Re: [PSES] question with regard of inverter
The 800 lb gorilla should learn to read and check the applicable standard. (assuming 62109 was applicable for that equipment) And, I thought the only 800 lb gorillas were the electric utilities. ;-)) ___ Ralph McDiarmid | Schneider Electric | Solar Business | CANADA | Regulatory Compliance Engineering From: Pete Perkins 0061f3f32d0c-dmarc-requ...@ieee.org To: EMC-PSTC@LISTSERV.IEEE.ORG, Date: 08/08/2014 05:47 PM Subject: Re: [PSES] question with regard of inverter Peter, All well and good per IEC 62109 however the 800lb gorilla NRTL assessed the PV DC current monitor assembly (a piece of measurment equipment) to be OV CAT IV when it was assessed for certification. The manufacturer grumbled somewhat (since it wasn't designed for that OV category) but agreed that it was probably appropriate, as did I. :) br, Pete Peter E Perkins, PE Principal Product Safety Engineer PO Box 23427 Tigard, ORe 97281-3427 503/452-1201 fone/fax p.perk...@ieee.org From: Peter Tarver [mailto:ptar...@enphaseenergy.com] Sent: Friday, August 08, 2014 3:47 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] question with regard of inverter IEC 62109-1 considers “PV circuits in general” to be OVCII. Regards, Peter Tarver From: McDiarmid, Ralph [mailto:ralph.mcdiar...@schneider-electric.com] Sent: Friday, August 08, 2014 13:57 To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] question with regard of inverter My understanding as well, namely, OV categorization in power distribution is based on indirect (near-by) lightning strikes. ___ Ralph McDiarmid | Schneider Electric | Solar Business | CANADA | Regulatory Compliance Engineering From: John Woodgate j...@jmwa.demon.co.uk To: EMC-PSTC@LISTSERV.IEEE.ORG, Date: 08/06/2014 01:53 PM Subject: Re: [PSES] question with regard of inverter In message 53e28a32.4020...@ieee.org, dated Wed, 6 Aug 2014, Richard Nute ri...@ieee.org writes: . Your solar cell DC source is not subject to load switching, but is subject to a direct lightning strike. Your DC OVC due to load switching is zero, and your OVC due to lightning is beyond OVC IV. Is resistance to a direct lighting strike required of civilian products? I though that only 'indirect strike' was to be resisted, and OVC IV was based on that. -- OOO - Own Opinions Only. With best wishes. See www.jmwa.demon.co.uk Quid faciamus nisi sit? John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@radiusnorth.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com __ This email has been scanned by the Symantec Email Security.cloud service. __ - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@radiusnorth.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher j.bac...@ieee.org David Heald dhe...@gmail.com This email message is for the sole use of the intended recipient(s) and may contain confidential and/or privileged information. If you are not an intended recipient, you may not review, use, copy, disclose or distribute this message. If you received this message
Re: [PSES] question with regard of inverter
Dear Rich, dear Doug Thank you very much for your professional answer. I really appreciate it. It helps me a lot and also to my client. One more question, is there any expert in this group who has real experience with new Hazard Based Standard IEC 62368-1? We are currently working on few projects and i think that some requirements are not really clear. Best regards, Bostjan Boštjan Glavič Vodja laboratorija, Laboratorij za elektroniko Head of Laboratory, Laboratory of Electronic Engineering [SIQlogo60px] www.siq.sihttp://www.siq.si/ SIQ Ljubljana, Trzaska c. 2, SI-1000 Ljubljana, Slovenia, VAT ID: SI23509678 t +386 (0)1 4778 265tel:+386%20(0)1%204778%20265, m +386 (0)41 391 283tel:+386%20(0)41%20391%20283, f +386 (0)1 4778 444tel:+386%20(0)1%204778%20444 On 6. avg. 2014, at 22:04, Richard Nute ri...@ieee.orgmailto:ri...