Industry’s first medium voltage metal-clad switchgear

Siemens Power Transmission and Distribution has unveiled what it claims is the industry’s first globally compliant medium voltage metal-clad switchgear.

Siemens Power Transmission and Distribution, an affiliate of Siemens Corporation and Siemens AG, has unveiled what it claims is the industry’s first globally compliant medium voltage metal-clad switchgear – the NXAIR P.

‘NXAIR P is the culmination of a seven-year research and development project undertaken by Siemens to revamp our entire line of air insulated switchgear,’ said Jan van Dokkum, president and CEO of Siemens Power Transmission and Distribution.’

To fully meet ANSI and IEC global standards, the new Siemens switchgear incorporates arc-venting flaps designed to increase operator safety. ‘Safety is a growing concern for our customers, making arc vented technology more important than ever,’ said David Lin, Siemens product manager for the NXAIR P. ‘Siemens has been doing arc fault tests for more than 25 years, and we drew on this experience to incorporate the arc venting feature into the new design.’

Unlike a three-phase bolted fault, an arcing fault creates an enormous amount of heat, which results in an extreme pressure buildup within a switchgear section. Arc vented switchgear channels and directs the expanding gases up and away from the operator to relieve this pressure buildup.

The NXAIR P is fully compliant with the new IEEE C37.20.7 arc- venting standard for the ANSI market and the IEC 60298 arc-venting standard that has been in force since 1981.

The NXAIR P has a one-high breaker design. It also features optional front primary cable access to allow flush mounting with the back wall.

A back-to-back lineup with front primary cable access requires 59% less space than existing ANSI equipment. If a project requires top cable entry, which would require an 18-inch rear extension, the NXAIR P still uses 25% less space than existing ANSI switchgear. The NXAIR P is 63 inches deep by 31.5 inches wide compared to traditional switchgear that measures approximately 94 inches deep by 36 inches wide.

The NXAIR P has four modular compartments: circuit breaker compartment, low voltage compartment, main bus compartment and cable connection compartment.

‘The NXAIR P’s modular design simplifies configuring, manufacturing and delivery,’ said Lin. ‘And the low voltage panel is designed to be easily installed or removed in the field, which is especially beneficial on fast track projects when the primary portion of the equipment needs to be installed in advance of the relaying, metering and control components.’

Designed with the ANSI customer in mind, the NXAIR P has interrupting ratings of 250MVA – 1000MVA and 25kA – 50kA, voltage classes of 5kV and 15kV, and a continuous current of 1200A – 4000A. The switchgear features vacuum interrupter circuit breaker technology.

NXAIR P meets all requirements for the American National Standards Institute (ANSI) and the International Electrotechnical Commission (IEC). It will also carry third-party listings from the Canadian Standards Association (CSA) and Underwriters Laboratories (UL). This enables users to source and maintain identical equipment for all their facilities worldwide.

The NXAIR P will be manufactured in the US and Europe.