Ian Are these harnesses and connectors:
1. within the part of the enclosure that needs to be a Fire Enclosure due to presence of PS3 circuits, 2. or are they in other parts of the enclosure that doesn't need to be a Fire Enclosure, as all circuits are PS1, but it just happens that the enclosure material is the same? If (a), then there are restrictions on them as explained in PD IEC/TR 62368-2:2015 6.4.6 Control of fire spread in a PS3 circuit Source: IEC 60950-1 Rationale: There are two basic requirements to control the spread of fire from PS3 circuits: a) use of materials within the fire enclosure that limit fire spread. This includes the same requirements as for components in PS2 circuits and includes a requirement from IEC 60950-1 to address all combustible materials that are found within the fire enclosure; b) use fire-containing enclosures - Product enclosures will have a design capable of preventing the spread of fire from PS3 circuits. The criteria for fire enclosures is based on the available power. Rationale: PS3 sourced circuits may contain a significant amount of energy. During single fault conditions, the available power may overwhelm the safeguard of material control of fuels adjacent to the fault or any consequential ignition source making a fire enclosure necessary as part of the supplementary safeguard. A fire enclosure and the material controls constitute the necessary supplementary safeguard required for a PS3 circuit. If (b), then my understanding is that that part of the enclosure is not acting as a "fire enclosure", so the rules don't apply to those harnesses providing they are suitably separated from the volume requiring a Fire Encloure Regards Charlie Charlie Blackham Sulis Consultants Ltd Tel: +44 (0)7946 624317 Web: https://sulisconsultants.com/ Registered in England and Wales, number 05466247 From: McBurney, Ian <[email protected]> Sent: 04 February 2020 13:55 To: [email protected] Subject: [PSES] 62368-1 fire enclosure Dear colleagues. I have a question regarding the flammability rating of components located within a fire enclosure. We have been told by a safety approval engineer that under clause 6.4.6 of 62368-1:2014 that all combustible material within a fire enclosure and not part of a PS2 or PS3 circuit must have be V-2 or better flammability rating. For example, internal harnesses & connectors which carry low level signals between PCBs and do not carry supply voltages must have a rating of V-2 or better. Does this mean that any component within a fire enclosure regardless of location must have a minimum flammability rating of V-2 or pass the convoluted Annex S.1 test? Many thanks in advance; Ian McBurney Lead Compliance Engineer Allen & Heath Ltd. Kernick Industrial estate, Penryn, Cornwall. TR10 9LU. UK. Tel: 01326 372070 Email: [email protected]<mailto:[email protected]> Allen & Heath Ltd is a registered business in England and Wales, Company number: 4163451. Any views expressed in this email are those of the individual and not necessarily those of the company. - ---------------------------------------------------------------- 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]<mailto:[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)<http://www.ieee-pses.org/list.html> List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <[email protected]<mailto:[email protected]>> Mike Cantwell <[email protected]<mailto:[email protected]>> For policy questions, send mail to: Jim Bacher <[email protected]<mailto:[email protected]>> David Heald <[email protected]<mailto:[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]>
