Mitsubishi Electric C-GIS cubicle-type gas-insulated switchgear (12-72.5 kV)
Mitsubishi Electric C-GIS cubicle switchgear from 12 to 72.5 kV, the Japanese-market compact GIS platform
Mitsubishi Electric C-GIS cubicle-type gas-insulated switchgear (12-72.5 kV) is one of 41 data center switchgear tracked in the SecondWatt catalogue, each with specifications, lead times and indicative secondary-market pricing.
Mitsubishi Electric C-GIS dossier: cubicle-type gas-insulated switchgear 12-72.5 kV, service-network risk on imported units, F-gas context, inspection.
Why it matters
C-GIS is the Japanese entrant in a compact-GIS market otherwise dominated by European OEMs, and its 72.5 kV ceiling reaches duties where alternatives narrow. For SecondWatt, the practical value is warning US buyers about service-network risk on imported sealed gear, a real exposure no marketplace currently flags.
Who buys it
Asian utilities and industrials specify C-GIS directly; US and EU exposure arrives through imported package substations and Japanese corporate facilities. Owners of US-landed C-GIS need Mitsubishi service relationships confirmed, because third-party support for sealed Japanese GIS is thin.
Role in the data center
Compact MV switching in imported package substations and Japanese-affiliated facilities; rarely specified directly by US campus developers.
Key specifications
| Product type | cubicle-type GIS (C-GIS) |
|---|---|
| Voltage scope | ~12-72.5 kV |
| Interruption | vacuum inside gas-insulated enclosure |
| Portfolio | Mitsubishi Electric Energy Systems |
| Competitive set | Siemens 8DA/NXPLUS C, ABB ZX, Eaton XGIS |
| Secondary market | no listings observed |
| US exposure route | imported package substations |
| Class lead time | 60-104 weeks (MV GIS class) |
Technical summary
Type: cubicle-type gas-insulated switchgear (C-GIS) Voltage classes: approximately 12-72.5 kV Construction: sealed gas-insulated cubicles with vacuum interruption Portfolio: Mitsubishi Electric Energy Systems switchgear Position: compact GIS competing with Siemens, ABB, Eaton platforms Top-end reach: 72.5 kV subtransmission band Market: Japan and Asia primary; global selective Secondary market: none observed
Pricing and availability
Trend: up Lead time, new: 60-104 weeks (MV GIS class). Lead time, used or refurbished: No used channel observed. 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