Glossary · Electrical engineering and control panels
Wire ferrule
Also known as: Ferrule, Bootlace ferrule, End sleeve
German: Aderendhülse
In control panel building, a wire ferrule is a metal sleeve, often with a plastic collar, that is crimped onto the stripped end of a stranded conductor so all strands are held together for a reliable connection in a terminal.
- Control panels
In one sentence
A wire ferrule is a crimped metal sleeve on a stranded wire end that holds all strands together for a reliable terminal connection.
Example
All 0.75 mm² control wires in the cabinet are fitted with insulated ferrules crimped with a square crimping tool before they are inserted into the terminals.
How it applies
- Engineering: Whether ferrules are required depends on the terminal design and manufacturer approval; many terminals allow stranded wire with or without ferrules. Color codes of collars vary between standards and manufacturers, so specify the system used. In German practice, DIN 46228 defines common ferrule types.
- Installation: Use the correct size and a suitable crimping tool; a badly crimped ferrule can cause loose connections and heating.
- Documentation: Panel-building specifications should state when ferrules are used, which color code applies and which tools are approved. In US English, "ferrule" is the usual term; "bootlace ferrule" is common in British English.
Wire ferrule vs. cable lug
A ferrule is inserted into a clamping terminal. A cable lug is crimped onto larger conductors and bolted to a stud or busbar.