Ahem, please forgive me NFPA, for I have sinned... Wired the 120V service to my shop building in ring topology. Single 240V/40A breaker to the ring where enters building, and each 20A outlet has a 12A 'T' hi-break line fuse. The only hi-X load is small drill press, so no motor issues.
The 240V building wiring is 'traditional', and was done by a boring and competent electrician. Have also seen ring wiring in Ireland, which was probably one of Cromwell's programs Brian -----Original Message----- From: Ralph McDiarmid [mailto:[email protected]] Sent: Thursday, December 15, 2016 10:30 AM To: [email protected] Subject: Re: [PSES] British question, about a BS1363 plug-in power supply An interesting design philosophy which has benefits, but it seems to rely on pluggable appliances having an appropriate size fuse in their cordage. You could for example wire an entire house with 3 or 4 of these circuits, rather than a panel full of circuit breakers so common in N.Am Ralph McDiarmid Product Compliance Engineering Solar Business Schneider Electric *Please consider the environment before printing this e-mail -----Original Message----- From: John Woodgate [mailto:[email protected]] Sent: Monday, December 12, 2016 1:50 PM To: Ralph McDiarmid <[email protected]>; [email protected] Subject: RE: [PSES] British question, about a BS1363 plug-in power supply A 32 A breaker connects to a loop of 2.5 mm^2 3-core cable (line, neutral and protective). A large number (there is a limit but it's complicated) of 13 A wall outlets can be connected to this ring, relying on diversity to keep the total current below 32 A. With best wishes DESIGN IT IN! OOO - Own Opinions Only www.jmwa.demon.co.uk J M Woodgate and Associates Rayleigh England Sylvae in aeternum manent. -----Original Message----- From: Ralph McDiarmid [mailto:[email protected]] Sent: Monday, December 12, 2016 7:34 PM To: [email protected] Subject: Re: [PSES] British question, about a BS1363 plug-in power supply What's a "ring circuit" ? Ralph McDiarmid Product Compliance Engineering Solar Business Schneider Electric From: Richard Nute [mailto:[email protected]] Sent: Saturday, December 03, 2016 12:01 PM To: [email protected] Subject: Re: [PSES] British question, about a BS1363 plug-in power supply I understood the fuse in the U.K. plug was to protect the power cordage. In the U.K., outlets are supplied by a ring circuit rather than a branch circuit, therefore the power cord could exceed its ampacity (a U.S.A. term). So, if no power cord, no need for a fuse in the plug. I wonder if the power supply has a fuse to protect the power supply. If so, would this count as the plug fuse? Rich From: John Woodgate [mailto:[email protected]] Sent: Saturday, December 03, 2016 5:01 AM To: mailto:[email protected] Subject: [PSES] British question, about a BS1363 plug-in power supply I received a 5 W SMPS plug-in power supply as part of a multi-unit product. It has interchangeable pins for EU, US, Australian and UK sockets, but it has no fuse. I think this is illegal and intend to notify Trading Standards, as the overall product is marketed by a prominent European company and is widely offered on the Internet. Is there any exemption at all for the requirement that a BS 1363 plug in any form must have a fuse? - ---------------------------------------------------------------- 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]>
