RE: Insulated Electrolytic Capacitors
It is my understanding the only X and Y type capacitors can be relied upon to provide basic insulation (my experience with IEC60065) >From bitter experience I have learned that you can't rely on other products (or even your own previously approved products) for verification of conformity. The test engineer may have missed something - apparently they're only human(?). Regards Chris Colgan Compliance Engineer TAG McLaren Audio Ltd The Summit, Latham Road Huntingdon, Cambs, PE29 6ZU *Tel: +44 (0)1480 415 627 *Fax: +44 (0)1480 52159 * Mailto:chris.col...@tagmclaren.com * http://www.tagmclaren.com > -Original Message- > From: Peter Merguerian [SMTP:pmerguer...@itl.co.il] > Sent: 24 October 2001 14:38 > To: "EMC-PSTC (E-mail)" < > Subject: Insulated Electrolytic Capacitors > > > Dear All, > > I have submitted an ac input to dc output switching power supply for NRTL > approval. One deviation is that the primary ac insulated capacitor is too > close to the earthed chassis and that the insulation cannot be relied to > provide the required basic insulation. > > 1. What is the group's opinion regarding this point? I have personally > seen > many Listed/Recognized units with clearance distance less than 2.0 mm to > the > earthed chassis without any additional insulation to provide the required > insulation. In fact, I am holding a switching power supply by a reputable > manufacturer with only approx. 0.7 mm between the primary and earthed > chassis. This power supply is UL Recognized and TUV approved. > > 2. There is a UL Pag 156002 regarding this issue, but it seems that some > NRTL engineers are using their own judgement and approving units at their > own discretion. > > > > > > This e-mail message may contain privileged or confidential information. If > you are not the intended recipient, you may not disclose, use, > disseminate, > distribute, copy or rely upon this message or attachment in any way. If > you > received this e-mail message in error, please return by forwarding the > message and its attachments to the sender. > > > > > PETER S. MERGUERIAN > Technical Director > I.T.L. (Product Testing) Ltd. > 26 Hacharoshet St., POB 211 > Or Yehuda 60251, Israel > Tel: + 972-(0)3-5339022 Fax: + 972-(0)3-5339019 > Mobile: + 972-(0)54-838175 > > > > > > > --- > 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: > majord...@ieee.org > with the single line: > unsubscribe emc-pstc > > For help, send mail to the list administrators: > Michael Garretson:pstc_ad...@garretson.org > Dave Healddavehe...@mediaone.net > > For policy questions, send mail to: > Richard Nute: ri...@ieee.org > Jim Bacher: j.bac...@ieee.org > > All emc-pstc postings are archived and searchable on the web at: > No longer online until our new server is brought online and the old > messages are imported into the new server. ** Please visit us at www.tagmclaren.com ** The contents of this E-mail are confidential and for the exclusive use of the intended recipient. If you receive this E-mail in error, please delete it from your system immediately and notify us either by E-mail, telephone or fax. You should not copy, forward or otherwise disclose the content of the E-mail. TAG McLaren Audio Ltd The Summit, 11 Latham Road Huntingdon, Cambs, PE29 6ZU Telephone : 01480 415600 (+44 1480 415600) Facsimile : 01480 52159 (+44 1480 52159) ** Please visit us at www.tagmclaren.com ** --- 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: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
Re: Insulated Electrolytic Capacitors
From: Douglas Beckwith@MITEL on 10/24/2001 02:05 PM Hi Peter, My understanding of 60950 is that distance through insulation applies here (0.4mm). I have never had this issue with CSA. Regards Doug Beckwith Mitel Networks Peter Merguerian on 10/24/2001 09:38:19 AM Please respond to Peter Merguerian To: "\"EMC-PSTC (E-mail)\" <" cc:(bcc: Douglas Beckwith/Kan/Mitel) Subject: Insulated Electrolytic Capacitors Dear All, I have submitted an ac input to dc output switching power supply for NRTL approval. One deviation is that the primary ac insulated capacitor is too close to the earthed chassis and that the insulation cannot be relied to provide the required basic insulation. 1. What is the group's opinion regarding this point? I have personally seen many Listed/Recognized units with clearance distance less than 2.0 mm to the earthed chassis without any additional insulation to provide the required insulation. In fact, I am holding a switching power supply by a reputable manufacturer with only approx. 0.7 mm between the primary and earthed chassis. This power supply is UL Recognized and TUV approved. 2. There is a UL Pag 156002 regarding this issue, but it seems that some NRTL engineers are using their own judgement and approving units at their own discretion. This e-mail message may contain privileged or confidential information. If you are not the intended recipient, you may not disclose, use, disseminate, distribute, copy or rely upon this message or attachment in any way. If you received this e-mail message in error, please return by forwarding the message and its attachments to the sender. PETER S. MERGUERIAN Technical Director I.T.L. (Product Testing) Ltd. 26 Hacharoshet St., POB 211 Or Yehuda 60251, Israel Tel: + 972-(0)3-5339022 Fax: + 972-(0)3-5339019 Mobile: + 972-(0)54-838175 --- 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: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server. --- 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: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
