Schneider Electric SM AirSeT SF6-free modular switchboard

Manufacturer: Schneider Electric

Schneider SM AirSeT, the SF6-free modular MV switchboard to 24 kV on pure air and shunt vacuum interruption

This model is part of SecondWatt’s switchgear research catalogue. Specifications and price observations are included where supported by sources. Equipment availability and commercial terms require confirmation.

Schneider Electric SM AirSeT dossier: pure-air modular MV switchboard to 24 kV with SVI vacuum switching, SM6 compatibility, F-gas context, inspection.

Why it matters

SM6 is one of the most installed MV switchboard platforms in the world, and SM AirSeT is its drop-in decarbonization path, which makes it the volume vehicle of the SF6-free transition in secondary distribution. The switchboard-versus-RMU distinction is the practical buyer point: SM AirSeT and RM AirSeT are different products on one platform, and a quote written against the wrong one buys the wrong footprint.

Who buys it

Utilities and campus networks replacing SM6-era SF6 switchboards ahead of the EU 2026 cutoff are the core buyers, with the SM6 footprint compatibility the deciding feature. Data center MV rooms in IEC markets take it for ring and feeder duty; no used channel exists to buy from.

Role in the data center

SF6-free medium-voltage ring and feeder switchboards in IEC-market campus networks, particularly as SM6 replacements dropped into existing electrical rooms where the footprint compatibility avoids civil work. It sits between the campus loop and the unit substations serving individual halls.

Key specifications

Technical summary

Voltage: up to 24 kV. Technology: pure air + Shunt Vacuum Interruption (SVI); CompoDrive mechanism. Functional units: switch, switch-fuse, circuit breaker. Switching: 3-position (closed / open / earthed). Digital: wireless condition sensors, arc detection relay, optional T300 RTU. Compatibility: SM6 footprint and interface. Design life: 40 years. Debut: 2021-04-13; pilots with GreenAlp, EEC Engie, E.ON, Renault.

Major variations

Modular switchboard configurations are assembled from switch, switch-fuse and circuit-breaker functional units, all using three-position switching and the CompoDrive mechanism, with wireless condition sensors and the T300 RTU as options. The same pure-air platform carries RM AirSeT, the sealed 12/24 kV ring main unit with integrated T300, and GM AirSeT, the primary gas-insulated switchgear. SM AirSeT is the switchboard and RM AirSeT is the ring main unit, a distinction that decides whether a quote is even for the right product.

Configurations and options

Switchboards are assembled from switch, switch-fuse and circuit-breaker functional units, all using three-position switching, closed, open and earthed, and the CompoDrive mechanism, so unit count and duty mix set the price. The digital options are the separable content: wireless condition-monitoring sensors, an internal arc detection relay, and a T300 remote terminal unit. Footprint compatibility with the SM6 installed base is a designed-in property rather than an option, and it decides whether a replacement needs civil work. Rated current, short-circuit, BIL and internal arc values are published in the SM AirSeT catalogues rather than on the public range pages, so acceptance documents should cite the catalogue.

Compatibility and dependencies

Insulation is pure air with Shunt Vacuum Interruption, so there is no F-gas inventory and no gas handling at any point in the asset's life. The interoperation that sells this product is with the existing SM6 fleet: it is footprint- and interface-compatible with SM6, which is what lets a replacement drop into an existing electrical room. Downstream, the three-position switch provides the earthing function the maintenance procedure depends on, and the optional T300 RTU is the interface to a distribution automation or SCADA system. One naming distinction decides whether a quote is even for the right product: SM AirSeT is the modular switchboard, while RM AirSeT is the compact sealed ring main unit on the same platform.

Pricing and availability

Trend: rising Lead time, new: 32-50 weeks (secondary/pad-mount class proxy). Lead time, used or refurbished: No used supply exists. Warranty, used: 1-year typical from reconditioning dealers.

Lifecycle and maintenance

Gas-insulated switchgear targets 35-40 year service from sealed-for-life compartments with minimal maintenance: density monitoring, PD surveys, and mechanism service. Sealed tanks cannot be repaired in the field, so gas loss or internal fault usually ends the asset. EU F-gas and CARB rules add end-of-life SF6 recovery and reporting obligations that must be priced into any SF6 unit, while SF6-free designs (clean air, dry air, C4-FN mixtures) remove that liability entirely.

Thermal and emissions profile

Switchgear produces no combustion emissions, and SF6-free designs remove the category's one regulatory exposure: instead of SF6 (GWP 24,300), these units insulate with clean air, dry air, or pure air at GWP below 1 and interrupt in vacuum. That satisfies EU F-gas Regulation 2024/573, which bars new SF6 MV switchgear from the EU market from 2026, and California's CARB phase-out of new SF6 equipment acquisitions from 2025. Buyers avoid gas handling, leak reporting, and end-of-life recovery costs entirely.

Common failure points

• Gas leakage — Density alarms and lockout; insulation margin lost as pressure falls
• Partial discharge in compartments — PD at spacers, particles, or terminations progressing to internal fault
• Operating mechanism — Spring and motor failures on switch and breaker drives
• Cable terminations — Tracking in cable boxes and poorly seated plug-in connectors
• Density monitor drift — False alarms or missed low-gas conditions from drifted gauges
• End-of-life gas liability — SF6 recovery and reporting costs land on the owner at decommissioning

Inspection checklist

Gas density: verify density monitors against nameplate fill (150 kPa class systems); alarm thresholds intact. Leak rate: review gas top-up logs; leakage above 0.5% per year fails modern acceptance. Gas quality: test SF6 moisture and decomposition before transfer; SO2 presence flags internal arcing. F-gas compliance: verify EU 2024/573 and CARB status; new SF6 MV gear is barred from the EU market from 2026. Partial discharge: UHF or acoustic survey per IEC 60270 practice; PD is the dominant latent defect. Vacuum interrupters: hipot test breaking units; interruption is vacuum even in gas-insulated designs. Mechanism: exercise and verify spring charge; check counters against 10,000-operation class ratings. Terminations: inspect cable boxes for tracking; verify stress cones and plug-in connectors seated.

Procurement channels

The SM6 predecessor fleet is the decommission pipeline worth watching, since SM6 removals ahead of the EU 2026 F-gas cutoff are what will put the first sealed secondary-distribution units into the surplus market.

Regional notes

An IEC-market secondary-distribution product that made its commercial debut 2021-04-13 after pilots with GreenAlp, EEC Engie, E.ON Sweden and Renault, with no ANSI listing. Its commercial driver is EU Regulation 2024/573, which bars new SF6 switchgear at and below 24 kV from 2026, and the SM6 fleet being replaced ahead of that date is where the volume sits. A 50 Hz switchboard is not usable on a North American 60 Hz project without significant engineering, and the SM6 footprint compatibility that is the product's main advantage has no equivalent value outside markets where SM6 was installed.