Primary switchgear 8DN8

AChigh-voltagedry air-insulated

Overview
The Blue portfolio from Siemens Energy delivers SF6-free gas-insulated switchgear (GIS) and gas-insulated busduct using clean air insulation combined with vacuum switching technology. Blue solutions are engineered to achieve Zero GWP, zero toxic decomposition products, and to remove handling safety requirements related to F‑gases. They are designed for efficient, environmentally friendly, and reliable power transmission across onshore substations, offshore wind applications, industrial installations and busduct applications.

Key benefits

• Zero harmful greenhouse gases in operation (clean air insulation).
• Vacuum switching technology enabling SF6-free interruption.
• Modular, compact designs for space- and weight-constrained sites.
• Optimized footprint and lighter installations via Low Power Instrument Transformers (LPIT).
• Integrated digital options for enhanced productivity and condition monitoring.

Featured products / variants in the Blue portfolio

• 8VM3 / 8VM3-1 Blue GIS: customizable switchgear operating at 72.5 kV with compact modular design; variants optimized for onshore and offshore use; options with built-in Sensgear™ digital technology.
• 8VM1 Blue GIS: 72.5 kV GIS tailored for installation in wind turbines; vacuum circuit breaker with clean air insulation; optimized for turbine applications.
• 8VN1 Blue GIS: first 145 kV GIS with vacuum circuit breaker and clean air insulation; designed for an optimized footprint using LPIT technology.
• 8VN1 (installations): example of large-scale deployment in substations (illustrative of 145 kV variant).
• Blue Gas-Insulated Busduct (Blue GIB): world's first busduct using clean air insulation for voltages up to 420 kV; reduces F‑gas usage versus conventional solutions.
• Other established GIS technologies referenced: 8DN9 (system voltages up to 245 kV onshore / 300 kV offshore), 8DQ1 (rated voltages up to 550 kV), 8DN8 (rated up to 170 kV, compact and flexible).

LPIT (Low Power Instrument Transformer)

• Combined electronic voltage and current transformer replacing conventional instrument transformers.
• Redundant sensors: typically two current sensors and one voltage sensor per bay.
• Multi-purpose device used for protection and measurement; standardized across rated currents.
• Flexible installation within GIS enabling approximately 30% bay length reduction and up to ~1,500 kg weight reduction per bay.

Digital integration
Noedra Node and related digital substation solutions provide real-time data acquisition, advanced analytics and secure automation for holistic substation health and performance monitoring. Digital integration supports early anomaly detection, reduced forced outages and optimized maintenance planning.

Success stories and deployments

• Hornsea 3: large offshore wind farm deployment using Blue 8VM1 GIS (industrial-scale SF6-free installation).
• Netze BW Burladingen substation: deployment of clean-air Blue switchgear at 145 kV combined with digitalization technologies.
• Feralpi Stahlwerke green steel project: installation of F‑gas-free 110 kV Blue switchgear to support decarbonization efforts.
• Fingrid (Finland) order: multiple bays of Blue GIS replacing F‑gases with clean air for a significant national installation.

Technical specifications

• Insulation medium: clean air (mixture of nitrogen and oxygen) — SF6-free, Zero GWP.
• Switching technology: vacuum circuit breakers.
• Typical rated operating voltages by variant: 72.5 kV (8VM3 / 8VM1 / 8VM3-1), 145 kV (8VN1), 170 kV (8DN8), 245–300 kV (8DN9 ranges), up to 420 kV (Blue Gas-Insulated Busduct), up to 550 kV (8DQ1).
• LPIT benefits: combined V & I measurement, redundancy, ~30% bay length reduction, ~1,500 kg weight reduction per bay.
• Design: modular, compact, suitable for indoor/outdoor and offshore installations (variants optimized for wind turbines).
• Digital options: built-in Sensgear™ features (where specified) and Noedra Node compatibility for remote monitoring, analytics and condition-based maintenance.
• Environmental/standards focus: engineered to meet evolving F‑gas regulatory requirements and to enable net‑zero switching technology deployments.