Re: Insulated Electrolytic Capacitors
Hi Peter: As a general rule, the insulation on the outside of an electrolytic capacitor is considered functional insulation. (Indeed, the insulation between the elements of the capacitor and the aluminum can is clearly functional insulation.) As far as I know, only X- and Y-capacitor insulation may be considered Basic insulation (in accordance with IEC 60384-14). Consequently, the insulation on the capacitor must be ignored. The distance between the capacitor case and grounded metal must meet the creepage and clearance distance requirements, or solid insulation must be interposed between the capacitor and the grounded metal. The fact that some certified power supplies do not meet the spacing requirements is not an argument that such spacings are not required. This simply means that neither the power supply safety engineer nor the certification engineer caught the problem. After all, the spacings within a power supply comprise a rather difficult and tedious job of identifying the various voltages and corresponding creepage and clearances on the PWB two-dimensional plane. Often, we don't look at the clearances in the third, vertical dimension. Best regards, Rich --- 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: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
AW: Insulated Electrolytic Capacitors
Peter, my experience is, that you will not receive a statement from the manufacturer of the capacitor about the foil around the cap. This would be required to proof, that it is good for basic insulation. Our company (we are a GS-mark certification body) does not accept the foil around a capacitor as basic insulation without proof. My experience with UL is, that UL is doing the same. The only way to accept the insulation of the capacitor would be to get a written statement from the capacitor manufacturer about the foil and describe this insulation in the list of safety critical components. With best regards Horst -Urspr?ngliche Nachricht- Von: owner-emc-p...@majordomo.ieee.org [mailto:owner-emc-p...@majordomo.ieee.org]Im Auftrag von Peter Merguerian Gesendet: Mittwoch, 24. Oktober 2001 15:38 An: "EMC-PSTC (E-mail)" < Betreff: Insulated Electrolytic Capacitors Dear All, I have submitted an ac input to dc output switching power supply for NRTL approval. One deviation is that the primary ac insulated capacitor is too close to the earthed chassis and that the insulation cannot be relied to provide the required basic insulation. 1. What is the group's opinion regarding this point? I have personally seen many Listed/Recognized units with clearance distance less than 2.0 mm to the earthed chassis without any additional insulation to provide the required insulation. In fact, I am holding a switching power supply by a reputable manufacturer with only approx. 0.7 mm between the primary and earthed chassis. This power supply is UL Recognized and TUV approved. 2. There is a UL Pag 156002 regarding this issue, but it seems that some NRTL engineers are using their own judgement and approving units at their own discretion. This e-mail message may contain privileged or confidential information. If you are not the intended recipient, you may not disclose, use, disseminate, distribute, copy or rely upon this message or attachment in any way. If you received this e-mail message in error, please return by forwarding the message and its attachments to the sender. PETER S. MERGUERIAN Technical Director I.T.L. (Product Testing) Ltd. 26 Hacharoshet St., POB 211 Or Yehuda 60251, Israel Tel: + 972-(0)3-5339022 Fax: + 972-(0)3-5339019 Mobile: + 972-(0)54-838175 --- 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: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server. --- 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: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
RE: Insulated Electrolytic Capacitors
