I agree with Ilan that two fuses are necessary; almost all of the CE marked (according to EN60950) products that we have designed and/or used (e.g. commercial switching power supplies, ...) have two fuses, one on line and one on neutral. See Tab 2E of EN60950-1. A single fuse could eventually be used only if you are sure that the plant or building protection protection system uses a differential breaker and/or that touch voltage requirements are fullfilled (earth resistance, etc.).
Greetings, ing. Francesco Campedelli R&D - HW Design ALSTOM FERROVIARIA s.p.a. via di Corticella, 75 40128 Bologna - ITALY Ilan, EN60950 requires both overload and earth fault protection. Pluggable products may rely upon the building protection (mains fuses, breakers) to provide line to earth fault protection. If so, a single internal fuse or breaker can protect against overload. Such construction is allowed and is considerd to be safe even if the mains plug is not polarized. Richard Woods Sensormatic Electronics Tyco International From: Ilan Cohen [mailto:[email protected]] Sent: Wednesday, October 29, 2003 8:57 AM To: '[email protected]' Subject: Safety of Schuko CEE7 plug (earthed plug) in Europe? Dear Group I have been looking into the usage of the Continental European Plug also known as Schuko CEE7 plug (earthed plug). It can be inserted into the Wall socket without a way to ensure that line is connected to line and Neutral to Neutral. http://www.interpower.com/scripts/wsisa dll/WService=panel-icl/p80list2.p?w_country=Continental+Europe It presents a technical problem with products, which are protected by one fuse. Typically a fuse is installed in the Line in any product. To be really safe there should be two fusses, one in the line and another in the neutral. Does anyone know the actual regulations in Germany or other countries that started adopting these plugs regarding the number of fusses in the product? There is clearly a safety problem here, which is not being handled properly by safety standards like EN60950 (ITE) or EN60335 (Home appliances). But in the other hand it will be an overkill to request two fusses for products entering the EU (Germany, Italy...) Ilan Cohen Technical Director, Safety & Telecom Divisions I.T.L (PRODUCT TESTING) Ltd. 26 Hacharoshet St, POB 211, Or Yehuda, Israel. Tel 972-3-5339022, Fax 972-3-5339019 [email protected], website: http://www.itl.co.il I-SPEC: The best place on the internet to learn about safety !! http://www.i-spec.com/ (I-Spec is provided free of charge as a service by ITL to the compliance community) CONFIDENZIALE: Questo messaggio e gli eventuali allegati sono confidenziali e riservati. Se vi è stato recapitato per errore e non siete fra i destinatari elencati, siete pregati di darne immediatamente avviso al mittente. Le informazioni contenute non devono essere mostrate ad altri, né utilizzate, memorizzate o copiate in qualsiasi forma. CONFIDENTIAL: This e-mail and any attachments are confidential and may contain reserved information. If you are not one of the named recipients, please notify the sender immediately. Moreover, you should not disclose the contents to any other persons, nor should the information contained be used for any purpose or stored or copied in any form. 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: [email protected] with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: [email protected] Dave Heald: [email protected] For policy questions, send mail to: Richard Nute: [email protected] Jim Bacher: [email protected] 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
