In general, and for UL and CSA in particular, crimped terminals are evaluated for the number, size, stranding and types of wire under the crimp.
In most cases, only single wires are evaluated, unless the manufacturer specifies that they want additional testing. Wire sizes are critical for any particular crimp design. Too large and all strands might not consolidate well under the crimp or might prevent adequate “squish” of the crimped joint and the crimp will fail. Too small and the crimp will never hold. Either case could serve sources of risk of fire and electric shock. For UL standards, the default stranding is Class B. Other stranding counts require additional evaluation. I suspect, but have not confirmed, the same is true for CSA standards. It is not necessarily true that the more strands these better, since too many strands can form a poor crimp and the crimp tool or the crimp itself can cut or nick strands, which is not a good result. (I have asked both UL and CSA about decimating strands to get a wire size to fit into a connector crimp and was told this was unacceptable. An understandable response.) Copper is the default wire type used for evaluation. Evaluations using aluminum conductors (or anything more exotic) must be done separately. There is no magic method to find crimp terminals that are safety certified for multiple conductors under a crimp. They do exist, but it requires creative internet searches and contacting suppliers. Make certain you get copies of their certification test reports to verify any claims. Regards, Peter Tarver The information contained in this message may be privileged and confidential. It is intended to be read only by the individual or entity to whom it is addressed or by their designee. If the reader of this message is not the intended recipient, you are on notice that any distribution of this message, in any form, is strictly prohibited. If you have received this message in error, please immediately notify the sender and delete or destroy any copy of this message! - ---------------------------------------------------------------- This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <emc-p...@ieee.org> All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <sdoug...@ieee.org> Mike Cantwell <mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher: <j.bac...@ieee.org> David Heald: <dhe...@gmail.com>