@ieee.org wrote: Dear Boštjan: If the solar cells are hit by lightning, then the DC and inverter system will likely be destroyed, and the transient will propagate into the AC system. There is no way to protect against a direct lightning strike except to use a system of lightning rods, and they may not provide protection against propagation. Except for a direct lightning strike, no transients appear on the DC side, so OVC does not apply. The 120/240 V AC probably is OVC III, and maybe OVC IV. Since there is no isolation between the AC and the DC, both will see the same AC transients. Your DC side should use the same OVC as the AC side. In my opinion, UL has not fully studied IEC 60664 which is the definitive standard for OVC. UL has extended the OVC requirements to DC without researching the origin and value of transients on DC mains and instead has simply applied the AC OVC to DC mains. According to IEC 60664 and other authorities such as Francois Martzloff, transients on AC systems come from two sources, lightning and load switching. Your solar cell DC source is not subject to load switching, but is subject to a direct lightning strike. Your DC OVC due to load switching is zero, and your OVC due to lightning is beyond OVC IV. Some references: http://www.metrel.si/dl?d=PDF_dokumentacija/White_papers/Ang/White_paper_Overvoltages_and_high_current_breakdowns.pdf http://www.denverpels.org/Downloads/Denver_PELS_20090915_Aldous_Insulation_Coordination.pdf Best regards, Rich On 8/6/2014 11:25 AM, Boštjan Glavič wrote: Dear Rich, Thank you. DC input comes from solar cells therefore from outside. UL 1741 states that OVC IV needs to be used and for 120/240V it means 4000V. So what transient should I use from DC side? Why table 8.1 in UL840 also mentions dc input? Best regards, Bostjan Boštjan Glavič Vodja laboratorija, Laboratorij za elektroniko Head of Laboratory, Laboratory of Electronic Engineering - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@radiusnorth.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com
Re: [PSES] question with regard of inverter
Bostjan, I would suggest you begin by reviewing this article at the IEC. http://www.iec.ch/etech/2013/etech_0313/tech-2.htm Thanks, - doug Douglas Powell http://www.linkedin.com/in/dougp01 Original Message From: Boštjan Glavič Sent: Friday, August 8, 2014 8:51 AM To: EMC-PSTC@LISTSERV.IEEE.ORG Reply To: Boštjan Glavič Subject: Re: [PSES] question with regard of inverter Dear Rich, dear Doug Thank you very much for your professional answer. I really appreciate it. It helps me a lot and also to my client. One more question, is there any expert in this group who has real experience with new Hazard Based Standard IEC 62368-1? We are currently working on few projects and i think that some requirements are not really clear. Best regards, Bostjan Boštjan Glavič Vodja laboratorija, Laboratorij za elektroniko Head of Laboratory, Laboratory of Electronic Engineering [SIQlogo60px] www.siq.sihttp://www.siq.si/ SIQ Ljubljana, Trzaska c. 2, SI-1000 Ljubljana, Slovenia, VAT ID: SI23509678 t +386 (0)1 4778 265tel:+386%20(0)1%204778%20265, m +386 (0)41 391 283tel:+386%20(0)41%20391%20283, f +386 (0)1 4778 444tel:+386%20(0)1%204778%20444 On 6. avg. 2014, at 22:04, Richard Nute ri...@ieee.orgmailto:ri...@ieee.org wrote: Dear Boštjan: If the solar cells are hit by lightning, then the DC and inverter system will likely be destroyed, and the transient will propagate into the AC system. There is no way to protect against a direct lightning strike except to use a system of lightning rods, and they may not provide protection against propagation. Except for a direct lightning strike, no transients appear on the DC side, so OVC does not apply. The 120/240 V AC probably is OVC III, and maybe OVC IV. Since there is no isolation between the AC and the DC, both will see the same AC transients. Your DC side should use the same OVC as the AC side. In my opinion, UL has not fully studied IEC 60664 which is the definitive standard for OVC. UL has extended the OVC requirements to DC without researching the origin and value of transients on DC mains and instead has simply applied the AC OVC to DC mains. According to IEC 60664 and other authorities such as Francois Martzloff, transients on AC systems come from two sources, lightning and load switching. Your solar cell DC source is not subject to load switching, but is subject to a direct lightning strike. Your