The code actually writes about 125% for breaker rating versus continuous current. And so, 80% of breaker rating for 'continuous loads' (3 hours) in the NEC and CEC, unless the breaker is Listed for 100% of its rating. (210.20 in the 2014 NEC).
I generally despise rules of thumb like this, but the rule goes way back in the code. Anybody know where it came from? You won't find it in any part of IEC 60364-4-43. Apparently, the NEC 'code' was derived originally from the IEC. Ralph McDiarmid Product Compliance Engineering Solar Business Schneider Electric From: Pete Perkins [mailto:[email protected]] Sent: Thursday, September 14, 2017 9:55 PM To: [email protected] Subject: [PSES] power strip details Esteemed colleagues, Here in North America a domestic or commercial multi-outlet power strip would be cord connected thru a duplex outlet protected by a 15A (or sometimes 20A) circuit breaker. The max load allowed in the circuit by the US NEC would be (80% of 15A) 12A for the total load (or 80% of 20A) 16A on the 20A breaker. Note that the US NEC requires that any device plugged into a duplex outlet must not use the full load capacity of the circuit - 20% must be left for the other outlet's load. Trying to understand the loading basis for a Euro power strip. Is the usual protection a 10A breaker? And would the power strip be rated and evaluated at that load level? What other considerations come into play here? How about a UK power strip. The usual protection is the 13A fuse in the power plug (altho smaller values seemed to be used also). Would the power strip be rated and evaluated at that load level? What other considerations come into play here. For a Japanese power strip what is the normal breaker protection for the installed circuit? What would be the max rated load for the power strip? What other considerations come into play here also? Looking forward to your replies on this issue. :>) br, Pete Peter E Perkins, PE Principal Product Safety & Regulatory Affairs Consultant PO Box 23427 Tigard, ORe 97281-3427 503/452-1201 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]>
