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Medium-Voltage Metal-Clad Non-Arc-Resistant Switchgear

Type GM-SG (5 kV - 15 kV)

Features and Benefits

Aisle-Less Non-Walk-In OGM-SG Medium-Voltage Switchgear

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Siemens type GM-SG 5 kV, 7.2 kV and 15 kV metal-clad power switchgear assemblies with horizontal drawout type GMSG vacuum circuit breakers take advantage of the latest developments in vacuum interrupter technology. Up to two circuit breakers can be stacked in a single vertical section, allowing significant space savings.

The equipment meets or exceeds the latest standards of ANSI, IEEE and NEMA.

Type GM-SG switchgear is designed for use in industrial plants, commercial buildings, electric utility systems, cogeneration installations and other electrical systems. It is commonly used for protection and switching of transformers, motors, generators, capacitors, buses, distribution feeder lines and, in general, for protection of any medium-voltage power circuit.

Siemens experience gained in over 80 years of supplying metal-clad switchgear in the U.S. has been captured in the type GM-SG design. The objective has been to incorporate features designed to provide safety, while simplifying operation, maintenance and minimizing installation cost.

The switchgear structure and the drawout vacuum circuit breaker are an integrated design, with dielectric, thermal and interruption integrity built directly into the basic design, not as an afterthought.

Siemens Integrated Electric-Racking System (SIERS) is optionally available with type GM-SG switchgear.

Type GM-SG Medium-Voltage Metal-Clad Non-Arc-Resistant Switchgear

Type GM-SG Medium-Voltage Metal-Clad Non-Arc-Resistant Switchgear
Type SGM-SG Medium-Voltage Metal-Clad Non-Arc-Resistant Switchgear Factory Insulated and Assembled Aisle (Optional)


Features include:

  • One-high or two-high construction

  • Up to 100 full-fault interruptions

  • Universal spare circuit breaker for 50 kA and lower ratings

  • Universal spare circuit breaker for 63 kA ratings

  • Interlocks permit insertion of higher rating vacuum circuit breaker into lower rated cell but not vice versa

  • Front accessible circuit breaker operating mechanism for ease of maintenance

  • Closed door racking

  • Floor rollout circuit breaker in lower cell without a dolly

  • Visible secondary disconnect

  • Circuit breaker ships inside of cell, thus reducing installation cost and transit damage

  • Pair with Siemens protective relays to match any typical application

  • Horizontal drawout type GMSG vacuum circuit breaker with type 3AH3 operating mechanism

  • Uses the latest developments in vacuum interrupter technology

  • Highly reliable vacuum interrupters - MTTF over 53,000 years

  • Common type 3AH3 operator platform for all ratings

  • Over 60,000 type 3AH3 operators produced since 1998

  • Generator circuit breakers (to IEEE C37.013 optionally available)

  • 10,000 operations to overhaul

  • Three-cycle interrupting time (optional)

  • Meets or exceeds the latest ANSI, IEEE and NEMA standards

  • UL or C-UL Listing available

  • Available as: indoor (type GM-SG), outdoor non-walk-in (type OGM-SG) and outdoor walk-in shelter-clad NEMA 3R (type SGM-SG) (single-aisle and factory insulated and assembled aisle (optional)).

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