DC OVC due to load switching is zero, and your OVC due to lightning is beyond OVC IV. Some references: http://www.metrel.si/dl?d=PDF_dokumentacija/White_papers/Ang/White_paper_Overvoltages_and_high_current_breakdowns.pdf http://www.denverpels.org/Downloads/Denver_PELS_20090915_Aldous_Insulation_Coordination.pdf Best regards, Rich On 8/6/2014 11:25 AM, Boštjan Glavič wrote: Dear Rich, Thank you. DC input comes from solar cells therefore from outside. UL 1741 states that OVC IV needs to be used and for 120/240V it means 4000V. So what transient should I use from DC side? Why table 8.1 in UL840 also mentions dc input? Best regards, Bostjan Boštjan Glavič Vodja laboratorija, Laboratorij za elektroniko Head of Laboratory, Laboratory of Electronic Engineering - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@radiusnorth.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@radiusnorth.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com
Re: [PSES] question with regard of inverter
Doug, I did, also many other documents like UL technical briefs. I have exact technical questions. Maybe I prepare a new email and list some of them. Best regards, Bostjan Boštjan Glavič Vodja laboratorija, Laboratorij za elektroniko Head of Laboratory, Laboratory of Electronic Engineering [SIQlogo60px] www.siq.sihttp://www.siq.si/ SIQ Ljubljana, Trzaska c. 2, SI-1000 Ljubljana, Slovenia, VAT ID: SI23509678 t +386 (0)1 4778 265tel:+386%20(0)1%204778%20265, m +386 (0)41 391 283tel:+386%20(0)41%20391%20283, f +386 (0)1 4778 444tel:+386%20(0)1%204778%20444 On 8. avg. 2014, at 16:59, Doug Powell doug...@gmail.commailto:doug...@gmail.com wrote: Bostjan, I would suggest you begin by reviewing this article at the IEC. http://www.iec.ch/etech/2013/etech_0313/tech-2.htm Thanks, - doug Douglas Powell http://www.linkedin.com/in/dougp01 Original Message From: Boštjan Glavič Sent: Friday, August 8, 2014 8:51 AM To: EMC-PSTC@LISTSERV.IEEE.ORGmailto:EMC-PSTC@LISTSERV.IEEE.ORG Reply To: Boštjan Glavič Subject: Re: [PSES] question with regard of inverter Dear Rich, dear Doug Thank you very much for your professional answer. I really appreciate it. It helps me a lot and also to my client. One more question, is there any expert in this group who has real experience with new Hazard Based Standard IEC 62368-1? We are currently working on few projects and i think that some requirements are not really clear. Best regards, Bostjan Boštjan Glavič Vodja laboratorija, Laboratorij za elektroniko Head of Laboratory, Laboratory of Electronic Engineering [SIQlogo60px] www.siq.sihttp://www.siq.sihttp://www.siq.si/ SIQ Ljubljana, Trzaska c. 2, SI-1000 Ljubljana, Slovenia, VAT ID: SI23509678 t +386 (0)1 4778 265tel:+386%20(0)1%204778%20265, m +386 (0)41 391 283tel:+386%20(0)41%20391%20283, f +386 (0)1 4778 444tel:+386%20(0)1%204778%20444 On 6. avg. 2014, at 22:04, Richard Nute ri...@ieee.orgmailto:ri...@ieee.orgmailto:ri...@ieee.org wrote: Dear Boštjan: If the solar cells are hit by lightning, then the DC and inverter system will likely be destroyed, and the transient will propagate into the AC system. There is no way to protect against a direct lightning strike except to use a system of lightning rods, and they may not provide protection against propagation. Except for a direct lightning strike, no transients appear on the DC side, so OVC does not apply. The 120/240 V AC probably is OVC III, and maybe OVC IV. Since there is no isolation between the AC and the DC, both will see the same AC transients. Your DC side should use the same OVC as the AC side. In my opinion, UL has not fully studied IEC 60664 which is the definitive standard for OVC. UL has extended the OVC requirements to DC without researching the origin and value of transients on DC mains and instead has simply applied the AC OVC to DC mains. According to IEC 60664 and other authorities such as Francois Martzloff, transients on AC systems come from two sources, lightning and load switching. Your solar cell DC source is not subject to load switching, but is subject to a direct lightning strike. Your DC OVC due to load switching is zero, and your OVC due to lightning is beyond OVC IV. Some