RE>>Spacing 10/24/96
I disagree with the statement that the good ole U.S. doesn't care about the spacings. In CSA 22.2 No.225, they didn't, but with the bi-national standard, CSA 22.2 No. 950, UL 1950, they do care about the spacings regardless if you pass overvoltage. See section 6 of the standard. Almost every clause states that "There SHALL BE XXX insulation....." etc. Spacings are a form of insulation! It does not state anywhere in CSA 22.2 No. 950 that if you pass the OV test, you do not have to meet any spacings requirements. Regan Arndt Safety Technologist Nortel -------------------------------------- List-Post: [email protected] Date: 10/23/96 5:42 PM To: Regan Arndt From: [email protected] ----- E X T E R N A L L Y O R I G I N A T E D M E S S A G E ----- On 22 October, Ron Newton asked: > What is the minimum spacing in inches or millimeters for: (1) tip to > ring (2) tip/ring to ground (3) tip/ring to other conductors? > > Thanks, > Rob Newton > > [email protected] Oh, that it were so simple! Sorry, Ron, but the bureaucrats have bagged you again. Here are some questions YOU must answer first. 1) What country is this product for, and what specification applies? For example, the good ole USA does not care what your spacings are, as long as your product survives the UL 1489 or UL 1950 overvoltage tests. Most of the rest of the world uses EN60 950, which does specify spacings, but requires that you answer the following. 2) Is your product standalone, like a MUX or a PBX? If so, the highest voltages you have to worry about are the Telephone Network Voltages which are generally 150 vrms (48 vdc battery + 100 vrms ring voltage). However, if your product goes into a personal computer that might be powered from 240 vac mains, then you have to work with a 240-250 volt rating that requires wider separation. 3) Now we get into the fun stuff!! What is your pollution degree and your Material Group. You say you don't know? Welcome to the club. Most mortals dwell in the area of Pollution Degree 2 and Material Group III. Also, most of us do not depend on solder mask as an insulator, since solder mask can be scratched, peeled, or otherwise damaged. 4) We're getting closer, but now you must decide if you are required to use reinforced insulation. Most of us are not, as our power supplies use double or reinforced insulation. Now you can enter the inner sanctum of table 6 of EN60 950 and pick a creepage distance. For 150 v, Pollution Degree 2, Material Group III, you'll find 1.6mm. (If you must use 250 v per question 1above, the table says to use 2.5 mm.) If you are required to show reinforced insulation, then double these numbers. These numbers are the spacing required from tip and ring to ground, or to any other SELV voltage. (In English, a SELV voltage is less than 42.4 v pk and less than 60 vdc). I believe that tip-to-ring must be 0.3 mm, but I don't recall the basis of this number. If you have any other simple questions, let me know. Pete ---------------------------------------------------------------------------- Peter Van Raalte | Email: [email protected] Compliance Engineer | V-Band Corporation | Phone: 914-789-5117 565 Taxter Road | Elmsford NY 10523 | FAX: 914-347-3432 --------------------------------------------------------------------------- ------------------ RFC822 Header Follows ------------------ Received: by nmisq2.miss.nt.com with SMTP;23 Oct 1996 17:38:05 -0400 Received: from europe.std.com by corpgate.rich.nt.com with SMTP (PP); Wed, 23 Oct 1996 21:34:08 +0000 Received: by europe.std.com (8.7.5/BZS-8-1.0) id QAA15883; Tue, 22 Oct 1996 16:52:32 -0400 (EDT) X-Authentication-Warning: europe.std.com: daemon set sender to treg-approval using -f Received: from world.std.com by europe.std.com (8.7.5/BZS-8-1.0) id QAA15862; Tue, 22 Oct 1996 16:52:29 -0400 (EDT) Received: from uumx.smtp.psi.net by world.std.com (5.65c/Spike-2.0) id AA27222; Tue, 22 Oct 1996 16:46:05 -0400 Received: from uu3.psi.com by uumx.smtp.psi.net (8.6.12/SMI-4.1.3-PSI) id QAA14445; Tue, 22 Oct 1996 16:28:10 -0400 Received: from exec.vband.com by uu3.psi.com (5.65b/4.0.940727-PSI/PSINet) via SMTP; id AA27488 for [email protected]; Tue, 22 Oct 96 16:28:05 -0400 Received: from EXEC/SpoolDir by exec.vband.com (Mercury 1.21); 22 Oct 96 16:25:09 EDT Received: from SpoolDir by EXEC (Mercury 1.21); 22 Oct 96 16:24:57 EDT From: Pete Van Raalte <[email protected]> Organization: V Band Corporation To: [email protected] List-Post: [email protected] Date: Tue, 22 Oct 1996 16:24:52 EST Subject: Re: Spacing Priority: normal X-Mailer: Pegasus Mail/Windows (v1.22) Message-Id: <[email protected]> Sender: [email protected] Precedence: bulk Reply-To: [email protected]
