What about the DB connectors on the rear, like the RS232, which are user-accessible and connected to secondary circuits?
The grounded chassis doesn't help in that case and so the two levels of protect from primary-secondary must then come from Reinforced insulation. If you could not get your fingers on those pins, then the second level of protection would be provided by the inaccessibility. No true in the case of an RS232 DTE connector. Ralph McDiarmid, AScT Compliance Engineering Group Xantrex Technology Inc. www.xantrex.com tel: (604) 422 2622 fax: (604) 420 1591 From: douglas_beckw...@mitel.com [mailto:douglas_beckw...@mitel.com] Sent: June 26, 2003 8:45 AM To: Peter Horvat Cc: 'emc-p...@ieee.org'; owner-emc-p...@majordomo.ieee.org Subject: Re: Dielectric withstand voltage for power supplies Hello Peter PC power supplies are Class I devices. By definition in EN60950 clause 1.2.4.1 the power supply only requires basic insulation between Primary and earth, primary and secondary, and must be provided with a protective earth. The basic insulation + protective earth provides the two levels of protection for the user. The dielectric strength requirements are 1500Vac for basic, and 3000Vac for reinforced. Class 1 power supplies only require 1500Vac (2121VDC)(basic insulation). In your case, this is not a problem, the user has 2 levels of protection. The problem becomes more complicated if you are providing connection to the telecommunications network in Norway and Sweden. There are supplies on the market that provide reinforced between primary and secondary, but they are usually more expensive. Regards Doug Beckwith |--------+---------------------------------> | | Peter Horvat | | | <peter...@cae.com> | | | Sent by: | | | owner-emc-pstc@majordom| | | o.ieee.org | | | | | | | | | 06/26/03 09:36 AM | | | Please respond to Peter| | | Horvat | | | | |--------+---------------------------------> >--------------------------------------------------------------------------- -------------------------------| | | | To: "'emc-p...@ieee.org'" <emc-p...@ieee.org> | | cc: | | Subject: Dielectric withstand voltage for power supplies | >--------------------------------------------------------------------------- -------------------------------| Hi, Can anyone explain the electrical strength requirements for PC power supplies (input/output) to comply with EN60950. Does basic insulation or reinforced insulation apply? Particularly in the case that the PC peripherals and male D-sub connectors (that can come in contact with users) are only basic insulated PS suitable. I found that most power supplies available on the market are only tested at 1500VAC between in/out. Thank you in advance for your help, Peter Horvat CAE Inc. This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
