Silicone - Tube Design

Our arresters with silicone housing in tube design of the SBKT series are available for applications up to 800 kV.

Similar to porcelain housed arresters they use a hollow insulator as housing. This so called composite insulator is made of a fibreglass reinforced plastic tube (FRP), with silicone rubber sheds directly moulded onto it. Composite insulators do have a very high mechanical stability.

As for all our arresters with silicone housing 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. An outdstanding sealing system prevents from any moisture ingress and assures a long service life time.

Due to their very high mechanical stability, SBKT arresters from Tridelta are best suitable for applications up to 800 kV networks as well as for areas with high seismic activity. Even after an arrester failure our SBKT arresters will maintain more than 75% of their mechanical stability. Because of this SBKT arresters can also be used as supporters where the arrester besides its electrical function serves as a post insulator e.g. to support a busbar.

Our Products

Technical Data

Product   SBKT size I SBKT size II
Highest System Voltage Us kV 550 800
max. Rated Voltage Ur kV 444 624
max. Nominal Discharge Current In (at 8/20 µs waveshape) kA 20 20
max. Thermal Energy Absorption Capability kJ per kV of Ur 10 18
max. Line Discharge Class   4 5
Arrester classification   SM, SH SM,SH
Qrs (accord. IEC 60099-4 Edt. 3.0)   3,6 4,4
High Current Withstand Strength 4/10 µs kA 100 100
max. Low Current Withstand Strength 2 ms A 1.700 2.600
max. Short Circuit / Pressure Relief Capability kA - 0,2s 65 80
Mechanical Strength: Specific short-term load SSL Nm 12.000 23.000


  • 550 kV, Interconnexion Electrica S.A.
  • 550 kV, Alstom / KEGOC Kazakhstan
  • 420 kV, Iskerenderun Enerji Üretim, Turkey
  • 420 kV, Golgohar S/S, Sirjan Iran, desert climate