Chris, The standard (UL1950/EN 60 950) allows you to conduct an Impulse Test in lieu of a Dielectric Strength Test. The MOVS should be left in place when doing an Impulse Test. Most probably you will pass using the Impulse Test Method and you do not need to spend money on re-work or perpheral devices. Your only problem is Australia which requires passing both a Dielectric Strength and Impulse Test, both at a slightly higher voltage than the EN 60 950/UL1950 standards.
Best Regards At 10:33 22/05/2000 -0400, Maxwell, Chris wrote: > >Group, > >Is there an in-line adapter that we can install on a TNV line (in our case, >a typical RJ12 phone line) to our product that will provide a second layer >of hi-pot protection? The whole explanation follows for those who think >they can help. Others can press delete right now and get on with their day. > >We produce a piece of fiber optic test equipment that is rack mounted and >operates from 48VDC. Most of our typical equipment does not have TNV >connections, however this does. We have designed a "remote reset" option. >The remote reset consists of an RJ12 jack on the back of the unit. The user >can plug a phone line into this jack. Once installed, the user can perform >a 5 second power down on the unit by dialing the unit's "phone number" and >letting the line ring 5 times. > >This has proved valuable to customers because the units are designed for >remote installation. If the unit hangs up, they don't have to drive, fly, >hike or swim out to where the unit is installed to perform a hard re-boot. > >This remote reset line only takes in the "TIP" and "RING" signals (the RJ12 >only has pins 3 and 4 populated). Both TIP and RING have MOV's going to >chassis ground. We have had the unit safety tested. During safety testing, >the MOV's were cut (creating a single fault condition). When the MOV's were >cut, the hipot test caused an arc to ground on a circuitboard within the >unit. This arc was considered a failure. My guess is that the arc is >caused by the fact that the tip and ring signals run close to a piece of the >ground plane on the top layer of the board. My first stab at fixing this >would be to clear out the ground plane so that it is furthur away from tip >and ring. > >Now, even minor changes to circuitboards can cost thousands. It can also >mean scrap. This unit is a very low volume product (hundreds annually). It >may be more cost effective for us to add some sort of in-line suppressor >external to the unit as opposed to revising the circuitboard. Given that >the unit is rack mounted, I am assuming that there would be room in the rack >to mount such a device, if it existed. Hence my question. > >Anybody have any ideas? > >Thank you for your time. > >Chris Maxwell, Design Engineer >GN Nettest Optical Division >109 N. Genesee St. >Utica, NY 13502 >PH: 315-797-4449 >FAX: 315-797-8024 >EMAIL: chr...@gnlp.com > > > >------------------------------------------- >This message is from the IEEE EMC Society Product Safety >Technical Committee emc-pstc discussion list. > >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: > Jim Bacher: jim_bac...@mail.monarch.com > Michael Garretson: pstc_ad...@garretson.org > >For policy questions, send mail to: > Richard Nute: ri...@ieee.org > > Peter Merguerian Managing Director Product Testing Division I.T.L. (Product Testing) Ltd. Hacharoshet 26, POB 211 Or Yehuda 60251, Israel Tel: 972-3-5339022 Fax: 972-3-5339019 e-mail: pmerguer...@itl.co.il website: http://www.itl.co.il ------------------------------------------- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson: pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