references: http://www.metrel.si/dl?d=PDF_dokumentacija/White_papers/Ang/White_paper_Overvoltages_and_high_current_breakdowns.pdf http://www.denverpels.org/Downloads/Denver_PELS_20090915_Aldous_Insulation_Coordination.pdf Best regards, Rich On 8/6/2014 11:25 AM, Boštjan Glavič wrote: Dear Rich, Thank you. DC input comes from solar cells therefore from outside. UL 1741 states that OVC IV needs to be used and for 120/240V it means 4000V. So what transient should I use from DC side? Why table 8.1 in UL840 also mentions dc input? Best regards, Bostjan Boštjan Glavič Vodja laboratorija, Laboratorij za elektroniko Head of Laboratory, Laboratory of Electronic Engineering - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.orgmailto:emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@radiusnorth.netmailto:emcp...@radiusnorth.net Mike Cantwell mcantw...@ieee.orgmailto:mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.orgmailto:j.bac...@ieee.org David Heald: dhe...@gmail.commailto:dhe...@gmail.com
Re: [PSES] question with regard of inverter
Dear Boštjan: I participated in most of the drafting of IEC 62368-1. Please feel free to ask questions. So did Pete Perkins. I don't know if others also subscribe to this group. Best regards, Rich On 8/8/2014 7:51 AM, Boštjan Glavič wrote: Dear Rich, dear Doug Thank you very much for your professional answer. I really appreciate it. It helps me a lot and also to my client. One more question, is there any expert in this group who has real experience with new Hazard Based Standard IEC 62368-1? We are currently working on few projects and i think that some requirements are not really clear. Best regards, Bostjan Boštjan Glavič Vodja laboratorija, Laboratorij za elektroniko Head of Laboratory, Laboratory of Electronic Engineering [SIQlogo60px] www.siq.sihttp://www.siq.si/ SIQ Ljubljana, Trzaska c. 2, SI-1000 Ljubljana, Slovenia, VAT ID: SI23509678 t +386 (0)1 4778 265tel:+386%20(0)1%204778%20265, m +386 (0)41 391 283tel:+386%20(0)41%20391%20283, f +386 (0)1 4778 444tel:+386%20(0)1%204778%20444 - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@radiusnorth.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com
Re: [PSES] question with regard of inverter
My understanding as well, namely, OV categorization in power distribution is based on indirect (near-by) lightning strikes. ___ Ralph McDiarmid | Schneider Electric | Solar Business | CANADA | Regulatory Compliance Engineering From: John Woodgate j...@jmwa.demon.co.uk To: EMC-PSTC@LISTSERV.IEEE.ORG, Date: 08/06/2014 01:53 PM Subject: Re: [PSES] question with regard of inverter In message 53e28a32.4020...@ieee.org, dated Wed, 6 Aug 2014, Richard Nute ri...@ieee.org writes: . Your solar cell DC source is not subject to load switching, but is subject to a direct lightning strike. Your DC OVC due to load switching is zero, and your OVC due to lightning is beyond OVC IV. Is resistance to a direct lighting strike required of civilian products? I though that only 'indirect strike' was to be resisted, and OVC IV was based on that. -- OOO - Own Opinions Only. With best wishes. See www.jmwa.demon.co.uk Quid faciamus nisi sit? John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@radiusnorth.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com __ This email has been scanned by the Symantec Email Security.cloud service. __ - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@radiusnorth.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com
Re: [PSES] question with regard of inverter
IEC 62109-1 considers “PV circuits in general” to be OVCII. Regards, Peter Tarver *From:* McDiarmid, Ralph [mailto:ralph.mcdiar...@schneider-electric.com] *Sent:* Friday, August 08, 2014 13:57 *To:* EMC-PSTC@LISTSERV.IEEE.ORG *Subject:* Re: [PSES] question with regard of inverter My understanding as well, namely, OV categorization in power distribution is based on indirect (near-by) lightning strikes. ___ *Ralph McDiarmid* | * Schneider Electric | Solar Business* | *CANADA* | *Regulatory Compliance Engineering* From: John Woodgate j...@jmwa.demon.co.uk To: EMC-PSTC@LISTSERV.IEEE.ORG, Date: 08/06/2014 01:53 PM Subject: Re: [PSES] question with regard of inverter -- In message 53e28a32.4020...