Schneider F400 Metal Clad Switchgear

F400 metal clad switchgear is Schneider Electric’s air-insulated, metal-enclosed medium-voltage switchgear range built around withdrawable (floor rolling) circuit breakers, designed to cover electrical power distribution from 1 kV up to 36/40.5 kV. This article explains what F400 is, its breaker/module variants, how to select the right configuration, its rated performance figures, applicable IEC/IEEE standards, and typical applications for utility, industrial, and infrastructure substations. The information here supports procurement and engineering teams sourcing MV switchgear for the Middle East and Gulf region including Egypt and Saudi Arabia, North Africa, CIS countries, and Sub-Saharan Africa, where reliable air-insulated switchgear is a core requirement for grid and industrial substations.

What Is F400 Metal Clad Switchgear

F400 is a metal-enclosed, air-insulated switchgear platform consisting of withdrawable functional units housed in individually earthed metallic compartments, intended for indoor installation in the MV section of HV/MV substations and high-power MV/MV substations. The design integrates a floor rolling trolley for the withdrawable circuit breaker to guarantee reliable connection and alignment to the busbars, eliminating the need for a separate external trolley during racking operations. More than 20,000 F400 cubicles have been installed worldwide, reflecting a long field track record across utility and industrial networks.

Circuit Breaker Technologies and Module Variants

F400 supports two interchangeable circuit breaker technologies — vacuum and SF6 — sharing the same operating mechanism and cubicle footprint, which allows full interchangeability between breaker types without redesigning the cubicle. The range is offered with three breaker variants — commonly identified in the catalog as SF1, SF2 and HVX — covering different rated voltage and breaking-current combinations described below.

Each functional unit includes a rotary-design voltage transformer for easy maintenance and replacement, and cable connection points positioned higher than 1 meter to simplify termination work. Up to four cable runs per phase are possible in the standard cubicle design. The busbar is located at the bottom of the cubicle, avoiding heavy overhead lifting during installation and maintenance.

Rated Performance: Circuit Breaker Specification Table

(Source: Schneider F400 Metal Clad Switchgear.pdf — breaker performance chart)

In addition to breaker breaking capacity, F400 enclosures are classified to withstand internal arcing at up to 31.5 kA for 1 second under the AFLR internal arc classification. An optional arc protection unit can detect an internal arc flash event and trip the feeding breaker automatically to limit fault energy.

Selection Criteria for F400 Cubicles

When specifying F400, buyers should evaluate:

• Rated voltage class — 36 kV or 40.5 kV depending on network requirements.
• Breaker technology — vacuum or SF6, selectable per project preference since both share the same cubicle and control interface.
• Internal arc protection level (LSC2B / AFLR) — F400 cubicles use earthed metallic partitions between MV compartments (LSC2B), isolating each compartment against electrical, mechanical and thermal fault effects.
• Seismic requirement — F400 has certified seismic withstand of 1.25 g, suitable for regions with seismicity up to magnitude 8 on the Richter scale.
• Footprint constraints — cubicle width from 900 mm, height from 2,255 mm (without VT) up to 2,335 mm (with VT), and depth of 2,724 mm (available with forced ventilation at 2500 A).
• Digital integration needs — compatibility with EcoStruxure Grid/Power architecture, PowerMeter, Circuit Monitor, GemControl, and Easergy series protection relays for remote monitoring and control.
• Maintenance interval expectations — F400 requires only routine operating checks, cleaning and greasing every 5 to 10 years, and is designed for a 30-year service life.

Safety and Operational Features

F400 emphasizes operator safety through several embedded design elements. All routine operations — opening, closing of circuit breaker and earthing switch — can be carried out remotely, keeping operators away from the cubicle front during switching. A single “anti-reflex” handle is used for all manual operations to reduce operator error. A Voltage Presence Indicator System (VPIS) on the front panel confirms the absence or presence of energy before the earthing switch is operated. Racking the withdrawable breaker in or out is only possible with the cubicle door closed, and mechanical/electrical interlocks are embedded throughout the range. The earthing switch is rated with making capacity, an important safety attribute for fault-closing scenarios.

Digital and Monitoring Ready Solutions

F400 is positioned as an EcoStruxure-ready switchgear platform, supporting connected sensors such as Easergy TH110 (thermal) and Easergy CL110 (environmental), arc sensors, and remote-controlled circuit breaker and earthing switch actuators, feeding into EcoStruxure Grid or EcoStruxure Power architectures for substation monitoring, asset advisory, and SCADA integration. Direct access to product documentation — catalogs, user guides, relay manuals — is available via QR codes printed on the front door of each cubicle.

Applications

F400 is applied across utility and industrial installations, including:

• Power supply companies: HV/MV substations, MV/MV substations, MV/LV substations, and power generation facilities.
• Industry: oil & gas, chemical, automotive, and mining/mineral/metal industries.
• Infrastructure: airports, ports, and water treatment plants.
• Seismic zones: certified for seismic environments up to magnitude 8 equivalent loading.

Standards and Compliance

F400 internal arc withstand performance is developed for all functional units to achieve the AFLR protection class in accordance with IEC/EN 62271-200. F400 is fully compliant with metal-enclosed switchgear IEC standards, and its seismic certification for 1.25 g references IEEE 693 (2018), IEC 60068-3-3, IEC 62271-210, and IEC 60068-2-6. Design, manufacturing and testing follow ISO 9001:2008 quality standard, with type testing performed for each performance level in the range.