Forwarding for Gary... Jim ____________________Forward Header_____________________ Subject: RE: NEC Coax Protection Requirements Author: "VICTORINE;GARY (HP-Cupertino;ex1)" <[email protected]> List-Post: [email protected] Date: 09/17/99 9:47 PM
Hello, I don't think I can directly answer the original question. However, I can point out that Art. 830 has provisions for much greater power than allowed in Art. 820. Art. 830 also deals with the telecommunications network, which Art. 820 does not. These are significant factors that could account for the difference in the requirements you note. I would also like to comment on who really writes the NEC, at least in the context of Art. 830. Actually, Art. 830 is a new addition to the 1999 edition of the NEC. The article was primarily written by the Telecommunications industry. However, they did get much feedback from NFPA Code Panel 16 as well as other industry groups. Art. 830 addressed the need to add provisions in the NEC for new technology that integrated broadband communications, including telecommunications service, as well as power for the NIU (network interface unit) in the same cable. Art. 800, which also deals with telecommunications, didn't have provisions for the necessary power, etc., needed for this new technology. Much of the wording of Art. 830 was cloned from Art. 800, if you ignore the power considerations. I should also take this opportunity to note that work is already underway to develop the 2002 NEC. The National Fire Protection Association (NFPA) publishes the NEC with lots of help from industry contributors and volunteers. The deadline for submitting proposals is Nov. 5, 1999, less than two months from now. Submitting a proposal by the deadline is the primary way of making a change to the NEC, unless you're involved with one of the NEC Code Panels. One can make a proposal to change a single word or add a whole new Article. If something has been bugging you about the wording of some section in the NEC, you can take this opportunity to try and fix it. (You can also make a proposal to allow or permit you to do something where there currently are no provisions in the NEC, as in the Art. 830 example above). Otherwise, the next opportunity is three years from now for the 2005 NEC. ANY individual, company, or organization can submit a proposal. The entire change process involves a number of steps that I won't go into here, but the process starts with making a proposal. Check out the NFPA website for more details and for the proposal forms at http://www.nfpa.org/ (No, I don't get a commission for this). :>) Regards, Gary Victorine Hewlett-Packard Co. 408-447-3362 -----Original Message----- From: [email protected] [mailto:[email protected]] Sent: Friday, September 17, 1999 8:44 AM To: [email protected] Cc: [email protected] Subject: Re: NEC Coax Protection Requirements Never assume anything about the NEC. It is written by electricians for electricians and is plainly written for a national standard. Sec. 830-30 is written so it can apply to both twisted pair and coaxial cabling, underground and aerial mounting. The primary concern is lightning and power cross and grounding the shield in an acceptable way satisfies both criteria. Twisted pair without a shield requires primary protection in the NIU. Always read the NEC slowly so that all the implications sink in. It takes a while to adjust to the style. I am no expert on the NEC. I can refer you to another post for more info. [email protected] on 09/16/99 01:06:05 PM Please respond to [email protected] To: [email protected] cc: (bcc: Ed Rauch/RFP/RELTECCORP) Subject: NEC Coax Protection Requirements Greetings! Can anyone comment on the rationale for the difference in surge protection requirements between Article 820-33 (Community Antenna Television and Radio Distribution Systems) and Article 830-30 (Network-Powered Broadband Communications Systems)? In Article 820, it says that where the outer conductive shield of a coaxial cable is grounded, no other protective devices shall be required. But in article 830, which can also use coaxial cables, it says that primary electrical protection shall be provided on all network-powered broadband communications conductors that are not grounded. I'm assuming that this means overvoltage surge protection and that they are talking about the center conductor(s) of shielded coax. Thanks for any comments or direction toward additional, background information. Don Turner Siecor 847-699-2910 [email protected] --------- This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to [email protected] with the single line: "unsubscribe emc-pstc" (without the quotes). For help, send mail to [email protected], [email protected], [email protected], or [email protected] (the list administrators). --------- This message is coming from the emc-pstc discussion list. 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Received: from ruebert.ieee.org ([199.172.136.3]) by mail.monarch.com with SMTP (IMA Internet Exchange 3.12) id 0006066A; Fri, 17 Sep 1999 23:51:25 -0400 Received: by ruebert.ieee.org (8.8.8+Sun/8.8.8) id XAA22581 Received: from gemini.ieee.org by ruebert.ieee.org (8.8.8+Sun/8.8.8) with ESMTP id XAA22519; Fri, 17 Sep 1999 23:48:43 -0400 (EDT) Received: from palrel3.hp.com (palrel3.hp.com [156.153.255.226]) by gemini.ieee.org (8.9.3/8.9.3) with ESMTP id XAA04013 for <[email protected]>; Fri, 17 Sep 1999 23:47:24 -0400 (EDT) Received: from xboibrg2.boi.hp.com (xboibrg2.boi.hp.com [15.56.8.172]) by palrel3.hp.com (8.8.6 (PHNE_17135)/8.8.5tis) with ESMTP id UAA16247 for <[email protected]>; Fri, 17 Sep 1999 20:47:22 -0700 (PDT) Received: by xboibrg2.boi.hp.com with Internet Mail Service (5.5.2448.0) id <S80H7LWF>; Fri, 17 Sep 1999 21:47:21 -0600 Message-ID: <[email protected]> From: "VICTORINE,GARY (HP-Cupertino,ex1)" <[email protected]> To: "'[email protected]'" <[email protected]>, [email protected] Cc: [email protected], "VICTORINE,GARY (HP-Cupertino,ex1)" <[email protected]> Subject: RE: NEC Coax Protection Requirements List-Post: [email protected] Date: Fri, 17 Sep 1999 21:47:20 -0600 MIME-Version: 1.0 X-Mailer: Internet Mail Service (5.5.2448.0) Content-Type: text/plain; X-Resent-To: [email protected] Precedence: bulk --------- This message is coming from the emc-pstc discussion list. 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