@ieee.org, dated Wed, 6 Aug 2014, Richard Nute ri...@ieee.org writes: . Your solar cell DC source is not subject to load switching, but is subject to a direct lightning strike. Your DC OVC due to load switching is zero, and your OVC due to lightning is beyond OVC IV. Is resistance to a direct lighting strike required of civilian products? I though that only 'indirect strike' was to be resisted, and OVC IV was based on that. -- OOO - Own Opinions Only. With best wishes. See www.jmwa.demon.co.uk Quid faciamus nisi sit? John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@radiusnorth.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com __ This email has been scanned by the Symantec Email Security.cloud service. __ - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) http://www.ieee-pses.org/list.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@radiusnorth.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher j.bac...@ieee.org David Heald dhe...@gmail.com This email message is for the sole use of the intended recipient(s) and may contain confidential and/or privileged information. If you are not an intended recipient, you may not review, use, copy, disclose or distribute this message. If you received this message in error, please contact the sender by reply email and destroy all copies of the original message. - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@radiusnorth.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com
Re: [PSES] question with regard of inverter
Peter, All well and good per IEC 62109 however the 800lb gorilla NRTL assessed the PV DC current monitor assembly (a piece of measurment equipment) to be OV CAT IV when it was assessed for certification. The manufacturer grumbled somewhat (since it wasn't designed for that OV category) but agreed that it was probably appropriate, as did I. :) br, Pete Peter E Perkins, PE Principal Product Safety Engineer PO Box 23427 Tigard, ORe 97281-3427 503/452-1201 fone/fax p.perk...@ieee.org From: Peter Tarver [mailto:ptar...@enphaseenergy.com] Sent: Friday, August 08, 2014 3:47 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] question with regard of inverter IEC 62109-1 considers “PV circuits in general” to be OVCII. Regards, Peter Tarver From: McDiarmid, Ralph [mailto:ralph.mcdiar...@schneider-electric.com] Sent: Friday, August 08, 2014 13:57 To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] question with regard of inverter My understanding as well, namely, OV categorization in power distribution is based on indirect (near-by) lightning strikes. ___ Ralph McDiarmid | Schneider Electric | Solar Business | CANADA | Regulatory Compliance Engineering From: John Woodgate j...@jmwa.demon.co.uk To: EMC-PSTC@LISTSERV.IEEE.ORG, Date: 08/06/2014 01:53 PM Subject: Re: [PSES] question with regard of inverter _ In message 53e28a32.4020...@ieee.org, dated Wed, 6 Aug 2014, Richard Nute ri...@ieee.org writes: . Your solar cell DC source is not subject to load switching, but is subject to a direct lightning strike. Your DC OVC due to load switching is zero, and your OVC due to lightning is beyond OVC IV. Is resistance to a direct lighting strike required of civilian products? I though that only 'indirect strike' was to be resisted, and OVC IV was based on that. -- OOO - Own Opinions Only. With best wishes. See www.jmwa.demon.co.uk Quid faciamus nisi sit? John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@radiusnorth.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com __ This email has been scanned by the Symantec Email Security.cloud service. __ - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) http://www.ieee-pses.org/list.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@radiusnorth.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher j.bac...@ieee.org David Heald dhe...@gmail.com This email message is for the sole use of the intended recipient(s) and may contain confidential and/or privileged information. If you are not an intended recipient, you may not review, use, copy, disclose or distribute this message. If you received this message in error, please contact the sender by reply email and destroy all copies of the original message. - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list
