RE: Layered Reinforced Insulation
Richard, From UL's database, the CL3P cable is a Power Limited Cable - Indicates cable intended for use in Class 2 or Class 3 circuits within buildings in ducts or plenums or other spaces used for environmental air in accordance with Section 725.61(A) of the NEC. This cable exhibits a maximum peak optical density of 0.5 a maximum average optical density of 0.15, and a maximum flame spread distance of 5 ft, when tested per NFPA 262, Standard Method of Test for Flame Travel and Smoke of Wires and Cables for Use in Air-Handling Spaces. If the use of this cable is for Class 2 and Class 3 circuits, then per the NEC maximum allowed voltage is 150 V. Assuming your circuit was Limited Current (see 2.4 of 60950), there is no need for the reinforced insulation requirements since the hazardous circuit becomes a Limited Current Circuit. All the Best, This e-mail message may contain privileged or confidential information. If you are not the intended recipient, you may not disclose, use, disseminate, distribute, copy or rely upon this message or attachment in any way. If you received this e-mail message in error, please return by forwarding the message and its attachments to the sender. PETER S. MERGUERIAN Technical Director I.T.L. (Product Testing) Ltd. 26 Hacharoshet St., POB 211 Or Yehuda 60251, Israel Tel: + 972-(0)3-5339022 Fax: + 972-(0)3-5339019 Mobile: + 972-(0)54-838175 http://www.itl.co.il http://www.i-spec.com -Original Message- From: richwo...@tycoint.com [mailto:richwo...@tycoint.com] Sent: Monday, October 28, 2002 7:48 PM To: emc-p...@majordomo.ieee.org Subject: RE: Layered Reinforced Insulation OK, I'll get more specific. I have an external interconnecting cable that contains hazardous voltages. Because of the application, in the USA I must use UL Listed CL3P cable which is rated for use in risers and air handling spaces (smoke requirements of the National Electrical Code). The insulation system of a standard CL3P cable consists of the wire insulation and external jacket, and the sum thickness is 0.4 mm. It is not clear that the insulation parts are constructed of the same material. I must determine if the cable complies with the reinforced insulation requirements of UL60950/EN60950, or if I need to have a special cable constructed. Someone mentioned that the two insulations must be the same material in order for the system to be classified as reinforced. I cannot find that requirement in the standard. Nor can I find any statement that says that a two part insulation system must consider one part to be basic insulation and the other part to be supplementary insulation. Frankly, I can find nothing in the standard that indicates why the particular construction of this cable is not allowed to be considered as reinforced insulation. The only issue at hand, it appears, is that it must be shown that the insulation is mechanically durable in the intended application. That is where I rely upon the the UL Listing - they seem to believe that it is perfectly acceptable for a 300V interconnection application - at least the kind that my equipment will employ. Your comments would be appreciated. Richard Woods Sensormatic Electronics Tyco International --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list
RE: Layered Reinforced Insulation
I too have had some struggles with this concept. I now tend to think of Basic, Reinforced and Double more in terms of an insulation strength as opposed to an actual material. For instance, Double insulation can be provided by a properly set and maintained distance through air, i.e no material at all. You could also call this a Reinforced insulation, since it is made up of one layer of air reinforced by more air. Of course, there are certain rules that the standards apply if you do use an actual insulator to provide Basic, Reinforced and/or Double insulation. These rules mostly dictate that: a. The insulation be strong enough to provide the required insulation strength. b. The insulation can withstand the temperatures to be expected in the product. c. The insulation is thick enough or constructed with enough layers to prevent an accidental breach from either a pinhole or a void. d. The insulation won't change its properties in the presence of humidity. (No plywood insulation!!! :-) ) e. The insulation won't wear off, crack, peel or abrade under reasonably foreseeable circumstances. What I'm saying is...call the insulation whatever you want. Just make sure that it works. Chris Maxwell | Design Engineer - Optical Division email chris.maxw...@nettest.com | dir +1 315 266 5128 | fax +1 315 797 8024 NetTest | 6 Rhoads Drive, Utica, NY 13502 | USA web www.nettest.com | tel +1 315 797 4449 | Chris Maxwell | Design Engineer - Optical Division email chris.maxw...@nettest.com | dir +1 315 266 5128 | fax +1 315 797 8024 NetTest | 6 Rhoads Drive, Utica, NY 13502 | USA web www.nettest.com | tel +1 315 797 4449 | --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list
Re: Layered Reinforced Insulation
I read in !emc-pstc that richwo...@tycoint.com wrote (in 846BF526A205F8 4BA2B6045BBF7E9A6A046758DF@flbocexu05) about 'Layered Reinforced Insulation' on Mon, 28 Oct 2002: Someone mentioned that the two insulations must be the same material in order for the system to be classified as reinforced. I cannot find that requirement in the standard. Nor can I find any statement that says that a two part insulation system must consider one part to be basic insulation and the other part to be supplementary insulation. These requirements may have been in *an* edition of the standard, but it has changed a lot over the years. You need to look at the latest edition, IEC 60950-1. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list
RE: Layered Reinforced Insulation
