Re: Network Equipment and UL 1459/1950
Posting for a non list member.. >>> "Victor L. Boersma" 03/29 5:54 PM >>> Message text written by INTERNET:t...@world.std.com >I have to agree that there shouldn't be another US (UL) standard for network equipment when the equipment can be incorporated into UL1950. UL1950 can be revised to clarify the network equipment requirements, perhaps as a "deviation" or an "appendix" (annex), or just rewording the existing sections to make it easier to follow.< The reason why we went the UL1950 route was to be able to join the IECEE Schemes, where it is a prerequisite that the nation use the governing IEC Publication with a minimum of deviations. We had a bit if a difficult time with the IEC and are supposed to show how we are "DECREASING" the number of deviations, not increasing them. We had a difficult time to convince the data processing industry to embrace customer premises equipment. We never could get an international agreement to incorporate Central Office equipment. I may be mistaken, but I do not believe that we will get support from the main stakeholders in UL1950, to increase the number of deviations to accomodate Central Office equipment. Therefore, incorporating such requirements in a UL1459/CSA 225 product makes most sense. Even if we could get support in North America to propose modifications to IEC 60950 to accomodate CO equipment, we are talking about a process that will take years. I am afraid I start sounding like all the other would-be historians in making these comments and my white hair and arthritic knees don't help the image. Nevertheless, a bit of history helps in understanding some of these things. Regards, Vic Boersma - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: "unsubscribe emc-pstc" (without the quotes). For help, send mail to ed.pr...@cubic.com, j...@gwmail.monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
Re: Network Equipment and UL 1459/1950
Message text written by INTERNET:t...@world.std.com >I have to agree that there shouldn't be another US (UL) standard for network equipment when the equipment can be incorporated into UL1950. UL1950 can be revised to clarify the network equipment requirements, perhaps as a "deviation" or an "appendix" (annex), or just rewording the existing sections to make it easier to follow.< The reason why we went the UL1950 route was to be able to join the IECEE Schemes, where it is a prerequisite that the nation use the governing IEC Publication with a minimum of deviations. We had a bit if a difficult time with the IEC and are supposed to show how we are "DECREASING" the number of deviations, not increasing them. We had a difficult time to convince the data processing industry to embrace customer premises equipment. We never could get an international agreement to incorporate Central Office equipment. I may be mistaken, but I do not believe that we will get support from the main stakeholders in UL1950, to increase the number of deviations to accomodate Central Office equipment. Therefore, incorporating such requirements in a UL1459/CSA 225 product makes most sense. Even if we could get support in North America to propose modifications to IEC 60950 to accomodate CO equipment, we are talking about a process that will take years. I am afraid I start sounding like all the other would-be historians in making these comments and my white hair and arthritic knees don't help the image. Nevertheless, a bit of history helps in understanding some of these things. Regards, Vic Boersma
Re: Network Equipment and UL 1459/1950
Hello All, I have to agree that there shouldn't be another US (UL) standard for network equipment when the equipment can be incorporated into UL1950. UL1950 can be revised to clarify the network equipment requirements, perhaps as a "deviation" or an "appendix" (annex), or just rewording the existing sections to make it easier to follow. I think the network equipment has proven its safety over time, and UL, by having a UL1459 standard implies they agree, along with Telcordia (Bellcore) (GR-1089). It shouldn't be much of an issue to clarify UL1950 to include network equipment constructions. Reviving UL1459 only opens the door to confusion, making it more difficult to achieve a "worldwide" certified piece of equipment. We want to move towards harmonization worldwide, we don't want to increase the gap. I'm also afraid we would wind up adding "UL1459 Listed" to our long list of certifications on the back of the equipment! I hope this helps. Regards, Bob Tims Compliance Engineer Ericsson Messaging Systems Inc. Peter Merguerian wrote: > Jim, > > Your interpretaion is 100% correct. I have personally Listed many > products with UL1950 Third Edition with a supplemental earthing > terminal as you described below with no basic insulation between > the TNV-2/TNV-3 circuits and SELV/Earth. > > The standard specifies that basic insulation is one way of > complying with the requirements. Another way is as you describe > in your e-mail and which I have used to Approve lots of equipment > worldwide. However, the standard goes on to say "other solutions > are not excluded". > > My question to you all does anyone have a design or could give > some examples using "other solutions are not excluded"? > > PS - The IEC 950 WG7 Committe (Telecoms) is currently working > on Remote Power Feeding Requirements. Some members of the > committe are also from the US and Canada. We are working > together to come up with solutions. A lot of work still remains and I > am hopeful that within 2 years we should have common > requirements (of course as usual, with deviations for member > countries). I strongly feel that there is really no need to come up > with a new standard for network equipment since the UL1950 will > eventually have the remote power feed requirements included. > > Best Regards, > > > In a message dated 3/24/99, jim.wi...