From: Constantin Bolintineanu <[email protected]> Subject: RE: UL1950 Overvoltage Tests
Hi Peter, I have the same filling that the Protection against OV from power line crosses is a sensitive issue as it is described within the Clause 6.6 UL1950/CAN CSA C22.2 No.950,( "Protection against overvoltage from power line crosses.") Compliance with the applicable requirements is checked both, by inspection (construction requirements) and test conditions(Annex NAC). Assuming that the Construction requirements are OK, see as well conditions applicable to figure 18d,(e.g. Condition Nr.5 : " In addition to the requirements for a FIRE ENCLOSURE , both of the following requirements apply...a) and b) [ Fig.18b was revised March 1, 1998], thus NAC.4 Compliance is applicable. I am not convinced that I understood were was the "slight charring" , only on the PCB OR of the cheesecloth indicator... After the completion of the tests "the EUT shall comply with either DVW[ Dielectric Voltage Withstand] with all the components in place, or the LC [Leakage current]...", here I have another question for you, did you have all the components in place after the OV tests ? If the EUT evaluated did not show charring of the cheesecloth indicator AND during the DVW test all the components were in place ,and passed the test AND the equipment meet the Construction requirements, I will say that the equipment complies with the requirements of the Clause 6.6 Respectfully yours, Constantin Bolintineanu P.Eng. Product Safety Engineer DIGITAL SECURITY CONTROLS LTD. [email protected] The opinions expressed are my own and not necessarily those of my employer. > -----Original Message----- > From: [email protected] [SMTP:[email protected]] > Sent: Monday, January 04, 1999 4:37 PM > To: [email protected] > Cc: '[email protected]' > Subject: UL1950 Overvoltage Tests > > > Happy New Year to All, > > I would like to ask the opinion of all members regarding compliance > criteria for the Overvoltage Tests in on TNV lines connected to > exposed plant. UL1950 states that after the OV Tests, unit must > comply with the Dielectric Voltage Withstand Tests or Leakage > Current Tests. > > Assuming that after the OV Tests, some internal traces of the > board opened and caused slight charring on the PCB and the unit > passed all applicable Dielectric Voltage Withstand Tests, would > this be cosnidered an acceptable result? > > Looking forward to hearing from all members on this sensitive issue. > > > > PETER S. MERGUERIAN > MANAGING DIRECTOR > PRODUCT TESTING DIVISION > I.T.L. (PRODUCT TESTING) LTD. > HACHAROSHET 26, P.O.B. 211 > OR YEHUDA 60251, ISRAEL > > TEL: 972-3-5339022 > FAX: 972-3-5339019 > E-MAIL: [email protected] > Visit our Website: http://www.itl.co.il > > --------- > 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).
