SIEMENS 3EK4 AND 3EK7 MEDIUM VOLTAGE SURGE ARRESTERS FOR DISTRIBUTION NETWORKS

Siemens 3EK4 and 3EK7 silicone rubber surge arresters with cage design effectively protect medium-voltage distribution networks from overvoltage.

Siemens 3EK4 and 3EK7 cage design surge arresters are ideally suited to provide reliable protection for:

• Transformers
• Circuit breakers
• Medium-voltage switchgear
• Medium-voltage distribution networks

The cage, made of fiberglass-reinforced plastic (FRP) rods, provides a rigid, reinforced structure ensuring high mechanical strength.

The silicone rubber housing is directly molded onto the metal oxide (MO) blocks and the surrounding cage made of FRP rods. This creates a reliable seal that prevents moisture ingress and partial discharges.

The MO resistors are not surrounded by a rigid mechanical coating, which is why no critical increases in pressure can occur in the surge arrester in the extremely rare event of an overload. The arc can escape directly through the soft silicone housing without damaging the mechanical structure. No internal parts are ejected in the process. The innovative Siemens cage design is very secure.

The silicone rubber is highly hydrophobic. This keeps any conductive moisture from forming on the surface, and dirt deposits are rendered harmless as a result of the hydrophobic transfer. Silicone is highly fire-retardant and self-extinguishing in the event of fire. These properties ensure the reliable, maintenance-free operation of 3EK surge arresters.

Siemens offers two types of products for use in distribution networks that differ in terms of mechanical strength:

• 3EK4 – for rated voltages up to 36 kV, high mechanical strength
• 3EK7 – for rated voltages up to 60 kV, very high mechanical strength

The proven type 3EK7 surge arrester is also available for indoor use. The 3EK7 surge arrester for indoor use is a cage design surge arrester that offers the same features as the version for outdoor use.

Siemens 3EK4 and 3EK7 : Siemens Transmission Products – Leader in innovations with comprehensive, connective and sustainable portfolio

Transmission products play a vital role in the energy value chain. Siemens Transmission Products provides all key elements including power transformers and distribution transformers as well as gas-insulated and air-insulated switchgear and components. Products are offered individually, bundled or with related engineering upgrade to systems. Our products offer low life cycle costs with maximum availability, highest efficiency and short commissioning times.

We are driving technology innovations not only regarding the performance of transmission products but also in the area of sustainability and eco efficiency. By merging physics and data we enable new products and applications: Sensformer® and Sensgear®. With our global factory network and leading innovations we provide the highest level of quality and reliability to our customers: TSOs, DSOs, power producers, EPCs and industrial companies.