@adtran.com writes: > > > > > The only design criteria with regard to insulation in Bellcore standards > > > or > > UL 1459 is a hi-pots test. > > > Creepage and clearance do not exist in traditional C.O. equipment (just > > > look > > at wire wrapped > > > backplanes). > > > > > > Dear Jim and others: > > > > Jim Wiese has raised several concerns regarding the transition from UL 1459 > > to > > UL 1950 (3rd Edition). One of these concerns relates to the new creepage > > and > > clearance requirements for separation of TNV circuits and ground/SELV. > > > > I would like to pick up on this one issue (I know that Jim has raised > > several > > other issues as well). In particular, I would like some feedback from > > others > > in the group regarding my interpretation of how the separation requirements > > in > > UL 1950 apply to certain types of equipment. > > > > Just this week I met with a PBX manufacturer who is in the process of re- > > designing the backplane and all of the line cards in their PBX to "comply > > with > > UL 1950." The PBX is presently approved to UL 1459, but the manufacturer > > has > > its eye on the March 2000 date for new or modified products to comply with > > UL > > 1950. Needless to say, the redesign effort is an expensive one. > > > > The biggest headache in the redesign is complying with the creepage and > > clearance distances for separation of TNV and SELV circuits. The PBX > > manufacturer seemed incredulous when I stated that I did not think the > > creepage and clearance requirements applied to their product, since the PBX > > has a permanent (hardwired) connection to ground. My interpretation is > > based > > primarily on the following statement in clause 6.2.1.2 in UL 1950, > > paraphrased > > below: > > > > " Basic insulation is not required provided that all of the following > > conditions are met: > >- the SELV circuit is connected to protective earth...in accordance > > with 2.5; and > >- the installation instructions specifya permanent connection to > > earth; > > and > >- the test of 6.2.1.3 is carried out... (where applicable)" > > > > There are other clauses that call out isolation, such as 6.3.3.1 and 6.4.1, > > but the "permanent ground" exemption appears to apply here as well. > > > > In my view, these exemptions are specifically targeted at equipment such as > > PBXs and network equipment that are typically installed by service personnel > > and include hardwired grounding. Without these exemptions, it is almost > > impossible to separate certain types of TNV circuits from SELV and ground. > > For example, a feed circu
RE: Network Equipment and UL 1459/1950
Yep, That is one way of doings things to make product compliant to UL1950. Octel Communications Corporation was doing this before we were even a gleam in Lucent's eye. Tania Grant, Lucent Technologies, Octel Messaging Division tgr...@lucent.com -- From: Jody Leber [SMTP:jle...@ustech-lab.com] Sent: Thursday, March 25, 1999 7:03 AM To: 'emc-p...@majordomo.ieee.org' Subject: RE: Network Equipment and UL 1459/1950 We just completed an approval with the exact same situation. I cannot speak for your prodcut since I have not reviewed it. I can provide a contact at UL if required. One of the big concerns is the R/C connectors normally used for bringing the lines in do not even meet UL1950 unless pins are skipped. Best Regards, Jody Leber jle...@ustech-lab.com http://www.ustech-lab.com U. S. Technologies 3505 Francis Circle Alpharetta, GA 30004 770.740.0717 Fax: 770.740.1508 -Original Message- From: j...@aol.com [SMTP:j...@aol.com] Sent: Wednesday, March 24, 1999 3:42 PM To: emc-pstc; 'TREG' Cc: jim.wi...@adtran.com Subject: Re: Network Equipment and UL 1459/1950 In a message dated 3/24/99, jim.wi...@adtran.com writes: > The only design criteria with regard to insulation in Bellcore standards or UL 1459 is a hi-pots test. > Creepage and clearance do not exist in traditional C.O. equipment (just look at wire wrapped > backplanes). Dear Jim and others: Jim Wiese has raised several concerns regarding the transition from UL 1459 to UL 1950 (3rd Edition). One of these concerns relates to the new creepage and clearance requirements for separation of TNV circuits and ground/SELV. I would like to pick up on this one issue (I know that Jim has raised several other issues as well). In particular, I would like some feedback from others in the group regarding my interpretation of how the separation requirements in UL 1950 apply to certain types of equipment. Just this week I met with a PBX manufacturer who is in the process of re- designing the backplane and all of the line cards in their PBX to "comply with UL 1950." The PBX is presently approved to UL 1459, but the manufacturer has its eye on the March 2000 date for new or modified products to comply with UL 1950. Needless to say, the redesign effort is an expensive one. The biggest headache in the redesign is complying with the creepage and clearance distances for separation of TNV and SELV circuits. The PBX manufacturer seemed incredulous when I stated that I did not think the creepage and clearance requirements applied to their product, since the PBX has a permanent (hardwired) connection to ground. My interpretation is based primarily on the following statement in clause 6.2.1.2 in UL 1950, paraphrased below: " Basic insulation is not required provided that all of the following conditions are met: - the SELV circuit is connected to protective earth...in accordance with 2.5; and - the installation instructions specifya permanent connection to earth; and - the test of 6.2.1.3 is carried out... (where applicable)" There are other clauses that call out isolation, such as 6.3.3.1 and 6.4.1, but the "permanent ground" exemption appears to apply here as well. In my view, these exemptions are specifically targeted at equipment such as PBXs and network equipment that are typically installed by service personnel and include hardwired grounding. Without these exemptions, it is almost impossible to separate certain types of TNV circuits from SELV and ground. For example, a feed circuit that