Re: [PSES] VTM-2 Rated Film - Proper Electrical Barrier
http://style.org/strouhalflight/ Have also used Strouhal number to calc air flow in non-circular plenum. Physics works. Brian -Original Message- From: emc-p...@ieee.org [mailto:emc-p...@ieee.org]On Behalf Of Wiseman, Joshua E Sent: Wednesday, November 14, 2012 1:57 PM To: Kunde, Brian; EMC-PSTC@LISTSERV.IEEE.ORG Subject: RE: [PSES] VTM-2 Rated Film - Proper Electrical Barrier Is that an European or African swallow? Josh -Original Message- From: Kunde, Brian [mailto:brian_ku...@lecotc.com] Sent: Wednesday, November 14, 2012 2:41 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] VTM-2 Rated Film - Proper Electrical Barrier Yes, but what is the airspeed of an unladen swallow? The Other Brian -Original Message- From: emc-p...@ieee.org [mailto:emc-p...@ieee.org] On Behalf Of Brian Oconnell Sent: Wednesday, November 14, 2012 3:30 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: RE: [PSES] VTM-2 Rated Film - Proper Electrical Barrier Excellent point. And it (not the elderberry smell) was used at a PSES symposium session as one of the reasons to fire the conformity assessment body. There may be a time when the assessor is intractable and will offer only vague hand waves in lieu of any rationale. But first talk to a technical authority at the agency to verify that the requirement is capricious. "Your mother was a hamster and your father smelt of elderberries." -- Monty Python and the Holy Grail Brian -Original Message- From: emc-p...@ieee.org [mailto:emc-p...@ieee.org]On Behalf Of Peter Tarver Sent: Wednesday, November 14, 2012 12:02 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: RE: [PSES] VTM-2 Rated Film - Proper Electrical Barrier > From: Brian Oconnell > Sent: Tuesday, November 13, 2012 15:28 > > OHSA allows the recognized lab use of 'engineering judgment' and > reference to corporate policy for acceptance or rejection of > construction. And various instances of adjudication have allowed > internal lab 'policy' that would be in addition to, or in lieu of, a > normative reference from an ANSI safety standard. None of this effects the need for explanation, even if it's, "you're father smells of elderberries." There has to be a rationale even for a policy. Denial of sound engineering rationale casts a pall on the reputation of an NRTL and would be reason to move on. If the product is not intended exclusively for the workplace, OSHA's opinion is of no account. During prior employment, I applied similar to the stated OSHA position to a coffee percolator. The device would not heat up enough to allow normal operation (or to even warm water). The customer was told that the certification service would not be forthcoming, but I had to explain why. Whether it's considered a matter of fairness or a response to contracted services, some explanation is needed. Peter Tarver - 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 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://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas Mike Cantwell For policy questions, send mail to: Jim Bacher: David Heald: LECO Corporation Notice: This communication may contain confidential information intended for the named recipient(s) only. If you received this by mistake, please destroy it and notify us of the error. Thank you. - 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 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://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas Mike Cantwell For policy questions, send mail to: Jim Bacher: David Heald: - 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 t
Re: [PSES] VTM-2 Rated Film - Proper Electrical Barrier
Is that an European or African swallow? Josh -Original Message- From: Kunde, Brian [mailto:brian_ku...@lecotc.com] Sent: Wednesday, November 14, 2012 2:41 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] VTM-2 Rated Film - Proper Electrical Barrier Yes, but what is the airspeed of an unladen swallow? The Other Brian -Original Message- From: emc-p...@ieee.org [mailto:emc-p...@ieee.org] On Behalf Of Brian Oconnell Sent: Wednesday, November 14, 2012 3:30 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: RE: [PSES] VTM-2 Rated Film - Proper Electrical Barrier Excellent point. And it (not the elderberry smell) was used at a PSES symposium session as one of the reasons to fire the conformity assessment body. There may be a time when the assessor is intractable and will offer only vague hand waves in lieu of any rationale. But first talk to a technical authority at the agency to verify that the requirement is capricious. "Your mother was a hamster and your father smelt of elderberries." -- Monty Python and the Holy Grail Brian -Original Message- From: emc-p...@ieee.org [mailto:emc-p...