Siemens 8DA10 gas-insulated switchgear (to 40.5 kV)
Siemens 8DA10 single-busbar gas-insulated switchgear to 40.5 kV, 5,000 A and 40 kA.
Siemens 8DA10 gas-insulated switchgear (to 40.5 kV) is one of 41 data center switchgear tracked in the SecondWatt catalogue, each with specifications, lead times and indicative secondary-market pricing.
Siemens 8DA10 dossier: single-busbar GIS to 40.5 kV, 5,000 A, and 40 kA with vacuum interruption, attribution correction, F-gas math, inspection.
Why it matters
8DA10 is the compact-GIS benchmark at 40.5 kV, the exact class where new-build leads run 78-104 weeks, and its 75%-smaller footprint is why GIS keeps winning urban and campus sites despite SF6 rules. Getting the Siemens-versus-Siemens-Energy attribution right also decides where RFQs and service claims actually land.
Who buys it
Utilities and dense urban or industrial substations specify 8DA10 where footprint rules; US data center campuses take the arc-resistant ANSI variant for compact 38 kV-class intake. There is no used channel; buyers needing speed turn to air-insulated stock or cancelled-project GIS lots when they surface.
Role in the data center
Compact 24-38 kV class campus intake and primary distribution where electrical-room footprint is the binding constraint.
Key specifications
| Voltage classes | 12 / 24 / 40.5 kV |
|---|---|
| BIL | 75 / 125 / 185 kV |
| Busbar ceiling | 5,000 A |
| Short-time withstand | 40 kA / 3 s |
| Internal arc | IAC A FL / FLR 40 kA 1 s |
| Mechanical endurance | 30,000 operations (vacuum) |
| US arc-resistant class | IEEE C37.20.7 Type 2B, 40 kA 0.5 s |
| Footprint claim | ~75% smaller than AIS |
| Owner correction | Siemens AG Smart Infrastructure |
Technical summary
Voltage classes: 12 / 24 / 40.5 kV BIL: 75 / 125 / 185 kV (phase-earth) Busbar: up to 5,000 A; feeders 2,750-3,150 A Short-time withstand: 40 kA / 3 s (all classes) Internal arc: IAC A FL / A FLR 40 kA 1 s Interruption: vacuum (30,000 mechanical operations); SF6 insulation only US variant: arc-resistant IEEE C37.20.7 Type 2B; ~75% smaller than AIS SF6-free path: 8DAB 24 / 8DAB 40 Clean Air siblings Standards: IEC 62271-1/-100/-200
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.
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 for new; no open used market for sealed GIS. Decommissioned units route through gas-recovery services; Surplus Record's Siemens category is the long-shot monitor.