provides 48V battery (SLIC, FXS, DID, etc.) is inherently referenced to ground. The situation with a ground-start FXO interface is not much better. Do others in the group agree with this interpretation? If not, how are feed circuits supposed to be isolated? Does anyone have direct experience with getting a product through UL with these exemptions? I recognize that the original thread here related to network equipment, but the "permanent ground" exemption should apply to network equipment as well. I also recognize that these exemptions only apply to circuits that qualify as TNV, and do not address some of the other issues that Jim Weise raised concerning things like 200 volts DC for repeaters. However, for simple TNV isolation, it seems that network equipment could use the "permanent ground" exemptions from having to provide creepage and clearance (or in fact, any isolation at all). Any input from others in the group would be welcome. Joe Randolph Telecom Design Consultant Randolph Telecom, Inc. 781-721-2848 (USA) - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: "unsubscribe emc-pstc" (without the quotes). For help, send mail to ed.pr...@cubic.com, j...@gwmail.monarch.com, ri...@sd
Re: Network Equipment and UL 1459/1950
Jim, Your interpretaion is 100% correct. I have personally Listed many products with UL1950 Third Edition with a supplemental earthing terminal as you described below with no basic insulation between the TNV-2/TNV-3 circuits and SELV/Earth. The standard specifies that basic insulation is one way of complying with the requirements. Another way is as you describe in your e-mail and which I have used to Approve lots of equipment worldwide. However, the standard goes on to say "other solutions are not excluded". My question to you all does anyone have a design or could give some examples using "other solutions are not excluded"? PS - The IEC 950 WG7 Committe (Telecoms) is currently working on Remote Power Feeding Requirements. Some members of the committe are also from the US and Canada. We are working together to come up with solutions. A lot of work still remains and I am hopeful that within 2 years we should have common requirements (of course as usual, with deviations for member countries). I strongly feel that there is really no need to come up with a new standard for network equipment since the UL1950 will eventually have the remote power feed requirements included. Best Regards, > In a message dated 3/24/99, jim.wi...@adtran.com writes: > > > The only design criteria with regard to insulation in Bellcore standards or > UL 1459 is a hi-pots test. > > Creepage and clearance do not exist in traditional C.O. equipment (just look > at wire wrapped > > backplanes). > > > Dear Jim and others: > > Jim Wiese has raised several concerns regarding the transition from UL 1459 to > UL 1950 (3rd Edition). One of these concerns relates to the new creepage and > clearance requirements for separation of TNV circuits and ground/SELV. > > I would like to pick up on this one issue (I know that Jim has raised several > other issues as well). In particular, I would like some feedback from others > in the group regarding my interpretation of how the separation requirements in > UL 1950 apply to certain types of equipment. > > Just this week I met with a PBX manufacturer who is in the process of re- > designing the backplane and all of the line cards in their PBX to "comply with > UL 1950." The PBX is presently approved to UL 1459, but the manufacturer has > its eye on the March 2000 date for new or modified products to comply with UL > 1950. Needless to say, the redesign effort is an expensive one. > > The biggest headache in the redesign is complying with the creepage and > clearance distances for separation of TNV and SELV circuits. The PBX > manufacturer seemed incredulous when I stated that I did not think the > creepage and clearance requirements applied to their product, since the PBX > has a permanent (hardwired) connection to ground. My interpretation is based > primarily on the following statement in clause 6.2.1.2 in UL 1950, paraphrased > below: > > " Basic insulation is not required provided that all of the following > conditions are met: >- the SELV circuit is connected to protective earth...in accordance > with 2.5; and >- the installation instructions specifya permanent connection to earth; > and >- the test of 6.2.1.3 is carried out... (where applicable)" > > There are other clauses that call out isolation, such as 6.3.3.1 and 6.4.1, > but the "permanent ground" exemption appears to apply here as well. > > In my view, these exemptions are specifically targeted at equipment such as > PBXs and network equipment that are typically installed by service personnel > and include hardwired grounding. Without these exemptions, it is almost > impossible to separate certain types of TNV circuits from SELV and ground. > For example, a feed circuit that provides 48V battery (SLIC, FXS, DID, etc.) > is inherently referenced to ground. The situation with a ground-start FXO > interface is not much better. > > Do others in the group agree with this interpretation? If not, how are feed > circuits supposed to be isolated? Does anyone have direct experience with > getting a product through UL with these exemptions? > > I recognize that the original thread here related to network equipment, but > the "permanent ground" exemption should apply to network equipment as well. I > also recognize that these exemptions only apply to circuits that qualify as > TNV, and do not address some of the other issues that Jim Weise raised > concerning things like 200 volts DC for repeaters. However, for simple TNV > isolation, it seems that network equipment could use the "permanent ground" > exemptions from having to provide creepage and clearance (or in fact, any > isolation at all). > > Any input from others in the group would be welcome. > > > Joe Randolph > Telecom Design Consultant > Randolph Telecom, Inc. > 781-721-2848 (USA) > > - > This message is coming from the emc-pstc discussion list. > To cancel your subscription, send mail to majord...@ieee.or
