Weidmüller has received worldwide certification for a crimped wire-end ferrule for the North American and Canadian region: the connection as a whole has been certified, not the individual components. Underwriters Laboratories certified the system, comprising the wire-end ferrules, together with the hand tools and automatic strippers and crimpers used for the crimping process. The hand-held tools are types PZ4, PZ 6/5, PZ3, PZ6 roto, PZ16 for wire-end ferrules with plastic collars, as well as automatic Crimpex series strippers and crimpers and the CA 100 automatic stripper and crimper.
UL approval applies to all insulated wire-end ferrules belonging to the cross-section range 0.25-50mm2 (AWG 26-1), excluding the 35mm2 (AWG 2) cross-section version insulated wire-end ferrules sold in bulk form.
The classic wire-end ferrule is a tinned copper sleeve, which is placed onto the end of the wire where it is crimped. This means that wire-end ferrules are used to insert the conductor into the connection or terminal compartment without it splitting. Tinning finely stranded wire ends does not afford protection against splitting, because the tin solder or the tinned wire conductor begins to yield under the pressure of the clamping screw. This is not the case when crimping: crimping represents a reliable, permanent electrical and mechanical connection between the wire conductor and the crimp contact. However, it is imperative that the wire conductor (cross-section) and crimping tool are designed to harmonise seamlessly. The wire ends, when fitted precisely with wire-end ferrules, do not break off, even when subjected to vibration loads.
In comparison with non-insulated ferrules, wire-end ferrules with plastic collars offer an enhanced level of electrical safety as well as mechanical stability. Moreover, standardised colour-coded plastic ensures wire conductor cross-sections are easily identifiable. Users are able to choose between the DIN colour code and Weidmüller's colour code. Wire-end conductors with plastic collars provide a flawless, gas-tight connection between the wire conductor and the ferrule. The twin wire-end ferrule is a sleeve with plastic collar into which two cables are fed simultaneously.
Although the plastic was already UL approved, approval still had to be given to the wire-end ferrule as a whole. Now that there is approval for the system comprising wire-end ferrules, hand tools and strippers and crimpers as a whole, there is no obstacle left to worldwide acceptance. For export-oriented companies, this means the lifting of trade and import restrictions currently in force; the UL certificate for the NAFTA (North American, Canadian and Mexican) region therefore opens up market opportunities across the globe.
Weidmüller has a comprehensive range: this includes wire-end ferrules (to DIN 46228, Paragraphs 1 and 4), with and without plastic collars for nominal cross-sections ranging from 0.14mm2 to 50mm2, crimp sets and special tools to strippers and crimpers through to wire-end ferrule boxes, as well as boxes with coloured empty box inserts. For further details, visit the website at www.weidmuller.co.uk.