Bushing Boots 11kV Switchgear & Transformer Cable Boxes | Nexans FB1 & FB2

Bushing Boots 11kV Switchgear & Transformer Cable Boxes FB1

Bushing Boots | Large UK Stocks & Competitive Prices

Bushing Boots

Insulating Boots For Switchgear & Transformer Bushing & Termination Connections

Nexans FB1 and FB2 are bushing boots suitable for insulating MV HV bushings in switchgear and transformer cable termination boxes up to 17.5kV – flexible cold-applied bushing boots are typically used as 11kV bushing boots where the clearances between phase and phase to earth is less than the normal air clearance.

Nexans FB1 bushing boots, used in conjunction with Cold Shrink or heat shrink terminations, protect against flashover in the event of high humidity and surge impulses (basic impulse level BIL 95kV).

The FB1 boots are quick and easy to install and are manufactured from highly insulating flexible and weather resistant material with excellent tracking and erosion resistance for high voltage electrical insulation and flash over prevention.

The bushing boots are cold-applied without requirement to heat shrink onto the equipment bushing of the electrical equipment – this allows the FB1 kit to achieve an universal connection including straight or right-angled to the switchgear or transformer bushings up to 400sqmm cross section area conductor or 46-70mm bushing diameters.

Compatible with both cold shrink, cold applied, push-on and heat shrink terminations.

The bushing connection can be easily accessed for testing using 11kV detectors and the boot is simply to reinstall after testing without the need for additional material or tooling. The cable termination can be energised immediately after installation and the bushing boots have an unlimited shelf life:

  • 6/10 (12) kV
  • 6.35/11 (12) kV
  • 8.7/15 (17.5) kV

The Nexans FB1 kit comprises of 3 flexible bushing boots and 3 tubes of grease.

Although these bushing boots are compatible with both Cold Shrink and heat shrink terminations a range of both straight and right-angled heat shrink boots and Cold Shrink boots are available to insulate switchgear and transformer cable connections, typically at 6.6kV/11kV/33kV. The bushing boots are installed onto switchgear and transformers by the Jointer where the clearances are insufficient for operation in air or to protect against flash-over due to extreme humidity.

The flexible bushing boot kits are an unscreened boot and therefore not safe to touch when energised. Cable terminations can be energised after installation. 


Bushing Boots

Nexans FB1

Bushing Boots

Technical Specification

The bushing boots are manufactured from a highly insulating and anti-tracking silicone rubber based material with excellent weathering properties for long service life on medium voltage electrical systems.

  • Basic Impulse Level – 95kV
  • Bushing Diameter – 30 – 45mm
  • Cable Sizes – 35 – 400sqmm
  • Voltage Um – 17.5kV max
  • Description – Flexible Bushing Boots
  • Diameter D Over Termination – 35mm-400mm
  • 11kV Switchgear & Transformer Bushing Boots

Bushing Boots

Cable Terminations

Minimum Clearances For Indoor Cable Termination Kits

➡ Check the cable box for minimum clearances and refer to the table immediately below – if the actual dimension “A” and “B” is less than the value give, a bushing boot must be fitted.

Nexans Kit Number Nexans Product  Maximum Voltage  Cable Range  Bushing Diameter Range 
FB-2 Set of 3 Boots 24kV 185-630sqmm 46-70mm
FB-1 Set of 3 Boots 24kV 35-300sqmm 46-70mm
FB-1 Set of 3 Boots 17.5kV 35-400sqmm 46-70mm
FB-0 Set of 3 Reducing Adaptors 17.5kV 35-400sqmm 30-45mm


Voltage Level Uo/U (Umax) kV 3.8kV | 6.6kV (7.2kV) 6.35kV | 11kV (12kV) 8.7kV | 15kV (17.5kV)  12kV | 20kV (24kV)
Impulse Level (BIL) kV Peak 60kV 95kV 95kV 125kV
Minimum clearance phase to phase (c) 45mm 75mm 85mm 100mm
Minimum clearance phase to earth (E) 35mm 60mm 75mm 75mm
Minimum clearance between insulating boots (Z) 12mm 12mm 12mm 15mm

Minimum Air Clearances for HV Terminations in Cable Boxes in Accordance with BS 164 Class A
Maximum System Voltage, Phase to Phase (kV) 6.6kV 7.2kV 11kV 12kV 24kV 33kV 36kV
Minimum Air Clearance Between Live Metal ‘A’ (mm) 90 127 242 356
Minimum Air Clearance Between Live Metal and Earth ‘B’ (mm) 65 75 140 222

See also  ➡  11kV Terminations 3 Core | 11kV Terminations Single Core | 33kV Terminations 3 Core | 33kV Terminations Single Core

Thorne & Derrick distribute the complete range of Cable Terminations for medium/high voltage power cables from stock for 11kV/33kV/66kV.

Terminations 11kV 33kV

Cable Glands | Screen Earth Kits | Cable Lugs (Crimp Shearbolt) | Bushing Boots | 11kV 33kV

Data Sheets