RE: Network Equipment and UL 1459/1950
We just completed an approval with the exact same situation. I cannot speak for your prodcut since I have not reviewed it. I can provide a contact at UL if required. One of the big concerns is the R/C connectors normally used for bringing the lines in do not even meet UL1950 unless pins are skipped. Best Regards, Jody Leber jle...@ustech-lab.com http://www.ustech-lab.com U. S. Technologies 3505 Francis Circle Alpharetta, GA 30004 770.740.0717 Fax: 770.740.1508 -Original Message- From: j...@aol.com [SMTP:j...@aol.com] Sent: Wednesday, March 24, 1999 3:42 PM To: emc-pstc; 'TREG' Cc: jim.wi...@adtran.com Subject: Re: Network Equipment and UL 1459/1950 In a message dated 3/24/99, jim.wi...@adtran.com writes: > The only design criteria with regard to insulation in Bellcore standards or UL 1459 is a hi-pots test. > Creepage and clearance do not exist in traditional C.O. equipment (just look at wire wrapped > backplanes). Dear Jim and others: Jim Wiese has raised several concerns regarding the transition from UL 1459 to UL 1950 (3rd Edition). One of these concerns relates to the new creepage and clearance requirements for separation of TNV circuits and ground/SELV. I would like to pick up on this one issue (I know that Jim has raised several other issues as well). In particular, I would like some feedback from others in the group regarding my interpretation of how the separation requirements in UL 1950 apply to certain types of equipment. Just this week I met with a PBX manufacturer who is in the process of re- designing the backplane and all of the line cards in their PBX to "comply with UL 1950." The PBX is presently approved to UL 1459, but the manufacturer has its eye on the March 2000 date for new or modified products to comply with UL 1950. Needless to say, the redesign effort is an expensive one. The biggest headache in the redesign is complying with the creepage and clearance distances for separation of TNV and SELV circuits. The PBX manufacturer seemed incredulous when I stated that I did not think the creepage and clearance requirements applied to their product, since the PBX has a permanent (hardwired) connection to ground. My interpretation is based primarily on the following statement in clause 6.2.1.2 in UL 1950, paraphrased below: " Basic insulation is not required provided that all of the following conditions are met: - the SELV circuit is connected to protective earth...in accordance with 2.5; and - the installation instructions specifya permanent connection to earth; and - the test of 6.2.1.3 is carried out... (where applicable)" There are other clauses that call out isolation, such as 6.3.3.1 and 6.4.1, but the "permanent ground" exemption appears to apply here as well. In my view, these exemptions are specifically targeted at equipment such as PBXs and network equipment that are typically installed by service personnel and include hardwired grounding. Without these exemptions, it is almost impossible to separate certain types of TNV circuits from SELV and ground. For example, a feed circuit that provides 48V battery (SLIC, FXS, DID, etc.) is inherently referenced to ground. The situation with a ground-start FXO interface is not much better. Do others in the group agree with this interpretation? If not, how are feed circuits supposed to be isolated? Does anyone have direct experience with getting a product through UL with these exemptions? I recognize that the original thread here related to network equipment, but the "permanent ground" exemption should apply to network equipment as well. I also recognize that these exemptions only apply to circuits that qualify as TNV, and do not address some of the other issues that Jim Weise raised concerning things like 200 volts DC for repeaters. However, for simple TNV isolation, it seems that network equipment could use the "permanent ground" exemptions from having to provide creepage and clearance (or in fact, any isolation at all). Any input from others in the group would be welcome. Joe Randolph Telecom Design Consultant Randolph Telecom, Inc. 781-721-2848 (USA) - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: "unsubscribe emc-pstc" (without the quotes). For help, send mail to ed.pr...@cubic.com, j...@gwmail.monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators). - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: "unsubscribe emc-pstc" (without the quotes). For help, send mail to ed.pr...@cubic.com, j...@gwmail.monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
Re: Network Equipment and UL 1459/1950
Message text written by INTERNET:t...@world.std.com >In my view, these exemptions are specifically targeted at equipment such as PBXs and network equipment that are typically installed by service personnel and include hardwired grounding.< When Telecom equipment (of the non-network equipment variety) was included under IEC 950 it was a hard sell to the Data Processing equipment manufacturers, who did not want to see their Data Processing equipment standard polluted by telecom considerations. In addition, the telecom reps where not really PBX experts of any sort (with one exception). Therefore, in trying to interpret IEC 60950, one cannot assume that PBX and network equipment was targetted. There was a basic assumption that if the Mainframe computer and router equipment manufacturers could do it, than the telecom equipment manufacturers ought to be able to do it, over time. On another note, a lot of these type of requirements come from so-called, horizontal standards developed by other experts who have no knowledge of either Information or Communications technology practices. If you want to change these "horizontal" standards, you have to join that crowd for years till they have confidence in you, and than you might be able to change some of those things. By and large, one cannot get money for that sort of a campaign in the ICT industry. Therefore, you have to live with it. When we started the campaign for IEC950, CO voltages and currents were considered dangerous and one would have had to run telecom installations in conduit. We've come a long way. Ciao, Vic