[PSES] question with regard of inverter
Dear experts, I am trying to figure out how to determine correct spacings for non-isolated inverter. According UL1741 OVC IV needs to be considered for inverter. From table 8.1 from UL840 I get a transients of 8,0kV for 450VDC input. Is that correct? Output of inverter is connected to AC grid 120/240V. This results in 4kV transients. We have no insulation input/output. Which transient level should I then use? 8kV transient on AC output side is almost impossible for the design. Any idea? Best regards, Bostjan Glavic SIQ - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@radiusnorth.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com
Re: [PSES] question with regard of inverter
Dear Boštjan: Despite UL1741 and UL 840, OVC does not apply to DC. There is no research that I know of that supports use of AC OVC to DC. If the 450 V DC is not outside the building or is otherwise not subject to lightning-caused overvoltages, OVC does not apply. Likewise, if the 450 V DC only supplies a limited number of other loads (which are assumed to generate transients when switched on or off), OVC does not apply. Since there is no isolation from input to output, whatever insulation between input and output is functional insulation. The transients that appear on the AC output side (generated by load switching and lightning) will also appear on the DC side. 120\240 V overvoltages are OVC II and are 3 kV according to IEC 60664, not 4 kV. Best regards, Rich On 8/6/2014 10:39 AM, Boštjan Glavič wrote: Dear experts, I am trying to figure out how to determine correct spacings for non-isolated inverter. According UL1741 OVC IV needs to be considered for inverter. From table 8.1 from UL840 I get a transients of 8,0kV for 450VDC input. Is that correct? Output of inverter is connected to AC grid 120/240V. This results in 4kV transients. We have no insulation input/output. Which transient level should I then use? 8kV transient on AC output side is almost impossible for the design. Any idea? Best regards, Bostjan Glavic SIQ - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org mailto:emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@radiusnorth.net mailto:emcp...@radiusnorth.net Mike Cantwell mcantw...@ieee.org mailto:mcantw...@ieee.org For policy questions, send mail to: Jim Bacher j.bac...@ieee.org mailto:j.bac...@ieee.org David Heald dhe...@gmail.com mailto:dhe...@gmail.com - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@radiusnorth.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com
Re: [PSES] question with regard of inverter
Dear Rich, Thank you. DC input comes from solar cells therefore from outside. UL 1741 states that OVC IV needs to be used and for 120/240V it means 4000V. So what transient should I use from DC side? Why table 8.1 in UL840 also mentions dc input? Best regards, Bostjan Boštjan Glavič Vodja laboratorija, Laboratorij za elektroniko Head of Laboratory, Laboratory of Electronic Engineering [SIQlogo60px] www.siq.sihttp://www.siq.si/ SIQ Ljubljana, Trzaska c. 2, SI-1000 Ljubljana, Slovenia, VAT ID: SI23509678 t +386 (0)1 4778 265tel:+386%20(0)1%204778%20265, m +386 (0)41 391 283tel:+386%20(0)41%20391%20283, f +386 (0)1 4778 444tel:+386%20(0)1%204778%20444 On 6. avg. 2014, at 20:17, Richard Nute ri...@ieee.orgmailto:ri...@ieee.org wrote: Dear Boštjan: Despite UL1741 and UL 840, OVC does not apply to DC. There is no research that I know of that supports use of AC OVC to DC. If the 450 V DC is not outside the building or is otherwise not subject to lightning-caused overvoltages, OVC does not apply. Likewise, if the 450 V DC only supplies a limited number of other loads (which are assumed to generate transients when switched on or off), OVC does not apply. Since there is no isolation from input to output, whatever insulation between input and output is functional insulation. The transients that appear on the AC output side (generated by load switching and lightning) will also appear on the DC side. 