High-voltage switchgear and breakers

Types of switchgear we source

• Air-insulated switchgear (AIS). Equipment that uses open air as the insulating medium. It needs more space but is often simpler to inspect and maintain. Common at outdoor transmission and distribution substations.
• Gas-insulated switchgear (GIS). Equipment enclosed in sealed compartments filled with an insulating gas. It takes far less space, which makes it common in urban substations, data center campuses and sites with limited land.
• High-voltage circuit breakers. Live-tank and dead-tank breakers for transmission and generation interconnections.
• Medium-voltage switchgear. Metal-clad and metal-enclosed lineups for collector systems, plant auxiliaries and distribution.

Sourcing switchgear alongside transformers

Most of our searches start with a transformer, but the switchgear question usually follows. If the transformer arrives on time and the breakers do not, the project still waits. We look at both together so the delivery dates line up.

The approach is the same as for transformers. We contact manufacturers about open production slots, look for surplus and never-energized equipment from cancelled projects, and check documentation on anything that is not new. For a used breaker or GIS bay, that includes maintenance and operation records as well as test reports.

What we check

• Rated voltage, continuous current and short-circuit interrupting rating.
• Basic insulation level and the applicable standards, IEEE/ANSI or IEC.
• Configuration, such as breaker-and-a-half, ring bus or main-and-transfer, and the number of bays.
• Control and protection interfaces, and whether they match your utility's standards.
• For GIS, the insulating gas used, and any rules that apply to it at your site.
• Space, foundation and access requirements.

Manufacturers

Switchgear comes from a different mix of manufacturers than transformers, though some companies make both. We follow capacity and lead times at domestic and international suppliers and compare options on spec, delivery date, tariffs and compliance. Our current list is on the equipment page.

Starting a search

A single-line diagram and the required energization date are the most useful starting points. If you are also looking for a power transformer or GSU, tell us both at once. You can start a search or read how we work.