Re: Network Equipment and UL 1459/1950
In a message dated 3/24/99, jim.wi...@adtran.com writes: > The only design criteria with regard to insulation in Bellcore standards or UL 1459 is a hi-pots test. > Creepage and clearance do not exist in traditional C.O. equipment (just look at wire wrapped > backplanes). Dear Jim and others: Jim Wiese has raised several concerns regarding the transition from UL 1459 to UL 1950 (3rd Edition). One of these concerns relates to the new creepage and clearance requirements for separation of TNV circuits and ground/SELV. I would like to pick up on this one issue (I know that Jim has raised several other issues as well). In particular, I would like some feedback from others in the group regarding my interpretation of how the separation requirements in UL 1950 apply to certain types of equipment. Just this week I met with a PBX manufacturer who is in the process of re- designing the backplane and all of the line cards in their PBX to "comply with UL 1950." The PBX is presently approved to UL 1459, but the manufacturer has its eye on the March 2000 date for new or modified products to comply with UL 1950. Needless to say, the redesign effort is an expensive one. The biggest headache in the redesign is complying with the creepage and clearance distances for separation of TNV and SELV circuits. The PBX manufacturer seemed incredulous when I stated that I did not think the creepage and clearance requirements applied to their product, since the PBX has a permanent (hardwired) connection to ground. My interpretation is based primarily on the following statement in clause 6.2.1.2 in UL 1950, paraphrased below: " Basic insulation is not required provided that all of the following conditions are met: - the SELV circuit is connected to protective earth...in accordance with 2.5; and - the installation instructions specifya permanent connection to earth; and - the test of 6.2.1.3 is carried out... (where applicable)" There are other clauses that call out isolation, such as 6.3.3.1 and 6.4.1, but the "permanent ground" exemption appears to apply here as well. In my view, these exemptions are specifically targeted at equipment such as PBXs and network equipment that are typically installed by service personnel and include hardwired grounding. Without these exemptions, it is almost impossible to separate certain types of TNV circuits from SELV and ground. For example, a feed circuit that provides 48V battery (SLIC, FXS, DID, etc.) is inherently referenced to ground. The situation with a ground-start FXO interface is not much better. Do others in the group agree with this interpretation? If not, how are feed circuits supposed to be isolated? Does anyone have direct experience with getting a product through UL with these exemptions? I recognize that the original thread here related to network equipment, but the "permanent ground" exemption should apply to network equipment as well. I also recognize that these exemptions only apply to circuits that qualify as TNV, and do not address some of the other issues that Jim Weise raised concerning things like 200 volts DC for repeaters. However, for simple TNV isolation, it seems that network equipment could use the "permanent ground" exemptions from having to provide creepage and clearance (or in fact, any isolation at all). Any input from others in the group would be welcome. Joe Randolph Telecom Design Consultant Randolph Telecom, Inc. 781-721-2848 (USA) - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: "unsubscribe emc-pstc" (without the quotes). For help, send mail to ed.pr...@cubic.com, j...@gwmail.monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
RE: Network Equipment and UL 1459/1950
A couple of comments: -As Randy and Jim Brunssen will recall, an exhaustive comparison of UL 950 and 1459 took place under TR 41.7.1 For those who still have the paperwork, reams of rationale still abound. This comparison, and the harmonization of UL 1459 and CSA Standard C22.2 No. 225, were the first steps in the harmonisation with IEC 950(now 60950), UL 1950 and C22.2 No. 950. -We in Canada did not have the advantage of Bellcore specs. We therefore had to rely on the Canadian equivalent of 1459, C22.2 No 225, to specify what we wanted in the way of safety. Thus, when Bell Canada no longer was able to look on Nortel Networks as a private in-house supplier who designed to our requirements, (and also began buying from other sources), the only way to specify safety was by referencing CSA standards in purchase specs. 225 was it. -The question of what forms a telecom network is one that borders on philosophy, rather than being technical. 'Network' equipment on customer premises, such as remotes, is clearly included; some would include the telephone set as well. The question of jurisdiction, not technical requirements, limit 60950/1950/950 to a subscriber's installation. -Meeting these standards should not be a surprise to suppliers who sold in Canada. The documents were made fully usable for network equipment, because only network equipment used by certain carriers is exempt from listing/certification and inspection. In Canada, for those seeking network equipment certification, it was the only show in town. Probably in the US as well. -As stated, the main difference between the international standards, which came primarily from the IT industry, and the Telecom standards, was the measurement of clearances/creepages as opposed to checking for the functional equivalent through dielectric tests. But when the various groups set out to harmonize internationally, it was spelled out that 1459, with this different approach, was going to be withdrawn. The writing was on the wall that something