<[email protected]>, Doug McKean <[email protected]> inimitably wrote: >1. Have any you ever run into something > like this before? > >2. If you have, what did you do about it?
I would say that a safety standard that specifies a cfm rating for a fan is a badly-drafted standard. I would press to get the standard changed. What matters for safety is the temperature that parts can reach. If they are OK, under both normal and fault conditions, the equipment should pass. This is an example of a fundamental principle of prescriptive standardization: 1. If possible, specify performance: it's what matters and is usually easy to verify. 2. If it isn't possible/practicable to verify performance (e.g. if long- term durability is involved), specify construction. 3. If it isn't possible/practicable to specify construction (e.g. because many constructions would be satisfactory), specify design. In this case, specifying performance - temperature rises under normal and fault conditions - is the normal practice. Specifying the cfm is specifying design, and there seems no good reason for that. -- Regards, John Woodgate, OOO - Own Opinions Only. Phone +44 (0)1268 747839 Fax +44 (0)1268 777124. http://www.jmwa.demon.co.uk Why not call a vertically- applied manulo-pedally-operated quasi-planar chernozem-penetrating and excavating implement a SPADE? ------------------------------------------- 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: Michael Garretson: [email protected] Dave Heald [email protected] For policy questions, send mail to: Richard Nute: [email protected] Jim Bacher: [email protected] All emc-pstc postings are archived and searchable on the web at: http://www.rcic.com/ click on "Virtual Conference Hall,"
