Take a look at Article 725 of the National Electrical Code (NEC) for requirements in the United States. If the circuit is a power limited circuit, the NEC will not require a safety ground. See NEC Tables 11(A) and 11(B) for the definition of these circuits. You will find the requirements to be basically the same as the IEC 60950-1 requirements for Limited Power Sources.
For Europe, consider starting with IEC 60364. Many of the European electrical codes will have deviations from this standard, but the basic content should be similar. IEC 60364-4-411 allows SELV circuits to be ungrounded. Disclaimers: You will need to look at the power levels, isolation and circuit classifications of the signal in the cable. Information I have provided is for reference only; obtain copies of the standards and review them to make your own decision about the applicability of any clauses. Regards Ted Eckert Compliance Engineer Microsoft Corporation [email protected] The opinions expressed are my own and do not necessarily reflect those of my employer. From: Grasso, Charles [mailto:[email protected]] Sent: Tuesday, April 07, 2009 9:33 AM To: [email protected] Subject: Re: Security Camere Coax Grounding Neven – There *may* be building code requirements that you will have to meet. Not sure what those are. I suggest a review of the NEC2008. Chas ________________________________ From: [email protected] [mailto:[email protected]] On Behalf Of [email protected] Sent: Tuesday, March 24, 2009 3:32 PM To: [email protected] Subject: Security Camere Coax Grounding Can anyone help me understand what would be the requirement, preferably worldwide worst-case if possible, for connecting the outer conductor ("shield") of the coaxial cable (RG59) in a security-camera application? The cable can be up to 2000 ft (~ 600m) long, between the central unit (inside the building) and the remote camera (anywhere within the reach). The application can be anything from industrial to apartment buildings. Can I (or do I have to) connect the outer conductor to the safety ground (enclosure) on both ends? .. on one end (which?), etc. Alternatively, do I need to provide safety isolation from the outer conductor to the safety GND (enclosure?), how much, on which end, what kind of caps to GND can I use for EMI if I need safety isolation, etc.? I am asking strictly from the safety/regulatory hard requirement point of view, not trying to discuss which would be better for EMC. Is there an simple answer? Did I miss any key info or question? Thanks, Neven - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <[email protected]> All emc-pstc postings are archived and searchable on the web at http://www.ieeecommunities.org/emc-pstc Graphics (in well-used formats), large files, etc. can be posted to that URL. Website: http://www.ieee-pses.org/ 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]> - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <[email protected]> All emc-pstc postings are archived and searchable on the web at http://www.ieeecommunities.org/emc-pstc Graphics (in well-used formats), large files, etc. can be posted to that URL. Website: http://www.ieee-pses.org/ 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]> - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <[email protected]> All emc-pstc postings are archived and searchable on the web at http://www.ieeecommunities.org/emc-pstc Graphics (in well-used formats), large files, etc. can be posted to that URL. Website: http://www.ieee-pses.org/ 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]>