would have to change. -As for the question of the higher voltages, the separation of 'raw ringing' (the old slip-ring ringing generators are long gone), and trippable ringing by a 'ring-trip relay' or its modern equivalent was the subject of much debate. This question applies as well to the ringing generated in a PBX. -Other high voltages do exist in telecom equipment, as Jim Weiss stated, and are used to power other equipment. These voltages cannot be considered as other than hazardous, and should therefore not be accessible in a user access area. As for where that leaves suppliers faced with the withdrawal of 1459, surely, if some suppliers have not prepared for this change, the solution would be a postponement of the DOW of 1459, not its re-establishment (which would require updates, etc., and hamper international trade). Regards, Frank McCaughey - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: "unsubscribe emc-pstc" (without the quotes). For help, send mail to ed.pr...@cubic.com, j...@gwmail.monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
RE: Network Equipment and UL 1459/1950
To emphasis Tania's comments about the telco not providing the hardware, its conceivable that this message got to you without using telco equipment, at least in the traditional sense. It use to be that digital signals were sent over voice lines. Now voice is sent over digital lines and can be done completely without the teleco's involved. We're doing right here, in Spokane Wa. on a metropolitan are for the school district and we and other are doing it elsewhere. The school district is saving $500,000 to $800,000 a year (I listened and believed one of our marketing guys - forgive me the sin if the numbers aren't quite right) in telephone costs. The district staff doesn't know the difference, nor do they even realize that they are doing interesting high tech stuff when they pick up the phone and order video on demand and get it down the same pipe they just spoke through. Sorry, this wasn't meant to be an ad - just a solid reinforcement of Tania's remarks on who makes the equipment. The need for dancing solely to the telco's music is changing. Simply because they don't want the standards harmonized is no longer sufficient to halt it. Just as office equipment and computer equipment became indistinguishable from one another, the evolution between telco equipment and digital transmission such as Ethernet, sonnet and ATM is becoming indistinguishable and should drive the harmonizing of standards. There are two critical points in this tread safety and reliability. I would support the Teleco's absolute adherence to reliability. When all else fails in an emergency, pick up the phone. I'm betting you have a dial tone. What I don't see is how the harmonizing of standards to that used for this equipment throughout the world, computers and Ethernet, but outside of the telco's direct ability to control would reduce that reliability. In point of fact they have a whole additional layer of tests in the NEBS series that insure that reliability. The comment about reduced spacings and relying on dielectric tests instead. Isn't that still an option in 1950? Gary Obviously, these are my opinions and not necessarily that of my employer who may or may not smote me about the head and shoulders for making them. Hmmm, my phone line just mysteriously went dead! -Original Message- From: Grant, Tania (Tania) [SMTP:tgr...@lucent.com] Sent: Tuesday, March 23, 1999 8:32 PM To: emc-pstc; 'TREG'; NEBS FORUM; 'JIM WIESE' Cc: Ron Bernot; Randy Ivans; Mark Vlanich; Jim Brunssen; Tom Burke; Kevin Ravo; 'MARK WALKER'; Bob Burek; Tom_Amatulli; Frank Terlato; Bob Raskey; harry.vanza...@telops.gte.com; chuck_gr...@smtp.nynex.com; tto...@uswest.com; jmla...@uswest.com; mben...@uswest.com; sbi...@hotmail.com; Larry Todd; Keith Kuhn Subject:RE: Network Equipment and UL 1459/1950 Jim, Thank you for giving us an opportunity to respond. It would have been very helpful if the telco providers referenced in your e-mail were more specific as to why they cannot "harmonize" with UL1950 requirements. By specific, I mean paragraph by paragraph. But let me guess from the few statements that you have made. They cite cost and the added requirement of measuring creepage and clearance rather than just performing the dielectric strength tests. I have a response to that. The telco providers to the public are no longer providing the hardware; they are purchasing it from other hardware companies that are not providing telco connections to the public. These hardware providers are providing equipment to world-wide customers. These customers are requiring IEC950 derivative standards. Those of us selling internationally are designing and meeting UL1950/IEC950 requirements. To us, the increased cost to design to two different standards and/or to submit equipment twice for testing to two different standards is an undue and unnecessary burden. Whose cost is greater, can be debated, but I don't think that would resolve anything. I think, however, that it should be stated that in either case, there is cost involved to both parties. Thus, we are adamantly opposed to UL's proposal (your 4th paragraph) that UL1459 be "revived" for network equipment only. UL should realize that the traditional "telco providers" are not at the forefront of industry technology;-- the future is sophisticated PC applications and servers interconnecting the world utilizing voice, Internet, Ethernet, and fast data links. This is indeed "information technology equipment", whether it be located in a central office telephone switch room or in a hospital, bank, or university. The location no longer should matter;--
RE: Network Equipment and UL 1459/1950
