Silicone - Cage Design

Tridelta offers arresters with silicone housing in Cage Design of the SBKC series for applications up to 420 kV.

Fibreglas reinforced plastic rods (FRP) are fixed in the arrester terminals by means of a TRIDELTA patented technique and form a kind of cage around the metaloxide varistor blocks which provides a high mechanical stability to the arrester. The direct moulding of the active part with LSR silicone prevents from any moisture ingress and ensures a high reliability. We use high quality LSR silicone which keeps its hydrophobic and UV-resistant/non ageing properties over the complete service life and ensures excellent artificial pollution performance.  

Our SBKC arresters in Cage Design are suitable for applications with advanced mechanical requirements and offer an outstanding price-performance ratio.  They can be installed in substations in stationary or suspended installation and are best adapted for use as line arresters for protection of transmission lines. High level and stable manufacturing quality on newest machinery as well as testing with state-of-the-art test equipment assure a long service life.

Our Products

Technical Data

Product   SBKC size 0 SBKC size II
*higher ratings for line
arrester applications (TLA) available on request
Highest System Voltage Us kV 170 420*
max. Rated Voltage Ur kV 144 360*
max. Nominal Discharge Current In (at 8/20 µs waveshape) kA 10 10
max. Thermal Energy Absorption Capability kJ per kV of Ur 4,5 9,2
max. Line Discharge Class   2 4
Qrs (accord. IEC 60099-4 Edt. 3.0)   1,2 2,8
High Current Withstand Strength 4/10 µs kA 100 100
max. Low Current Withstand Strength 2 ms A 500 1.500
max. Short Circuit / Pressure Relief Capability kA - 0,2s 40 63
Mechanical Strength: Specific short-term load SSL Nm 1.200 4.000


  • 138 kV ENEL, Italy
  • 400 kV Fingrid Petäjäskoski, Finland
  • 220 kV OETC Oman, S/S SFZ, extra long creepage >45 mm/kV
  • 356 kV, KEPCO South Korea
  • 245 kV, HMV Ingenieros Ltda., Colombia