All Thanks for the very useful comments on Maximum transient voltage on naval ships
I have another question 😊 Clause B4.4 requires clearance and creepage distances for functional insulation to be overloaded PD IEC/TR 62368-2:2015 says: Rationale: The use of a functional insulation is only acceptable when the circuit does not exceeds its limits of its class under normal and abnormal operation conditions and single fault conditions of a component not serving as a safeguard (see 5.2.1.1 and 5.2.1.2). Otherwise a basic insulation/safeguard would be required. If the functional insulation possesses a certain quality (clearance, creepage distances, electric strength) comparable to a basic safeguard, it is acceptable to omit short-circuit. This cannot be compared to the short-circuiting of a basic safeguard as required in B.4.1, because this basic safeguard is a required one, while the added quality of the functional insulation is not required. If the short-circuiting of this functional insulation with added quality would lead to a changing of the class, the functional insulation was wrongly chosen and a basic safeguard would have been required Does that mean Functional insulation should only be short circuited if it could result in an ES1 circuit becoming ES2, or PS2 becoming PS2? Or would functional insulation be short circuited to check whether it might result in excessive power dissipation that might lead to fire etc? The product has a metal fire enclosure, so all internal circuits are considered PS3 without segregation into different PS Best regards Charlie Charlie Blackham Sulis Consultants Ltd Mead House Longwater Road Eversley RG27 0NW UK Tel: +44 (0)7946 624317 Email: [email protected]<mailto:[email protected]> Web: https://sulisconsultants.com/ Registered in England and Wales, number 05466247 - ---------------------------------------------------------------- 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]>
