Thank you for the correction, Brian. I referenced the wrong standard. UL 1363 is the relocatable power tap standard. UL 1310 is for Class 2 Power Units and doesn't address this issue.
Regards, Ted -----Original Message----- From: Brian O'Connell [mailto:[email protected]] Sent: Thursday, January 27, 2011 9:35 AM To: [email protected] Subject: Re: Socket-outlet current rating on the direct plug-in equipment Perhaps UL1363 for Relocatable Power Taps? Brian -----Original Message----- From: [email protected] [mailto:[email protected]]On Behalf Of Ted Eckert Sent: Thursday, January 27, 2011 9:25 AM To: [email protected] Subject: RE: Socket-outlet current rating on the direct plug-in equipment Hello Mark, For the United States, the maximum limit is based on the standard used for testing. The National Electrical Code only allows the continuous load on a branch circuit to be 80% of the rating of that circuit. For a 15 A circuit, you have a 12 A limit. For most product standards where an accessory outlet is allowed, this rule will be enforced and UL will require a maximum rating of 12 A on a 15 A outlet. However, products tested under UL 1310 are Relocatable Power Taps. They are considered a temporary extension of the branch circuit and are not considered a load device. UL will allow these products to have outlets rated for the full current. There are likely a few other product standards that have the same allowance. The difference is subtle, but it comes down to whether the device with the outlet is considered part of the branch circuit or part of the load connected to it. This is a requirement for the United States and Canada, but it does not apply to most of the 220 - 240 V / 50 Hz world. The 80% rule does not apply in most of the world. I would be careful when rating an outlet for less than the maximum current if only because you have no way of preventing somebody from connecting a higher load. If you have a 15 A outlet, your customers can connect anything with a 15 A plug. Text stating "1 A Maximum" won't be noticed or heeded by many people. The wiring to the outlet should either be able to handle the full rating, or you should consider adding an overcurrent protector rated based on the lower output rating. Regards, Ted Eckert Compliance Engineer Microsoft Corporation [email protected] From: [email protected] [mailto:[email protected]] Sent: Thursday, January 27, 2011 7:19 AM To: [email protected] Subject: Re: Socket-outlet current rating on the direct plug-in equipment For the USA, the current rating of the receptacle can be what you want it. I believe you cannot exceed a 35C rise on the face of the receptacle while being tested at rated current. Many of these convenience receptacles are rated 12A vs 15A for this exact reason. Reference UL498, UL498A, UL1310 and UL1786. From: Mark Gandler [mailto:[email protected]] Sent: Wednesday, January 26, 2011 8:41 PM To: [email protected] Subject: [PSES] Socket-outlet current rating on the direct plug-in equipment Hi, if one to sell direct plug-in equipment with build-in socket outlet (air-freshener, night light) what would be appropriate current rating on the socket? Do you have to take into consideration current draw of the product itself, regardless of how small it could be, let's say 0.1A? For example, UK version, based on BS1363, maximum current is 13A. Do you put 12.9A on the socket? and if yes, how practical is it to expect the consumer will follow it to the dot? In general, can standalone sold sockets be rated less than maximum allowed current in each country? do you ever encountered such sockets? Thanks for the inputs any of the above, Mark - ---------------------------------------------------------------- This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. 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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://product-compliance.oc.ieee.org/ Graphics (in well-used formats), large files, etc. can be posted to that URL. Website: http://www.ieee-pses.org/ Instructions: http://listserv.ieee.org/request/user-guide.html 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]>
