>From IEC 62368-1 (FDIS): Groups RG-1 and RG-2 according to IEC 62471 belong to exempt group--> no hazard
The different classes are defined in IEC 62471. Low power application of LEDs are in the exempt group. UV radiation from general purpose incandescent and fluorescent lamps, with ordinary glass envelopes, are taken as RS1. EXAMPLE RS1 LEDs are those used as: indicating lights; infra-red devices such as used in home entertainment devices; infra-red devices for data transmission such as used between computers and computer peripherals; optocouplers; and other similar low power devices. NOTE 1 If optical radiation is broadband visible and lR-A radiation and the luminance of the source does not exceed 104 cd/m2, it is expected that the radiation does not exceed the exposure limits given in 4.3 of IEC 62471:2006 (see 4.1 of IEC 62471:2006). For UV-C limits (wavelengths between 180 nm and 200 nm), the value of IEC 62471 for 200 nm is used. Best regards, Bostjan -----Original Message----- From: John Woodgate [mailto:[email protected]] Sent: Monday, January 13, 2014 11:12 PM To: [email protected] Subject: Re: [PSES] LED Indicator Safety In message <64D32EE8B9CBDD44963ACB076A5F6ABB0267F68D@Mailbox-Tech.lecotech.local>, dated Mon, 13 Jan 2014, "Kunde, Brian" <[email protected]> writes: >They want the LED itself to be bright so it shines through the Light >Pipe with good intensity. There is a question of whether the light pipe is well designed and whether the LED is coupled to it correctly. While the principle of the light pipe is well known, it does need to be designed correctly in order to be efficient. >LED brightness is a relative thing. If your product is used in a >relatively dark ambient room the indicators appear too bright (get out >the black tape). But it if is installed in a very bright room, then you >get complaints that the customer cannot read the indicators. You cannot >win. > Bring back the CdS cell used in LED bedside radios to control the display brightness oh, no, we can't because the 1 mg of cadmium kills at 100 m range. (;-) But there are silicon-based substitutes now. > > >The LED in question is only rated 150mcd (millicandelas) which >doesn’t seem very high to me. Is there a “Light Intensity” level >in which you have to be concern about being too bright? I would like to >just give Engineering a value and tell them to keep their LEDs below >that level and you will have no problem. At one time, LEDs were classified as 'sort-of' lasers and there were very stringent requirements imposed. These were relaxed later. There is relevant information in IEC/EN 60950-1 4.3.13.5.2 (specifically in EN 60950-1:2006+A12:2011). You probably need to look at these: IEC 62471 Edition 1.0 (2006-07-26) Photobiological safety of lamps and lamp systems IEC/TR 62471-2 Edition 1.0 (2009-08-06) Photobiological safety of lamps and lamp systems - Part 2: Guidance on manufacturing requirements relating to non-laser optical radiation safety -- OOO - Own Opinions Only. With best wishes. See www.jmwa.demon.co.uk Nondum ex silvis sumus John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK - ---------------------------------------------------------------- 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]> - ---------------------------------------------------------------- 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]>