120\240 V overvoltages are OVC II and are 3 kV according to IEC 60664, not 4 kV. Best regards, Rich On 8/6/2014 10:39 AM, Boštjan Glavič wrote: Dear experts, I am trying to figure out how to determine correct spacings for non-isolated inverter. According UL1741 OVC IV needs to be considered for inverter. From table 8.1 from UL840 I get a transients of 8,0kV for 450VDC input. Is that correct? Output of inverter is connected to AC grid 120/240V. This results in 4kV transients. We have no insulation input/output. Which transient level should I then use? 8kV transient on AC output side is almost impossible for the design. Any idea? Best regards, Bostjan Glavic SIQ - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.orgmailto:emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe)http://www.ieee-pses.org/list.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@radiusnorth.netmailto:emcp...@radiusnorth.net Mike Cantwell mcantw...@ieee.orgmailto:mcantw...@ieee.org For policy questions, send mail to: Jim Bacher j.bac...@ieee.orgmailto:j.bac...@ieee.org David Heald dhe...@gmail.commailto:dhe...@gmail.com - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@radiusnorth.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com
Re: [PSES] question with regard of inverter
Bostjan, Even though PV array can be subject to lightning strikes, to my knowledge there is no specific requirement for OV transients occurring on the DC side of your inverter. This leaves you in a bit of a quandary fro spacings determination on the DC side, especially if you have no transformer isolation. Although your power production is from DC to AC, your system is still subjected to OV transients originating from the AC side mains connections. These connections will indeed be category IV if you are connected to the LV side of an MV transformer. For the DC side, I would use the Controlled Overvoltage requirements in of UL 840 for the DC side (see Clause 8.7). Depending on the design of your product and the likelihood of AC side transients propagating through to the DC side, you may be able to reduce the OV Cat by one full step or more on the DC side. This can be achieved in a few ways, transformer isolation being the most obvious. However, the standard does allow attenuation by impedance networks. In this case the impedance network is comprised of your AC EMI filter, AC line reactors, and DC bus cap. Approved transient suppression devices can also be useful. If you believe your system is able to absorb or suppress these transients to a level below Cat IV by virtue of the impedance network, you can prove this is true through test by applying OV Cat IV impulses the mains and monitoring the circuit in question using an oscope (UL 840 section 12.1). In this case use the 1.25/50 uS impulse test. Be certain your application of the impulses and the connection of you oscope is in all orientations of line to line and line to earth, in order to see the maximum impulses available on the DC side. Your results should not exceed OV Cat III, for example. Good luck, –doug Douglas E Powell http://www.linkedin.com/in/dougp01 On Wed, Aug 6, 2014 at 12:25 PM, Boštjan Glavič bostjan.gla...@siq.si wrote: Dear Rich, Thank you. DC input comes from solar cells therefore from outside. UL 1741 states that OVC IV needs to be used and for 120/240V it means 4000V. So what transient should I use from DC side? Why table 8.1 in UL840 also mentions dc input? Best regards, Bostjan Boštjan Glavič Vodja laboratorija, Laboratorij za elektroniko Head of Laboratory, Laboratory of Electronic Engineering [SIQlogo60px] www.siq.sihttp://www.siq.si/ SIQ Ljubljana, Trzaska c. 2, SI-1000 Ljubljana, Slovenia, VAT ID: SI23509678 t +386 (0)1 4778 265tel:+386%20(0)1%204778%20265, m +386 (0)41 391 283tel:+386%20(0)41%20391%20283, f +386 (0)1 4778 444tel:+386%20(0)1%204778%20444 On 6. avg. 2014, at 20:17, Richard Nute ri...@ieee.orgmailto: ri...