ork and makes up the TELCO PROVIDERS installation (not the subscribers) and is exempt. In short, there is no UL safety standard that covers network equipment at this time. Although some newer types network equipment might be capable of being Listed to UL 1950. Jim Jim Wiese Compliance Engineer ADTRAN, INC. 901 Explorer Blvd. P.O. Box 14 Huntsville, AL 35814-4000 256-963-8431 256-963-8250 fax jim.wi...@adtran.com > -- > From: Grant, Tania (Tania)[SMTP:tgr...@lucent.com] > Sent: Tuesday, March 23, 1999 10:32 PM > To: emc-pstc; 'TREG'; NEBS FORUM; 'JIM WIESE' > Cc: Ron Bernot; Randy Ivans; Mark Vlanich; Jim Brunssen; Tom Burke; > Kevin Ravo; 'MARK WALKER'; Bob Burek; Tom_Amatulli; Frank Terlato; Bob > Raskey; harry.vanza...@telops.gte.com; chuck_gr...@smtp.nynex.com; > tto...@uswest.com; jmla...@uswest.com; mben...@uswest.com; > sbi...@hotmail.com; Larry Todd; Keith Kuhn > Subject: RE: Network Equipment and UL 1459/1950 > > Jim, > > Thank you for giving us an opportunity to respond. > > It would have been very helpful if the telco providers referenced in your > e-mail were more specific as to why they cannot "harmonize" with UL1950 > requirements. By specific, I mean paragraph by paragraph. But let me > guess > from the few statements that you have made. They cite cost and the added > requirement of measuring creepage and clearance rather than just > performing > the dielectric strength tests. I have a response to that. > > The telco providers to the public are no longer providing the hardware; > they > are purchasing it from other hardware companies that are not providing > telco > connections to the public. These hardware providers are providing > equipment > to world-wide customers. These customers are requiring IEC950 derivative > standards. Those of us selling internationally are designing and meeting > UL1950/IEC950 requirements. To us, the increased cost to design to two > different standards and/or to submit equipment twice for testing to two > different standards is an undue and unnecessary burden. Whose cost is > greater, can be debated, but I don't think that would resolve anything. I > think, however, that it should be stated that in either case, there is > cost > involved to both parties. > > Thus, we are adamantly opposed to UL's proposal (your 4th paragraph) that > UL1459 be "revived" for network equipment only. UL should realize that > the > traditional "telco providers" are not at the forefront of industry > technology;-- the future is sophisticated PC applications and servers > interconnecting the world utilizing voice, Internet, Ethernet, and fast > data > links. This is indeed "information technology equipment", whether it be > located in a central office telephone switch room or in a hospital, bank, > or > university. The location no longer should matter;-- safety of the > equipment does matter. And safety should not be relative to geography > (humidity excepted!) > > To alleviate the burden of increased costs for those few hardware > providers > who are not selling to the international market, I offer the following > recommendations: > > * Extend or retain UL1459 for the domestic U.S. market only, provided > the UL1950/IEC950 harmonized requirements remain an option to those of us > who wish to ship internationally. It should be noted that Canada (unless > they change their minds dramatically) has harmonized with IEC950 earlier > than UL and, I don't believe, would consider going back to C22.2, No.220. > > or > > * Add another Appendix to UL1950, similar to NAE, that would list > UL1459 only options in lieu of the stated UL1950/IEC950 requirements. > During UL product evaluation, a statement could be added under Engineering > Considerations that this product meets only U.S. requirements. Under > those > circumstances, obviously, UL would never consider providing a CB Scheme > Report and Certificate. The rest of us will happily take UL1950 and the > CB > Scheme Report. > > I believe that by considering either of the above two options, UL can make > both parties happy. But please, do not "revive" UL1459 for telephone > equipment and punish the rest of us. > > Tania Grant, Lucent Technologies, Octel Messaging Division > tgr...@lucent.com > > > -- > > From: JIM WIESE[SMTP:jim.wi...@adtran.com] > > Reply To: JIM WIESE > > Sent: Monday, March 22, 1999 4:06 PM > > To: emc-pstc; 'TREG'; NEBS FORUM > > Cc: Ron Bernot; Randy Ivans; Mark Vlanich;
RE: Network Equipment and UL 1459/1950
Jim, Thank you for giving us an opportunity to respond. It would have been very helpful if the telco providers referenced in your e-mail were more specific as to why they cannot "harmonize" with UL1950 requirements. By specific, I mean paragraph by paragraph. But let me guess from the few statements that you have made. They cite cost and the added requirement of measuring creepage and clearance rather than just performing the dielectric strength tests. I have a response to that. The telco providers to the public are no longer providing the hardware; they are purchasing it from other hardware companies that are not providing telco connections to the public. These hardware providers are providing equipment to world-wide customers. These customers are requiring IEC950 derivative standards. Those of us selling internationally are designing and meeting UL1950/IEC950 requirements. To us, the increased cost to design to two different standards and/or to submit equipment twice for testing to two different standards is an undue and unnecessary burden. Whose cost is greater, can be debated, but I don't think that would resolve anything. I think, however, that it should be stated that in either case, there is cost involved to both parties. Thus, we are adamantly opposed to UL's proposal (your 4th paragraph) that UL1459 be "revived" for network equipment only. UL should realize that the traditional "telco providers" are not at the forefront of industry technology;-- the future is sophisticated PC applications and servers interconnecting the world utilizing voice, Internet, Ethernet, and fast data links. This is indeed "information technology equipment", whether it be located in a central office telephone switch room or in a hospital, bank, or university. The location no longer should matter;-- safety of the