On the heels of my IP question, here's one on NEMA 250. Or maybe it's just a comment since I'm sure it can't be changed.
For NEMA 3 enclosures, the way the optional coverages is lumped seems funny to me... - NEMA 3 without any suffix protects against access, against falling dirt and windblown dust, protects against rain, sleet, and snow, and is undamaged by formation of external ice - add R = this removes protection against windblown dust and lets you say "rainproof" - add S = external mechanisms remain operable when ice laden, it adds back in the windblown dust requirement, and it's mutually exclusive of the "R" suffix - only 3R and 3RX are allowed to be ventilated, I guess since it is assumed that you can't meet the dust requirement with a ventilated unit. Therefore a ventilated product cannot have an external mechanism that is proven to be operable even when ice laden. We can make the claim, but we can't back it up with a NEMA rating because 3S and 3R are mutually exclusive. I would have set this up with a series of optional coverages each of which addresses only one feature - raintight, rainproof, ice formation does not cause damage, ice formation does not prevent operation of external mechanisms, extra corrosion protection or not, etc. Does anyone have any insight into this? Thanks, Jim Eichner, P.Eng. Manager - Compliance Engineering Xantrex Technology Inc. e-mail: [email protected] web: www.xantrex.com Any opinions expressed are those of my invisible friend, who wants products to have a NEMA rating indicating whether or not your tongue will stick to them when they are covered in frost Confidentiality Notice: This email message, including any attachments, is for the sole use of the intended recipient(s) and may contain confidential and privileged information. Any unauthorized review, use, disclosure or distribution is prohibited. If you are not the intended recipient, please contact the sender by reply e-mail and destroy all copies of the original message. - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. Website: http://www.ieee-pses.org/ To post a message to the list, send your e-mail to [email protected] Instructions: http://listserv.ieee.org/request/user-guide.html 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] All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc ______________________________________________________________________ This email has been scanned by the MessageLabs Email Security System. For more information please visit http://www.messagelabs.com/email ______________________________________________________________________
