Talk:19-inch rack
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[edit] history
I'm interested in the history of it -- how did telcom racks begin to be used for computers? Who pioneered that, and when did it first happen?
[edit] Old Discussion
- Uhm, all this "incorrect" business makes for a bad entry. How about merging it together? - Jombu
- Thank you for your suggestion! When you feel an article needs improvement, please feel free to make whatever changes you feel are needed. Wikipedia is a wiki, so anyone can edit almost any article by simply following the Edit this page link at the top. You don't even need to log in! (Although there are some reasons why you might like to…) The Wikipedia community encourages you to be bold. Don't worry too much about making honest mistakes—they're likely to be found and corrected quickly. If you're not sure how editing works, check out how to edit a page, or use the sandbox to try out your editing skills. New contributors are always welcome. — Dan | Talk 15:14, 31 Oct 2004 (UTC)
- Is that a reasonable compromise? Alter it if you feel necessary, but I'm not sure about Wiki policy on accuracy. Perhaps the first value should also be an exact one? Estel 14:44, Nov 10, 2004 (UTC)
- Could I request historical content? Who started the 19 inch rack standard, and roughly when did it first appear? Was it a military thing? UK or US or other? Wartime, peacetime? Cheers. Ian.
[edit] HP
This article does a good job of describing the height unit U. Does anybody know anything about the thickness unit HP? -- (unsigned)
- "HP" stands for horizontal pitch. 1HP = 0.2 inches (5.08mm). This is the height of a single card (for example ATCA) when it is mounted vertically (making its height become a measurement on the horizonal axis). A 19 inch rack holds a max of 84 HP, but most subracks use some of the space for controller boards, power FRUs, etc. -- RevRagnarok 13:23, 29 April 2006 (UTC)
[edit] UNITS LINGO
I still cannot understand how tall does 1U has?
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- Each "U" or (unit is equivalent to 1.75 Inches).
Hence 3U =5.25 inches, counting from the bottom inside cutout of the rack.
Hope this helps.
Regards Scotty
[edit] Center to Center Hole Spacing
The article says:
"each hole is part of a horizontal pair with a centre-to-centre distance of 18.3 inches (464.8 mm)."
which I assume must be correct. However, according to my calculations that means they are not quite in the middle of the 0.625" vertical mounting rails, which seems strange. I wonder why tenths of an inch would be used for this measurement when all the others are multiples of one eighth of an inch?
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- Center to Center mounting holes are Nineteen Inches...Hence a Nineteen inch rack industry standard for mounting nineteen inch rack mount equipment.
Regards, Scotty
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- No - the original comment was correct - screw centre to centre is 18.3 inches. The panels on the equipment, which extand to the edge of the rack-mount rails, are 19 inches wide. --Nineworlds 12:24, 16 January 2006 (UTC)
[edit] metric conversions
The metric quantities in the article should be *exact* conversions from the inches. These are specifications, not measurements, so do not round them off. Exact conversion: 1 inch == 25.4 mm. 195.224.75.71 14:18, 7 October 2005 (UTC)
This is very important when buying a rack. Remember in height a unit= 1.75 inches what ever that converts to; Good job, since I'm lost on metric stuff Scott 14:40, 7 October 2005 (UTC)
[edit] SC48D = IEC Subcommite
According to this pdf: http://www.ibsp.pl/oferta/eng/ds13_321.pdf, SC48D is an IEC Subcommitie?
[edit] Better pictures please
I don't see how this article could possibly need three different pictures of "generic rack setups", and still not have any good illustrations of the actual physical dimensions. There's a lot of numbers in there to keep track of, and some visual aid couldn't hurt. Even a closeup of two or three rack-mounted servers (or any equipment) would be useful.
(It'd be different if the pictures illustrated different types of equipment well, like "telephone switching equipment, circa 1962"; "a modern server room - 2U servers on the left, ethernet switches, etc, on the right"; "musical equipment - sound modules and audio effects processors". Now it all seems more like "old stuff in a rack"; "server stuff in a rack"; "stuff in a rack at location X" -- there doesn't seem to be any thought to it, just whatever was available at the moment. And yes, the bland descriptions contribute to that feeling.)
I'd suggest keeping the first (black and white) picture, with its generic description, and getting rid of the other two. It fits the mental image best, somehow.
-- magetoo 12:38, 4 December 2005 (UTC)
[edit] Bolt Sizes
"Originally the mounting holes were tapped to receive a particular type of threaded bolt. Racks with plain square holes are now common. Square-holed racks allow boltless mounting, and can be adapted for use with bolts by the use of cage nuts. A cage nut consists of a spring steel cage, designed to clip onto a square mounting hole, within which is a captive nut."
Although the statement above is correct, many of the common 19" racks still sold are tapped to utilize three standard bolt sizes. It may be wise to include the three standard bolt sizes (12-24, 10-32, & M6-Metric) as they are still pertinent in the industry.
- Go for it! Be Bold! -- RevRagnarok 12:03, 23 May 2006 (UTC)
[edit] Rack rails
What's the difference between fixed rails and telco rails? Edward 16:47, 4 June 2006 (UTC)
[edit] RETNA
What is the 19" RETNA standard?
[edit] Two-hole rack unit?
Some racks don't have the middle hole in each RU drilled (results in two close holes, then a big gap, two close holes, etc etc). Is this a different/older standard or the manufacturer being lazy?
58.106.147.222 21:51, 30 October 2006 (UTC)
[edit] history
Does anyone know where the unit of 19" for telecommunications equipment comes from ? I am curious why this size and not 20 or 18 inch ???