Single wire seals and cavity plugs: how connectors are sealed

How a single wire seal works

A single wire seal (also called a grommet or wire seal) is a small elastomer seal that is pushed onto the insulated cable and fitted together with the contact. Inside the connector housing it seals the cavity that holds the contact: on the inside against the cable insulation, on the outside against the housing wall.

The fit is decisive: the inner diameter of the seal and the outer diameter of the insulation have to match, otherwise the seal does not seal or cannot be fitted. The manufacturers of the connector systems specify permissible ranges for this.

Cavity plugs for unused cavities

Not every cavity in a connector housing is used. So that unused cavities stay tight as well, they are closed with cavity plugs. Which plugs fit is laid down by the manufacturer of the connector. Some housings work with a common mat seal instead of single wire seals.

What matters when fitting

• The right seal for the cable diameter and the contact system
• The position of the seal on the cable, matched to the stripping length and the crimp
• No damaged sealing lip when the seal is pushed on and crimped
• Cavity plugs in every unused cavity
• Electrical testing and, where required, a leak test

In our production, single wire seals are fitted by machine: on the fully automatic cable processing machine with monitoring of the seal position, and on semi-automatic machines for samples and small lots. More about processing under cable assembly.

Sourcing seals and cavity plugs

Anyone assembling sealed connectors themselves needs contacts, seals and cavity plugs to suit the connector system. These individual components are also available through the distribution site powercable.de. If you want the complete assembly from a single source, we take it on for you.