3EL – Surge arresters with directly molded silicone rubber housing, Cage Design®
Siemens 3EL silicone rubber surge arresters with Cage Design® provide outstanding protection against overvoltages in networks up to 800 kV.
|Siemens 3 EL Cage Design® surge arresters are ideally suited for the reliable protection of:
– Circuit breakers
– Traction vehicles
– Transmission lines
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.