Consult factory.

2 Tested to ANSI/IEEE C37.20.7-2007 for arc-resistance type 2B at 40 kA for 0.5 seconds.


Dimensions in inches (mm)
Height (H)
Width (W)
Depth (D)
Indoor 8DA10
106.3 (2,700)
23.6 (600)
64.0 (1,625)
Indoor 8DB10
106.3 (2,700)
23.6 (600)
105.0 (2,665)
Type 8DA and Type 8DB dimensions graphic

Q: Can the circuit breaker interrupt if there is a leak and no SF6 gas is available?

A: Yes, the vacuum interrupters are independent of the SF6 gas and all the interruption occurs inside the vacuum interrupters. SF6 gas is only used for insulation.


Q: What is the probability of SF6 leakage?

A: The low leakage rate is possible as the normal pressure is 1.5 bar (22 psig) or less, as the SF6 gas is used only for insulation, not for interruption.


Q: What is medium-voltage gas-insulated switchgear?


  • Vacuum interruption technology with SF6 as an insulation medium

  • Over 1,000,000 Siemens vacuum interrupters manufactured. Circuit breakers are fixed mounted, which reduces floor space requirements and eliminates complexities of drawout construction.

  • Three-position selector switch allows extra security for isolation of load side during maintenance

  • Single-phase encapsulated, thus eliminating phase-to-phase faults

  • Enclosures are safe-to-touch from busbar housing to primary cables

  • Capacitive voltage indicators allow extra security for detection of voltage presence before performing maintenance

  • High-voltage components are encapsulated in SF6

  • All low-voltage components are installed outside of SF6

  • Current transformers (CTs) are outside of the high-voltage enclosure and thus not exposed to dielectric or thermal stress

  • Pressure gauges monitor SF6 compartments and contacts are available for sending alarm signals to SCADA system or annunciator

  • Gas leakage less than 0.1% per compartment per year

  • Arc-resistant design

  • More compact than conventional air-insulated switchgear - up to 75% smaller depending upon voltage rating

  • Available in single (type 8DA10) and double (type 8DB10) busbar designs

  • Seismic capability up to UBC zone 4 (optional).


Q: When should medium-voltage, gas-insulated switchgear be used?


  • Ratings - up to 38 kV (42 kV on request), 2,500 A, 40 kA and 200 kV BIL

  • Reliability - virtually maintenance-free with recommended minor maintenance at 10-year intervals and major maintenance at 20-year intervals. Vacuum interrupter endurance is 30,000 mechanical operations.

  • Personnel security - MV GIS is an arc-resistant design design and is safe-to-touch from the busbar compartment to the power cables. All operations are performed in front of the switchgear.

  • Space savings - MV GIS is up to 75% smaller than conventional air-insulated switchgear depending upon the voltage rating that could result in a total cost saving in land and buildings. 

  • Environmental problems - MV GIS is perfect for installation sites with dust, vermin, salt or a contaminated atmosphere. Available for installation in an outdoor power equipment center (PEC).

  • Altitude - MV GIS is insulated with SF6 instead of air and therefore is not required to be derated.

  • Flexibility - MV GIS can be customized to your needs. MV GIS is available in single-bus (type 8DA10) and a double-bus (type 8DB10) designs.

  • Grounding - MV GIS has grounding capabilities for both the power cables (standard) and the busbars (optional).

Mailing address

Siemens Industry, Inc.

7000 Siemens Road

Wendell, North Carolina 27591

United States

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