Dear Doug & John, Thanks for your valuable comments.
In conclusion, the TV with pc mode should be tested to both EN60065 & EN60950 standards. The current debating is that the market does not have too many EN60065 compliant SMPSs available for selection. EN60950 compliant SMPSs are many largely because they design for monitor and pc. There are a clear differences in C & C specs between EN60950 & EN60065 standards. As you know, the existing SMPSs for pc and monitor are very compact. If they need to comply with EN60065 standard, they need to redesign the pcb and components layouts. How come a EN60950 compliant SMPS is considered unsafe to EN60065? What are the major differences to make the unit unsafe in TV mode? It seems the discussion exceeds the technical nature and falls into logic nature. Any comments in this area are appreciated. Thanks and regards, Raymond Li OSA Ltd. "Doug Massey" <[email protected]> Sent by: [email protected] 21/01/04 07:11 AM Please respond to "Doug Massey" <[email protected]> To "'Tyra, John'" <[email protected]>, <[email protected]> cc Subject RE: Safety standard for LCD/PDP TVs Hi John – Doesn’t come much more plainly stated than that! Thanks for the correction – I’m more familiar with 60950 than with 60065, and I certainly don’t follow all of the OSM decisions for the standard – so I do appreciate the correction. More reason to apply 60950 to the TV that has a ‘PC mode’ and incorporates a 60950-recognized SMPS. Back to Raymond’s original post, I would think that the TV without ‘PC mode’ CANNOT be evaluated to 60950, as it would fall clearly under the scope of EN 60065, and not under 60950. For the unit with ‘PC mode’, I assume that it could be defined as a multimedia device per IEC Guide 112, and could therefore be evaluated to the 60950 standard, if so desired. I’m also not knowledgeable enough to know whether one can make an assumption that spacings within the power supply evaluated to 60950 would meet the spacings required by 60065 – just musing about how much ‘retesting’ would need to be performed on a 60950 SMPS for use in a 60065 product. I wonder what ‘specific data’ the agency is looking for, in order to decide that the power supply does not need retesting per 60065…sounds like the best Raymond can do is get the 60950 report for the power supply and submit it to the agency evaluating the TV, and hope for the best. Thanks John - Doug Massey Product Safety Engineer Advanced Compliance Solutions From: Tyra, John [mailto:[email protected]] Sent: Tuesday, January 20, 2004 5:44 PM To: 'Doug Massey' Cc: [email protected] Subject: RE: Safety standard for LCD/PDP TVs Hello Doug... I agree with everything you say except the statement about 60950 power supplies being accepted for use in an end product being evaluated to 60065 without retesting. The last CENELEC OSM Decisions I received 7/2002 have a statement on page three which states the following: "An IEC950 SMPS cannot be used in an IEC65 device without retesting" While the two standards have many similarities there are several small conflicts........as an example IEC60065 requires a mains connected fuse relied upon for safety to comply with IEC60127. I have not worked with IEC60950 in 4-5 years but I don't believe this is required by that standard, especially for service only replaceable fuses. In any case I believe it is possible an Agency may want to at least review the IEC60950 SMPS for use in a IEC60065 end product application...CENELEC OSM Decisions also note that if there is sufficient data available the supply may need a complete retest......We don't use SMPS but a UL Engineer confirmed this for me about a year ago......... regards, John Tyra Product Safety and Regulatory Compliance Manager Bose Corporation The Mountain, MS-450 Framingham, MA 01701-9168 Phone: 508-766-1502 Fax: 508-766-1145 [email protected] From: Doug Massey [mailto:[email protected]] Sent: Tuesday, January 20, 2004 3:07 PM To: [email protected]; [email protected] Subject: RE: Safety standard for LCD/PDP TVs Hi Raymond, IEC Guide 112 is used for guidance in determining the appropriate standard to be used for multimedia equipment. It allows either standard to be used, if the equipment can be defined as multimedia. Only one standard must be applied (not both). I disagree that a TV can be evaluated under the 60950 standard, just because the power supply inside was evaluated to 60950 - this logic does not follow the scope of either standard. The appropriate course is to evaluate the TV per 60065 (this is clearly in the scope of 60065), which allows power supplies meeting the requirements of 60950 to be used without additional evaluation. If the TV can meet the definitions of multimedia equipment given by IEC Guide 112, I would always choose 60950 - personal preference, mainly, but also because 60950 would (most likely) not require humidity preconditioning prior to hi-pot testing, saving me time and expense. These standards are merging in the not-very-distant future, by the way. IEC Guide 112 is available for download from the IEC web store, and costs just a few bucks. Regards, Doug Massey Product Safety Engineer Advanced Compliance Solutions From: [email protected] [mailto:[email protected]] On Behalf Of [email protected] Sent: Sunday, January 18, 2004 12:21 AM To: [email protected] Subject: Safety standard for LCD/PDP TVs This type of products may have PC mode or not. Most of manufacturers are applying EN60950 safety standard rather than EN60065 safety standard for the primary reason of the SMPS available on the market that used for monitor. For TV without pc mode, if the product passes EN60950, can it be considered to comply with LVD 73/23/EEC. For TV with PC mode, both EN60065 and EN60950 have to be complied or only one is sufficient? Your advice is appreciated. Thanks and regards, Raymond Li OSA Ltd.
