Forwarded message: From: Self <Single-user mode> To: [email protected] Subject: UL1950/CSA C22.2 950 Third Edition; Telco Overvoltage Tests List-Post: [email protected] Date: Fri, 9 Oct 1998 23:50:09 +0200
Dear Fellow members, After the application of the Overvoltage Tests to telecom interfaces subjected to exposed plant, one of criteria for passing to the above specified standards is the application of a Dielectric Voltage Withstand Test or the Leakage Current Test. As such, if the manufacturer failed the Dielectric Voltage Withstand Test, manufacturer can choose to comply with the Leakage Current Test. As the standard is written today, it is not necessary to apply a 600 V to the telephone interface (to simulate a power line coming across the telephone interface) when conducting the Leakage Current Test. Application of the 600 V to the telephone interface when measuring Leakage per the Standards for Telephone Equipment UL1459 and CSA C22.2 225 was a common practice and makes sense. I believe there was a big mistake in overlooking this point when the UL1950/CSA C22.2 950 standard was developed. I know one manufacturer with a piece of equipment which was submitted to one NRTL and received Listing (because after failing Dielectric Strength Test, they passed the Leakage Current Test- obviously he passed since 600 V was not applied to the telco interface). When OEM submitted the same piece of equipment to another NRTL, they couldn't get Listing since engineer evaluating product applied 600 V to the telco interface when measuring Leakage (even though standard does not require it) and the product failed the test. Any comments, especially from pstc members who are also in the North American Standardization Committe for UL1950/CSA C22.2 950? --------- 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).