OK, I'll get more specific. I have an external interconnecting cable that contains hazardous voltages. Because of the application, in the USA I must use UL Listed CL3P cable which is rated for use in risers and air handling spaces (smoke requirements of the National Electrical Code). The insulation system of a standard CL3P cable consists of the wire insulation and external jacket, and the sum thickness is 0.4 mm. It is not clear that the insulation parts are constructed of the same material. I must determine if the cable complies with the reinforced insulation requirements of UL60950/EN60950, or if I need to have a special cable constructed. Someone mentioned that the two insulations must be the same material in order for the system to be classified as reinforced. I cannot find that requirement in the standard. Nor can I find any statement that says that a two part insulation system must consider one part to be basic insulation and the other part to be supplementary insulation. Frankly, I can find nothing in the standard that indicates why the particular construction of this cable is not allowed to be considered as reinforced insulation. The only issue at hand, it appears, is that it must be shown that the insulation is mechanically durable in the intended application. That is where I rely upon the the UL Listing - they seem to believe that it is perfectly acceptable for a 300V interconnection application - at least the kind that my equipment will employ. Your comments would be appreciated. Richard Woods Sensormatic Electronics Tyco International --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list
RE: Layered Reinforced Insulation
I certainly agree that reinforced can be a solid insulation - hence the 0.4. mm thickness requirement. Sorry if my memo gave you a different impression. Bill Bisenius bi...@productsafet.com -Original Message- From: owner-emc-p...@majordomo.ieee.org [mailto:owner-emc-p...@majordomo.ieee.org] On Behalf Of Peter L. Tarver Sent: Friday, October 25, 2002 4:41 PM To: emc-p...@majordomo.ieee.org Subject:RE: Layered Reinforced Insulation Bill - This is not quite correct. Reinforced Insulation may also be a single piece of insulation (I do note you used may). There's no definition, per se, of multiple layers, except for the case of thin sheet material. Regards, Peter L. Tarver, PE Product Safety Manager Sanmina-SCI Homologation Services San Jose, CA peter.tar...@sanmina-sci.com From: Bill Bisenius A reinforced insulation system by definition may be multiple layers if it is all the same insulating material. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list
RE: Layered Reinforced Insulation
Richard - Which edition are you referring to? 2.2.1 in EN60950-1 and EN60950, 3rd ed., addresses general requirements for SELV circuits. In these standards, there is also no 2.9.4.anything. I'll assume for now that it's 2nd ed., through the 4th amendment. 2.9.4.2 refers to thin sheet material and accepting thin sheet material as a valid construction method for Reinforced Insulation, it must be physically protected; hence internal to a mechanical enclosure. This was written into the standard to allow common transformer constructions to meet Reinforced insulation requirements and other 2.9.4.1 states Reinforced Insulation can be 0.4 mm, and is not precluded from being outside the enclosure, *if* it's not subject to mechanical stresses that can deform the insulation at normal operating temperatures (it implies it *can* deform under abnormal operating conditions that lead to abnormal temperatures). [Be sure to pay attention to the Note.] What you've described seems more like a combination of Basic Insulation (the inner, single conductor insulation) and Supplementary Insulation (the jacket). If the cable is outside the enclosure, it should be jacketed for mechanical protection. Jacketed cables offer many thicknesses of jacket such that you could readily find one that has a 0.4 mm thickness (16 mils). Regards, Peter L. Tarver, PE Product Safety Manager Sanmina-SCI Homologation Services San Jose, CA peter.tar...@sanmina-sci.com From: richwo...@tycoint.com Consider the insulation construction for an external interconecting cable connected to secondary hazardous circuits of ITE (EN60950). Is it permissible for the reinforced insulation to be constructed of two layers (e.g., conductor insulation plus external jacket) if the total thickness is at least 0.4 mm? Clause 2.2.1 appears to allow it; however, clause 2.9.4.2 appears to indicate that layered insulation can only be used internally. Richard Woods Sensormatic Electronics Tyco International --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list
RE: Layered Reinforced Insulation
Bill - This is not quite correct. Reinforced Insulation may also be a single piece of insulation (I do note you used may). There's no definition, per se, of multiple layers, except for the case of thin sheet material. Regards, Peter L. Tarver, PE Product Safety Manager Sanmina-SCI Homologation Services San Jose, CA peter.tar...@sanmina-sci.com From: Bill Bisenius A reinforced insulation system by definition may be multiple layers if it is all the same insulating material. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list
RE: Layered Reinforced Insulation
A reinforced insulation system by definition may be multiple layers if it is all the same insulating material. Two different insulating materials must be evaluated as double insulation = one of the materials must meet the requirements for basic insulation, the other material must meet the requirements for supplementary insulation. Regardless, both supplementary and reinforced insulation are required to be min. 0.4 mm thick (clause 2.10.5.1) There is an exception to the 0.4 mm thickness requirement if multiple layers - of the same insulating material (clause 2.10.5.2). The exception has additional dielectric testing requirements that depend on the number of layers used. You don't provide any details on the hazardous circuit in the interconnecting cable. If it can be defined as ELV, you will only need to evaluate one of the insulating materials as supplementary insulation. Still doesn't get you past the 0.4 mm requirement. Note - I have found many wire insulations that will meet the 0.4 mm requirement and comply with the reinforced insulation requirements. Best regards, Bill Bisenius bi...@productsafet.com EDD www.productsafeT.com -Original Message- From: owner-emc-p...@majordomo.ieee.org [mailto:owner-emc-p...@majordomo.ieee.org] On Behalf Of richwo...@tycoint.com Sent: Friday, October 25, 2002 10:24 AM To: emc-p...@majordomo.ieee.org Subject:Layered Reinforced Insulation Consider the insulation construction for an external interconecting cable connected to secondary hazardous circuits of ITE (EN60950). Is it permissible for the reinforced insulation to be constructed of two layers (e.g., conductor insulation plus external jacket) if the total thickness is at least 0.4 mm? Clause 2.2.1 appears to allow it; however, clause 2.9.4.2 appears to indicate that layered insulation can only be used internally. Richard Woods Sensormatic Electronics Tyco International --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list
