Hi Charles, UL 60950-1 Annex NAE 3.2.5 states that the power cord length must be between 1.5 and 4.5 meters. The 4.5 meter maximum is from NFPA 70 Article 645.5(B). Although Annex NAE states that the 1.5 meter minimum also comes from the NEC, I can't find it. I may just be missing it. I realize that I'm not answering your question well, or at all. I've only pushed the question back from UL to the NEC.
The historic reason for having a minimum cord length is to reduce the risk of the end user connecting products through extension cords. The intention is that the cord should be long enough to reach an outlet on its own. Generally, NRTLs will not allow a shorter cord. However, there are some exceptions. If your product has an external power supply, UL will consider the length of the AC cord and DC cord together. Most laptop computers now ship with an AC cord far shorter than 1.5 meters for this reason. If the specific use of a product is such that a shorter cord would improve safety, you can try to argue your point. However, this will be a tough process. You may have to work with a senior engineer at your NRTL to find a rationale that they will accept. NRTLs will accept shorter cords for specialized equipment that is intended to be mounted near a receptacle. Regards, Ted Eckert Compliance Engineer Microsoft Corporation [email protected]<mailto:[email protected]> The opinions expressed are my own and do not necessarily reflect those of my employer. From: Grasso, Charles [mailto:[email protected]] Sent: Tuesday, August 5, 2014 6:22 PM To: [email protected] Subject: [PSES] Question on power cord length Hello all, UL6950 and UL60065 both restrict the power cord length to 1.5m.Does anyone know the reason for this length restriction and (more importantly) does anyone know of exceptions that will allow for a shorter cord? Thanks in advance Carles Grasso - ---------------------------------------------------------------- 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 <[email protected]<mailto:[email protected]>> 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)<http://www.ieee-pses.org/list.html> List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <[email protected]<mailto:[email protected]>> Mike Cantwell <[email protected]<mailto:[email protected]>> For policy questions, send mail to: Jim Bacher <[email protected]<mailto:[email protected]>> David Heald <[email protected]<mailto:[email protected]>> - ---------------------------------------------------------------- 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 <[email protected]> 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 <[email protected]> Mike Cantwell <[email protected]> For policy questions, send mail to: Jim Bacher: <[email protected]> David Heald: <[email protected]>
