Bushing Boots 11kV Switchgear & Transformer Cable Boxes | Nexans FB1 & FB2
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.
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.
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
➡ 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|
Thorne & Derrick distribute the complete range of Cable Terminations for medium/high voltage power cables from stock for 11kV/33kV/66kV.