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, arc-resistant switchgear for critical power applications

That offers reduced maintenance, enhanced operator safety, compact footprint, and is environmentally independent

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.

8DA10 and 8DB10 gas-insulated switchgear overview

Medium-voltage, gas-insulated switchgear overview

Features

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.

Accessories

Standard accessory:

Manual operation tool kit.

Optional accessory:

Human Machine Interface (HMI).

Ratings

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
15.5	Up to 40	Up to 40	5,000	3,000 (8DA)/2,500 (8DB)	36	95	Up to 104	Up to 104
27.0	Up to 40	Up to 40	5,000	3,000 (8DA)/2,500 (8DB)	60	125	Up to 104	Up to 104
38.0	Up to 40	Up to 40	5,000	3,000 (8DA)/2,500 (8DB)	80	150, 200¹	Up to 104	Up to 104
42.0¹	Up to 40	Up to 40	5,000	3,000 (8DA)/2,500 (8DB)	80	185, 200¹	Up to 104	Up to 104

Footnotes:

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

Dimensions in inches (mm)
Type	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)

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TechTopics is a series of papers that discuss issues of interest to users or specifiers of electrical equipment.

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).

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