Siemens Power Transmission & Distribution, Inc. has introduced its next-generation medium-voltage air insulated switchgear product, the GM-SG. Based on the Siemens GM switchgear design, the GM-SG now uses the globally proven Siemens 3AH3 operator. The German-designed 3AH3 operator is used in eight circuit breaker and switchgear products around the world. The 3AH3 operator enables the GM-SG to provide higher performance including faster interrupting times and higher interrupting currents. More than 160,000 3AH breaker operators have been delivered to customers worldwide since its launch in 1998.

The GM-SG will initially be offered at 5 kV and 15 kV, with rated currents up to 3000 A, self-cooled and interrupting currents up to 50 kA with 3-cycle interruption. Deliveries start in early 2007. This will be followed by a two-high arc-resistant version as well as a 63 kA interrupting rating later in 2007.

”The 3AH3 will be the common circuit breaker for all Siemens ANSI medium voltage switchgear/circuit breaker products. This includes the GM-38kV, the SDV6 distribution circuit breaker and the Siemens retrofit breaker. By standardizing on the 3AH3, we are able to offer a range of superior switchgear products while being able to meet customers’ demands for quality and life cycle costs,” advises Doug Keith, vice president of the Distribution Products Division. The 3AH3 doubles the life and number of available operations when compared with the current GMI breaker.

The GM-SG is to be manufactured at the Siemens switchgear factory in Queretaro, Mexico. Siemens has made a considerable investment in the existing Queretaro operation to manufacture the GM-SG including new plant equipment, manufacturing/quality processes and a building extension that doubled the factory floor area. Customer interfaces such as marketing, customer service, project management, design engineering and order engineering will continue to be performed out of the Wendell, North Carolina, facility.