In our detachable cord connected products, we use American power cords with black, white, green wires on 120V units which are UL Listed, CSA Certified; and European cords with brown, blue, green/yellow wires on 230V units. (As an aside, note how UL and CSA choose to ignore the UL1950 requirement that earthing conductors be green/yellow in this case - or maybe they don't regard the detachable mains cord as part of the UL1950 product !)
Inside our products, where we use 3 core cable for ac distribution, we use the European colors. Where we use individual wires, e.g. around the on/off switch, fuse, etc, we usually use black and white hook-up wire. There were moves some time ago in the British trade association FEI, to get requirements for internal ac wiring coloring to be included in IEC 950, but it died a death. Have just noticed the announcement of the publication of IEC 60446, Edition 3, February 1999 : Basic and safety principles for man-machine interface, marking and identification - Identification of conductors by colours or numerals. I'm afraid I don't have a copy - and won't be buying one either, but I've made a note to have a look at it in the BSI library next time I'm at a BSI meeting. The last draft I saw (16/367/CDV) required the neutral conductor to be light blue. However, I did make the following comments to BSI 2 years ago (and they seem to have been ignored !!) : - "Note 2 in clause 3.2.2 reads "In the United States of America and Canada, the colour identification white for the mid-wire or neutral conductor is used as equivalent to the colour identification light blue." This note is informative, and since the USA and Canada are unlikely to adopt the use of light blue for neutral (other than in power cords), it would be preferable to change every reference to "light blue" in Clause 3.2.2 to read "light blue or white", and delete Note 2. Clause 3.2.3 reads "The colours light blue, black and brown are preferred for conductors of AC systems". In view of my comment above, and since the colour black as used in the USA for line has been included, this should be changed to read "The colours light blue, white, black and brown are preferred for conductors of AC systems". Whether the word "preferred" should be used is open to question !" You'll see that I feel bound to put in my 2c worth of comment on any standard which happens to "float" past my desk. It is the only way that we can influence what is going on out there - if you you don't participate, and attempt to influence the content of standards, you can't complain about the standards you get stuck with. To make my point - we only have the dreaded IEC 61000-3-2 harmonics standard because the majority of countries voted for it !! And now I'll get down from my high horse and creep back to work......... John Crabb, Development Excellence (Product Safety) , NCR Financial Solutions Group Ltd., Kingsway West, Dundee, Scotland. DD2 3XX E-Mail :john.cr...@scotland.ncr.com Tel: +44 (0)1382-592289 (direct ). Fax +44 (0)1382-622243. VoicePlus 6-341-2289. --------- This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: "unsubscribe emc-pstc" (without the quotes). For help, send mail to ed.pr...@cubic.com, j...@gwmail.monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
