RE>>IEC 950 / UL 1950 creepa 5/9/97
Me again........... Once you have determined which pollution degreee your product falls under, you can determine your creepage & clearance distances (in Table 6) by the CTI of your traces. (This is, to my understanding, of what "Material group" is) CTI ratings refers to the value obtained in accordance with method A of IEC 112. (Note: If you can't determine which material group you fall into, material group IIIb SHALL be assumed.) Regards, Regan -------------------------------------- List-Post: [email protected] Date: 5/9/97 12:42 PM To: Regan Arndt From: [email protected] RE>IEC 950 / UL 1950 creepage and* 5/9/97 The values for Pollution Degree 1 are applicable to components and assemblies which are sealed so as to exclude dust and moisture (see clause 2.9.6 of CSA C22.2 No. 950-95) The values for Pollution Degree 2 are generally applicable to equipment covered by the scope of the CSA C22.2 No. 950-95 standard (IEC 950 based) The values for Pollution Degree 3 are applicable where a local internal environment within the equipment is subject to conductive pollution or to dry-conductive pollution which could become conductive due to expected condensation. Regards, Regan Arndt Safety Technologist NORTEL -------------------------------------- List-Post: [email protected] Date: 5/9/97 12:27 AM To: Regan Arndt From: [email protected] To any and all safety gurus, I am in the midst of trying to minimize the creepage and clearance requirements between TNV and SELV called out in IEC 950. My interpretation of tables 5 and 6 in sections 2.9.2. and 2.9.3 are that minimum clearance is 2.0mm and minimum creepage is 2.5mm. This is based on a global design using up to 250V mains, pollution degree 1 & 2 and Material Group IIIa + IIIb. The application is for Class I as well as Class II systems. I could not find a reference explaining the definition of the Material Groups and would appreciate any insight into a clause, etc. which I could reference to reduce these spacing requirements. Please also advise if you are in need of further details. Thx, Joe ********************************************************************** Joe Finlayson Manager, Compliance Engineering Microcom, Inc. ------------------ RFC822 Header Follows ------------------ Received: by nmisq2.miss.nt.com with SMTP;9 May 1997 00:25:54 -0400 Received: from bcarsde4.localhost (actually bcarsde4.ott.bnr.ca) by bcarsfbb.ott.bnr.ca; Thu, 8 May 1997 15:10:47 -0400 Received: from europe.std.com by bcarsde4.localhost; Thu, 8 May 1997 15:04:59 -0400 Received: by europe.std.com (8.7.6/BZS-8-1.0) id PAA13113; Thu, 8 May 1997 15:08:45 -0400 (EDT) Received: from world.std.com by europe.std.com (8.7.6/BZS-8-1.0) id PAA13100; Thu, 8 May 1997 15:08:40 -0400 (EDT) Received: from sw.microcom.com by world.std.com (5.65c/Spike-2.0) id AA02571; Thu, 8 May 1997 15:08:40 -0400 Received: from sw.microcom.com (root@localhost) by sw.microcom.com (8.7.5/8.7.3) with ESMTP id PAA24783 for <[email protected]>; Thu, 8 May 1997 15:09:38 -0400 (EDT) Received: from smtp.microcom.com ([199.99.215.11]) by sw.microcom.com (8.7.5/8.7.3) with SMTP id PAA24770 for <[email protected]>; Thu, 8 May 1997 15:09:37 -0400 (EDT) Received: from ccMail by smtp.microcom.com (IMA Internet Exchange 2.1 Enterprise) id 00016C26; Thu, 8 May 97 15:11:58 -0400 Mime-Version: 1.0 List-Post: [email protected] Date: Thu, 8 May 1997 15:01:07 -0400 Message-Id: <[email protected]> From: [email protected] (Joe Finlayson) Subject: IEC 950 / UL 1950 creepage and clearance requirements To: [email protected] Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Content-Description: cc:Mail note part Sender: [email protected] Precedence: list Reply-To: [email protected] ------------------ RFC822 Header Follows ------------------ Received: by nmisq2.miss.nt.com with SMTP;9 May 1997 12:37:00 -0400 Received: from bcarsde4.localhost (actually bcarsde4.ott.bnr.ca) by bcarsfbb.ott.bnr.ca; Fri, 9 May 1997 10:10:05 -0400 Received: from europe.std.com by bcarsde4.localhost; Fri, 9 May 1997 10:01:27 -0400 Received: by europe.std.com (8.7.6/BZS-8-1.0) id KAA24496; Fri, 9 May 1997 10:04:59 -0400 (EDT) Received: from world.std.com by europe.std.com (8.7.6/BZS-8-1.0) id KAA24488; Fri, 9 May 1997 10:04:56 -0400 (EDT) Received: from bcarsde4.localhost (mailgate.nortel.ca) by world.std.com (5.65c/Spike-2.0) id AA01362; Fri, 9 May 1997 10:04:50 -0400 Received: from bcars735.ott.bnr.ca (actually 47.128.2.191) by bcarsde4.localhost; Fri, 9 May 1997 09:51:43 -0400 Received: from nmiss1.miss.nt.com by bcars735.ott.bnr.ca; Fri, 9 May 1997 09:55:32 -0400 Message-Id: <[email protected]> List-Post: [email protected] Date: 9 May 1997 07:52:05 -0400 From: [email protected] Subject: Re: IEC 950 / UL 1950 creepa To: [email protected] X-Mailer: Mail*Link SMTP-QM 3.0.3.97.04.01 Sender: [email protected] Precedence: list Reply-To: [email protected] MIME-version: 1.0 Content-type: text/plain; charset="ISO-8859-1"; Name="Message Body" Content-transfer-encoding: quoted-printable