@ieee.org wrote: Dear Boštjan: Despite UL1741 and UL 840, OVC does not apply to DC. There is no research that I know of that supports use of AC OVC to DC. If the 450 V DC is not outside the building or is otherwise not subject to lightning-caused overvoltages, OVC does not apply. Likewise, if the 450 V DC only supplies a limited number of other loads (which are assumed to generate transients when switched on or off), OVC does not apply. Since there is no isolation from input to output, whatever insulation between input and output is functional insulation. The transients that appear on the AC output side (generated by load switching and lightning) will also appear on the DC side. 120\240 V overvoltages are OVC II and are 3 kV according to IEC 60664, not 4 kV. Best regards, Rich On 8/6/2014 10:39 AM, Boštjan Glavič wrote: Dear experts, I am trying to figure out how to determine correct spacings for non-isolated inverter. According UL1741 OVC IV needs to be considered for inverter. From table 8.1 from UL840 I get a transients of 8,0kV for 450VDC input. Is that correct? Output of inverter is connected to AC grid 120/240V. This results in 4kV transients. We have no insulation input/output. Which transient level should I then use? 8kV transient on AC output side is almost impossible for the design. Any idea? Best regards, Bostjan Glavic SIQ - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.orgmailto:emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe)http://www.ieee-pses.org/list.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@radiusnorth.netmailto:emcp...@radiusnorth.net Mike Cantwell
Re: [PSES] question with regard of inverter
Dear Boštjan: If the solar cells are hit by lightning, then the DC and inverter system will likely be destroyed, and the transient will propagate into the AC system. There is no way to protect against a direct lightning strike except to use a system of lightning rods, and they may not provide protection against propagation. Except for a direct lightning strike, no transients appear on the DC side, so OVC does not apply. The 120/240 V AC probably is OVC III, and maybe OVC IV. Since there is no isolation between the AC and the DC, both will see the same AC transients. Your DC side should use the same OVC as the AC side. In my opinion, UL has not fully studied IEC 60664 which is the definitive standard for OVC. UL has extended the OVC requirements to DC without researching the origin and value of transients on DC mains and instead has simply applied the AC OVC to DC mains. According to IEC 60664 and other authorities such as Francois Martzloff, transients on AC systems come from two sources, lightning and load switching. Your solar cell DC source is not subject to load switching, but is subject to a direct lightning strike. Your DC OVC due to load switching is zero, and your OVC due to lightning is beyond OVC IV. Some references: http://www.metrel.si/dl?d=PDF_dokumentacija/White_papers/Ang/White_paper_Overvoltages_and_high_current_breakdowns.pdf http://www.denverpels.org/Downloads/Denver_PELS_20090915_Aldous_Insulation_Coordination.pdf Best regards, Rich On 8/6/2014 11:25 AM, Boštjan Glavič wrote: Dear Rich, Thank you. DC input comes from solar cells therefore from outside. UL 1741 states that OVC IV needs to be used and for 120/240V it means 4000V. So what transient should I use from DC side? Why table 8.1 in UL840 also mentions dc input? Best regards, Bostjan Boštjan Glavič Vodja laboratorija, Laboratorij za elektroniko Head of Laboratory, Laboratory of Electronic Engineering - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@radiusnorth.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com
Re: [PSES] question with regard of inverter
In message 53e28a32.4020...@ieee.org, dated Wed, 6 Aug 2014, Richard Nute ri...@ieee.org writes: . Your solar cell DC source is not subject to load switching, but is subject to a direct lightning strike. Your DC OVC due to load switching is zero, and your OVC due to lightning is beyond OVC IV. Is resistance to a direct lighting strike required of civilian products? I though that only 'indirect strike' was to be resisted, and OVC IV was based on that. -- OOO - Own Opinions Only. With best wishes. See www.jmwa.demon.co.uk Quid faciamus nisi sit? John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@radiusnorth.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com
