Siemens NXPLUS C compact gas-insulated switchgear (to 24 kV)
Manufacturer: Siemens
Siemens NXPLUS C compact GIS to 24 kV, 2,500 A, and 31.5 kA, with a clean-air 24 blue variant shipping
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.
Siemens NXPLUS C dossier: compact GIS to 24 kV, 2,500 A, and 31.5 kA with a clean-air 24 blue variant, Siemens AG ownership, inspection checklist.
NXPLUS C is Siemens AG Smart Infrastructure's compact gas-insulated MV switchgear for primary distribution: sealed, climate-independent and maintenance-light, with vacuum interruption inside gas-insulated compartments in single and double-busbar builds. The catalogue rating table is banded, and the bands matter: 7.2, 12 and 15 kV panels carry 31.5 kA rated short-circuit breaking current and 2,500 A feeders, while 17.5 and 24 kV panels carry 25 kA and 2,000 A feeders. Busbars reach 2,500 A across the range. Siemens AG has been separate from Siemens Energy AG since the September 2020 spin-off, and this is a Siemens AG product.
The transition variant matters: NXPLUS C 24 blue replaces SF6 insulation with clean air while keeping the compact footprint, extending Siemens' blue GIS portfolio into the primary-distribution class ahead of the EU F-gas cutoffs. A wind-duty variant (NXPLUS C Wind) serves turbine towers.
Like all sealed MV GIS, value tracking belongs at the spares and service level, and the SF6-versus-clean-air split will govern residual values as the F-gas deadlines land.
Why it matters
NXPLUS C is the volume compact-GIS platform below the 8DA/8DB flagship, exactly the class data center MV rooms specify when floor space is tight. Its blue variant is one of the few shipping SF6-free primary GIS options, making the SF6-versus-clean-air choice on this platform a template for the category's stranded-asset math.
Who buys it
Utilities, industrials, and space-constrained campus substations specify NXPLUS C new; wind operators take the tower variant. There is no used channel; owners buy service, gas work, and eventual blue replacements through Siemens and its service partners.
Role in the data center
Compact primary MV switching in space-constrained campus electrical rooms; the blue variant future-proofs against F-gas exposure.
Key specifications
| Voltage ceiling | 24 kV |
|---|---|
| Busbar ceiling | 2,500 A |
| Short-time withstand | 31.5 kA |
| Architecture | sealed compact GIS, single/double bus |
| SF6-free variant | NXPLUS C 24 blue (clean air) |
| Wind variant | NXPLUS C Wind (tower duty) |
| Brochure | NXPLUS C 24 blue GIS brochure |
| Manufacturer | Siemens AG Smart Infrastructure |
Technical summary
Voltage classes: 7.2 / 12 / 15 / 17.5 / 24 kV. Busbar: up to 2,500 A across the range. Feeders: 2,500 A at 7.2-15 kV; 2,000 A at 17.5-24 kV. Rated short-circuit breaking current: 31.5 kA at 7.2-15 kV; 25 kA at 17.5-24 kV. Rated short-time withstand: the same values for 3 s. Internal arc: IAC A FL wall-standing and IAC A FLR free-standing, at 31.5 kA 1 s (7.2-15 kV) and 25 kA 1 s (17.5-24 kV). Builds: single and double busbar in sealed gas compartments. Interruption: vacuum; insulation SF6 (standard) or clean air (NXPLUS C 24 blue). Variants: NXPLUS C, NXPLUS C 24 blue, NXPLUS C Wind. Standards: IEC 62271 series.
Major variations
Standard SF6-insulated builds, the clean-air 24 blue variant, and the Wind tower build; single versus double busbar. The 8DA10/8DB10 platform sits above it for 40.5 kV and 5,000 A duties.
Configurations and options
The voltage class changes the electrical envelope rather than just the insulation level, and that is the first order decision: panels at 7.2, 12 and 15 kV carry 31.5 kA rated short-circuit breaking current with 2,500 A feeders, while 17.5 and 24 kV panels carry 25 kA with 2,000 A feeders. Busbars reach 2,500 A across the range. Beyond that, the choices are single or double busbar, the panel duty, and the variant: standard SF6 build, the clean-air NXPLUS C 24 blue, or NXPLUS C Wind for turbine towers. Internal arc classification is IAC A FL wall-standing or A FLR free-standing at the band's rating for 1 second.
Compatibility and dependencies
Vacuum interruption inside sealed gas compartments, so the compartments are not field-repairable and the interfaces are cable terminations, busbar couplings, density monitoring and relay wiring. The compact footprint is the reason to choose it and it constrains cable entry, termination space and the arc exhaust path, all of which have to match the arrangement the IAC A FL or A FLR classification was tested in. Ratings must be read against the voltage band rather than the family: a panel specified at 24 kV withstands 25 kA and carries 2,000 A feeders, not the 31.5 kA figure that applies at 15 kV and below. The 8DA10 and 8DB10 platform sits above the family for 40.5 kV and 5,000 A duties.
Pricing and availability
Trend: up Lead time, new: 60-104 weeks (MV GIS class). Lead time, used or refurbished: No used channel (sealed-for-life). 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
The regulatory story is the insulation gas: SF6 carries a global warming potential of 24,300 and an atmospheric lifetime near 3,200 years. EU Regulation 2024/573 bars placing new SF6 switchgear at or below 24 kV on the EU market from 2026-01-01, extends to 52-145 kV classes from 2028, above 24 to 52 kV from 2030, and above 145 kV from 2032. California's CARB rule phases out acquisition of new SF6 gas-insulated equipment from 2025 on a staged schedule. Legacy SF6 gear remains legal to operate but faces stranded-asset discounts and end-of-life gas recovery obligations.
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 Enclosure — verify sealed-compartment integrity (IP65 class HV parts), pressure relief, and corrosion Interlocks — verify 3-position switch logic (closed/open/earthed) and padlock provisions Gas handling — confirm certified handling equipment and trained personnel for any gas transfer Monitoring — verify density and PD telemetry channels report correctly to the control system Nameplate — confirm kV class, BIL (75-185 kV in MV GIS), kA rating, and busbar current Standards — IEC 62271-200 (or -203 HV) type-test documentation present and matching configuration Records — gas logs, factory routine tests, and service history; sealed units without logs reprice sharply
Procurement channels
Siemens channels only; no used NXPLUS C unit was listed as of August 2026. Spares-and-service planning at purchase is the availability strategy for this class.
Regional notes
An IEC 62271-series product for European-style primary distribution with no ANSI listing, so a 50 Hz panel is not usable on a North American 60 Hz project without significant engineering. The owner is Siemens AG, Smart Infrastructure; Siemens Energy AG has been a separate listed company since the September 2020 spin-off and has never sold this line. EU Regulation 2024/573 bars new SF6 switchgear at and below 24 kV from 2026, which is the deadline the clean-air NXPLUS C 24 blue variant answers and the reason SF6 and clean-air panels will diverge in residual value.