I asked a similar question a couple of years ago, and was told that the bodies of plastic encapsulated Y1 capacitors are considered by CENELEC to be reinforced insulation, except in the vicinity of the leads. I don't know if this extends to types of X and Y caps other than Y1. Hope this is some help, Regards, Jim Eichner, P.Eng. Manager, Engineering Services Xantrex Technology Inc. Mobile Power web: www.xantrex.com <http://www.xantrex.com> Any opinions expressed are those of my invisible friend, who really exists. I know because he talks to me. Honest. -Original Message- From: Peter Merguerian [mailto:pmerguer...@itl.co.il] Sent: Wednesday, October 24, 2001 6:38 AM To: "EMC-PSTC (E-mail)" < Subject: Insulated Electrolytic Capacitors Dear All, I have submitted an ac input to dc output switching power supply for NRTL approval. One deviation is that the primary ac insulated capacitor is too close to the earthed chassis and that the insulation cannot be relied to provide the required basic insulation. 1. What is the group's opinion regarding this point? I have personally seen many Listed/Recognized units with clearance distance less than 2.0 mm to the earthed chassis without any additional insulation to provide the required insulation. In fact, I am holding a switching power supply by a reputable manufacturer with only approx. 0.7 mm between the primary and earthed chassis. This power supply is UL Recognized and TUV approved. 2. There is a UL Pag 156002 regarding this issue, but it seems that some NRTL engineers are using their own judgement and approving units at their own discretion. This e-mail message may contain privileged or confidential information. If you are not the intended recipient, you may not disclose, use, disseminate, distribute, copy or rely upon this message or attachment in any way. If you received this e-mail message in error, please return by forwarding the message and its attachments to the sender. PETER S. MERGUERIAN Technical Director I.T.L. (Product Testing) Ltd. 26 Hacharoshet St., POB 211 Or Yehuda 60251, Israel Tel: + 972-(0)3-5339022 Fax: + 972-(0)3-5339019 Mobile: + 972-(0)54-838175 --- 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: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server. --- 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: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
Re: Insulated Electrolytic Capacitors
Our company manufactures switching power supplies to EN60950 and EN60601-1 standards, and our safety group looks for these issues. In fact, I got 'bit' by that same problem last week. Spacing was OK when the PWB was mounted in the chassis, but when the cover was installed, it failed primary-ground spacing. I had to fix it. As far as the sample power supplies you have: - What safety standard does the manufacturer claim? - What are the installation instructions, or 'conditions of acceptability'? - Did they look as if they had been modified or installed in another chassis assembly after it was manufactured? On Wed, 24 Oct 2001 15:38:19 +0200, Peter Merguerian wrote: >I have submitted an ac input to dc output switching power supply for NRTL >approval. One deviation is that the primary ac insulated capacitor is too >close to the earthed chassis and that the insulation cannot be relied to >provide the required basic insulation. > >1. What is the group's opinion regarding this point? I have personally seen >many Listed/Recognized units with clearance distance less than 2.0 mm to the >earthed chassis without any additional insulation to provide the required >insulation. In fact, I am holding a switching power supply by a reputable >manufacturer with only approx. 0.7 mm between the primary and earthed >chassis. This power supply is UL Recognized and TUV approved. > >2. There is a UL Pag 156002 regarding this issue, but it seems that some >NRTL engineers are using their own judgement and approving units at their >own discretion. --- 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: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
Insulated Electrolytic Capacitors
Dear All, I have submitted an ac input to dc output switching power supply for NRTL approval. One deviation is that the primary ac insulated capacitor is too close to the earthed chassis and that the insulation cannot be relied to provide the required basic insulation. 1. What is the group's opinion regarding this point? I have personally seen many Listed/Recognized units with clearance distance less than 2.0 mm to the earthed chassis without any additional insulation to provide the required insulation. In fact, I am holding a switching power supply by a reputable manufacturer with only approx. 0.7 mm between the primary and earthed chassis. This power supply is UL Recognized and TUV approved. 2. There is a UL Pag 156002 regarding this issue, but it seems that some NRTL engineers are using their own judgement and approving units at their own discretion. This e-mail message may contain privileged or confidential information. If you are not the intended recipient, you may not disclose, use, disseminate, distribute, copy or rely upon this message or attachment in any way. If you received this e-mail message in error, please return by forwarding the message and its attachments to the sender. PETER S. MERGUERIAN Technical Director I.T.L. (Product Testing) Ltd. 26 Hacharoshet St., POB 211 Or Yehuda 60251, Israel Tel: + 972-(0)3-5339022 Fax: + 972-(0)3-5339019 Mobile: + 972-(0)54-838175 --- 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: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