equipment does matter. And safety should not be relative to geography (humidity excepted!) To alleviate the burden of increased costs for those few hardware providers who are not selling to the international market, I offer the following recommendations: * Extend or retain UL1459 for the domestic U.S. market only, provided the UL1950/IEC950 harmonized requirements remain an option to those of us who wish to ship internationally. It should be noted that Canada (unless they change their minds dramatically) has harmonized with IEC950 earlier than UL and, I don't believe, would consider going back to C22.2, No.220. or * Add another Appendix to UL1950, similar to NAE, that would list UL1459 only options in lieu of the stated UL1950/IEC950 requirements. During UL product evaluation, a statement could be added under Engineering Considerations that this product meets only U.S. requirements. Under those circumstances, obviously, UL would never consider providing a CB Scheme Report and Certificate. The rest of us will happily take UL1950 and the CB Scheme Report. I believe that by considering either of the above two options, UL can make both parties happy. But please, do not "revive" UL1459 for telephone equipment and punish the rest of us. Tania Grant, Lucent Technologies, Octel Messaging Division tgr...@lucent.com > -- > From: JIM WIESE[SMTP:jim.wi...@adtran.com] > Reply To: JIM WIESE > Sent: Monday, March 22, 1999 4:06 PM > To: emc-pstc; 'TREG'; NEBS FORUM > Cc: Ron Bernot; Randy Ivans; Mark Vlanich; Jim Brunssen; Tom Burke; > Kevin Ravo; 'MARK WALKER'; Bob Burek; Tom_Amatulli; Frank Terlato; Bob > Raskey; harry.vanza...@telops.gte.com; chuck_gr...@smtp.nynex.com; > tto...@uswest.com; jmla...@uswest.com; mben...@uswest.com; > sbi...@hotmail.com; Larry Todd; Keith Kuhn > Subject: Network Equipment and UL 1459/1950 > > TIA 41.7 and Underwriters Laboratories are interested in obtaining > information and input relating to concerns, complaints and problems with > the > cutover from UL 1459 to UL 1950 3rd Edition for equipment designed to be > owned, installed and maintained by a telecommunications provider. This is > equipment and installations that are traditionally exempt from the NEC, > but > could make up the demarcation point. The cutover is scheduled for March > 15th, 2000. > > Interest in telco providers having "safety listings" on new products they > purchase has grown rapidly in the last few years. Equipment installed by > the telco providers has traditionally been built utilizing design > guidelines > based on Bellcore standards (such as GR-1089-CORE), and/or UL 1459. As > many > of you know, UL 1950 3rd edition is based upon spacings called creepage > and > clearance. Traditional telco installations are deficient with regard to > creepage and clearance, but will meet the dielectric tests called out
Network Equipment and UL 1459/1950
TIA 41.7 and Underwriters Laboratories are interested in obtaining information and input relating to concerns, complaints and problems with the cutover from UL 1459 to UL 1950 3rd Edition for equipment designed to be owned, installed and maintained by a telecommunications provider. This is equipment and installations that are traditionally exempt from the NEC, but could make up the demarcation point. The cutover is scheduled for March 15th, 2000. Interest in telco providers having "safety listings" on new products they purchase has grown rapidly in the last few years. Equipment installed by the telco providers has traditionally been built utilizing design guidelines based on Bellcore standards (such as GR-1089-CORE), and/or UL 1459. As many of you know, UL 1950 3rd edition is based upon spacings called creepage and clearance. Traditional telco installations are deficient with regard to creepage and clearance, but will meet the dielectric tests called out in UL 1459. There are also substantial differences between GR-1089-CORE, UL 1459 and UL 1950 3rd with regard to voltage limits. In discussions with various telco providers over the past month, there has been a consensus that there is not a perception of safety problems and there is some concern that the ramifications of eliminating UL 1459 could have an undesired impact. They have stressed that harmonization is not a factor as the infrastructure used in North America is unique. They also stressed that they have 3 basic concerns with regard to safety listings; no increased cost to the product, can utilize existing shelves, housing, channel banks and infrastructure, the listing is to a standard that is acceptable into to foreseeable future. UL 1950 3rd Edition without some substantial deviations will not meet the needs of the telco providers. Work is currently ongoing at UL to determine if UL 1459 needs to be revived for network equipment, reissued under a new standard number with a revised scope for network equipment only, or develop deviations in UL 1950 3rd edition. As such, if you have any input, concerns or issues with the above mentioned topic, TIA 41.7.1 and UL would be very interested in your comments. They are trying to determine if there is industry support to look further into these issues. Please forward this E-mail to anybody you know that might be outside this mailing list that also might be interested. Please send comments, complaints, problems etc. to: 1.) Randy Ivans (chairman of TIA 41.7.1) iva...@ul.com 516-271-6200 ext. 22269 2.) Mark Vlanich (UL Engineering Team Leader) vlani...@ul.com 919-549-1647 3.) Jim Brunssen (Telcordia formerly Bellcore) jbrun...@notes.cc.bellcore.com 973-829-2977 4.) Or simply respond to me and I will present it to TIA in May Thanks, Jim Jim Wiese Compliance Engineer ADTRAN, INC. 901 Explorer Blvd. P.O. Box 14 Huntsville, AL 35814-4000 256-963-8431 256-963-8250 fax jim.wi...@adtran.com - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: "unsubscribe emc-pstc" (without the quotes). For help, send mail to ed.pr...@cubic.com, j...@gwmail.monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
