Termate’s range of through bushings are designed to allow conductors to pass through enclosure walls, enabling form 3 or form 4 enclosure separation in compliance with BS EN IEC 61439-2.

The both designs accept up to four different conductor sizes. From 3 mm and 10 mm thick. Insulated boots for both sizes are available for added IP protection.


3D Render of Termate's B4-30 Busbar Bushing


3D Render of Termate's B4-50 Busbar Bushing
Part Number3D ModelConductor sizes (mm)Ue (AC/DC)Ui (AC/DC)Uimp
B4-30B4-30 STEP file20×3, 20×4, 30×5, 30×10690 V690 VkV
B4-50B4-50 STEP file25×5, 20×10, 40×10, 50×10500 V500 VkV

B4-30 Bushings—Punching Details

B4-50 Bushings—Punching Details

Termate B4-50 Punching/Fixing diagram; showing 4×M6 screw holes set on a 47×47mm square, surrounding a 57mm diameter punch

Common Technical Information (B4-30 & B4-50)

  • Material: Glass Reinforced Polyamide 6.6
  • Conductor Temp.: 140 °C
  • Flammability: UL 94 V-0
  • Glow Wire: 960 °C

In line with the limits set out in IEC 61439, insulating components in contact with conductors may be required to continuously operate at an average of 140 °C (max 145 °C).

This range of products meets the requirement, the material for them being assigned thermal class F established using methods similar to IEC 60085




Part Number3D ModelDescriptionMax. Cable size (mm²)
B4-30BOOTB4-30BOOT STEP fileAngled Boot for B4-301×300
B4-30S-BOOTB4-30S-BOOT STEP fileStraight Boot for B4-301×300
B4-50BOOTB4-50BOOT STEP fileAngled Boot for B4-501×500

Boot Properties

  • Boot Material: Black PVC
  • Operating Temp.: Max. 90 °C continuous
  • Flammability: UL 94 V-0
  • Glow Wire: 650 °C

B4-30 Bushings—Versatility

B4-50 Bushings—Versatility