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 [email protected] ED&D www.productsafeT.com -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of [email protected] Sent: Friday, October 25, 2002 10:24 AM To: [email protected] 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: [email protected] with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: [email protected] Dave Heald: [email protected] For policy questions, send mail to: Richard Nute: [email protected] Jim Bacher: [email protected] 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: [email protected] with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: [email protected] Dave Heald: [email protected] For policy questions, send mail to: Richard Nute: [email protected] Jim Bacher: [email protected] 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"
