I assume we are discussing the NEMA 5-15 or 5-20 outlets. As with most things in life, there are different ways to view this issue. Let's consider the condition where the weight of the cord, or something pulling down on the cord, starts pulling it down out of the wall outlet.
On one hand, installing the ground pin up means that if the plug is not fully inserted, or if it's being pulled down, the ground connection is exposed. As noted, any conductive object falling hits this ground pin. On the other hand, anything pulling down on the cord will pull the ground pin away from its connections. The pin is longer to try to ensure it makes first and breaks last. However, if the plug is pulled at a severe angle, there is a risk that the ground connection breaks before line and neutral. If ground is installed down, the more common downward pull on cords results in line and neutral breaking first while ground remains connected. I'll admit that I haven't searched to see if there is data indicating one of these is a more common problem than the other. Much of the world has figured out recessed sockets as Mr. Woodgate notes, and partially insulated line and neutral pins are also common. I recognize that there is little to be done to change the American plug system. Ted Eckert The opinions expressed are my own and do not necessarily reflect those of my employer. ________________________________ From: Douglas Powell <[email protected]> Sent: Friday, June 12, 2026 7:42 AM To: [email protected] <[email protected]> Subject: [EXTERNAL] [PSES] Friday Question - in the USA, ground pin down or gorund pin up? At my local medical offices, I took notice that all the electrical outlets in the facility have been installed with Ground Pin Up and not the conventional Ground Pin Down. So I investigated. Ostensibly, this is to avoid the accidental and foreseeable event of a tray of other conductive objects falling across the line and neutral. While this article actually says it does not matter, I feel that it does. I've seen exactly this accidental scenario occur in real life with a ball chain necklace. https://www.archtoolbox.com/outlet-ground-pin-up-or-down/ ~Doug Douglas E Powell Founder & Principal Consultant Vertex Compliance Consulting<https://bit.ly/45BXk3Y> (VertexCC) Laporte, Colorado, USA LinkedIn<https://www.linkedin.com/in/realdougpowell/> Colorado Registered Business | Entity ID: 20191778678 (UTC-06:00, US-MDT) ________________________________ 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: https://www.mail-archive.com/[email protected]/ Website: https://ewh.ieee.org/soc/pses/ Instructions: https://ewh.ieee.org/soc/pses/list.html (including how to unsubscribe)<https://ewh.ieee.org/soc/pses/list.html> List rules: https://pses.ieee.org/wp-content/uploads/2024/12/EM-PSTC-List-Rules.pdf For help, send mail to the list administrators: Mike Sherman at: [email protected]<mailto:[email protected]> Rick Linford at: [email protected]<mailto:[email protected]> For policy questions, send mail to: Jim Bacher at: [email protected]<mailto:[email protected]> ________________________________ To unsubscribe from the EMC-PSTC list, click the following link: https://listserv.ieee.org/cgi-bin/wa?SUBED1=EMC-PSTC&A=1 - ---------------------------------------------------------------- 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: https://www.mail-archive.com/[email protected]/ Website: https://ewh.ieee.org/soc/pses/ Instructions: https://ewh.ieee.org/soc/pses/list.html (including how to unsubscribe) List rules: https://pses.ieee.org/wp-content/uploads/2024/12/EM-PSTC-List-Rules.pdf For help, send mail to the list administrators: Mike Sherman at: [email protected] Rick Linford at: [email protected] For policy questions, send mail to: Jim Bacher: <[email protected]> _________________________________________________ To unsubscribe from the EMC-PSTC list, click the following link: https://listserv.ieee.org/cgi-bin/wa?SUBED1=EMC-PSTC&A=1