@ieee.org]On Behalf Of Peter Tarver Sent: Wednesday, November 14, 2012 12:02 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: RE: [PSES] VTM-2 Rated Film - Proper Electrical Barrier > From: Brian Oconnell > Sent: Tuesday, November 13, 2012 15:28 > > OHSA allows the recognized lab use of 'engineering judgment' and > reference to corporate policy for acceptance or rejection of > construction. And various instances of adjudication have allowed > internal lab 'policy' that would be in addition to, or in lieu of, a > normative reference from an ANSI safety standard. None of this effects the need for explanation, even if it's, "you're father smells of elderberries." There has to be a rationale even for a policy. Denial of sound engineering rationale casts a pall on the reputation of an NRTL and would be reason to move on. If the product is not intended exclusively for the workplace, OSHA's opinion is of no account. During prior employment, I applied similar to the stated OSHA position to a coffee percolator. The device would not heat up enough to allow normal operation (or to even warm water). The customer was told that the certification service would not be forthcoming, but I had to explain why. Whether it's considered a matter of fairness or a response to contracted services, some explanation is needed. Peter Tarver - 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 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://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas Mike Cantwell For policy questions, send mail to: Jim Bacher: David Heald: LECO Corporation Notice: This communication may contain confidential information intended for the named recipient(s) only. If you received this by mistake, please destroy it and notify us of the error. Thank you. - 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 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://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas Mike Cantwell For policy questions, send mail to: Jim Bacher: David Heald: - 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 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://listserv.ieee.org/r
Re: [PSES] VTM-2 Rated Film - Proper Electrical Barrier
Yes, but what is the airspeed of an unladen swallow? The Other Brian -Original Message- From: emc-p...@ieee.org [mailto:emc-p...@ieee.org] On Behalf Of Brian Oconnell Sent: Wednesday, November 14, 2012 3:30 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: RE: [PSES] VTM-2 Rated Film - Proper Electrical Barrier Excellent point. And it (not the elderberry smell) was used at a PSES symposium session as one of the reasons to fire the conformity assessment body. There may be a time when the assessor is intractable and will offer only vague hand waves in lieu of any rationale. But first talk to a technical authority at the agency to verify that the requirement is capricious. "Your mother was a hamster and your father smelt of elderberries." -- Monty Python and the Holy Grail Brian -Original Message- From: emc-p...@ieee.org [mailto:emc-p...@ieee.org]On Behalf Of Peter Tarver Sent: Wednesday, November 14, 2012 12:02 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: RE: [PSES] VTM-2 Rated Film - Proper Electrical Barrier > From: Brian Oconnell > Sent: Tuesday, November 13, 2012 15:28 > > OHSA allows the recognized lab use of 'engineering judgment' and > reference to corporate policy for acceptance or rejection of > construction. And various instances of adjudication have allowed > internal lab 'policy' that would be in addition to, or in lieu of, a > normative reference from an ANSI safety standard. None of this effects the need for explanation, even if it's, "you're father smells of elderberries." There has to be a rationale even for a policy. Denial of sound engineering rationale casts a pall on the reputation of an NRTL and would be reason to move on. If the product is not intended exclusively for the workplace, OSHA's opinion is of no account. During prior employment, I applied similar to the stated OSHA position to a coffee percolator. The device would not heat up enough to allow normal operation (or to even warm water). The customer was told that the certification service would not be forthcoming, but I had to explain why. Whether it's considered a matter of fairness or a response to contracted services, some explanation is needed. Peter Tarver - 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 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://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas Mike Cantwell For policy questions, send mail to: Jim Bacher: David Heald: LECO Corporation Notice: This communication may contain confidential information intended for the named recipient(s) only. If you received this by mistake, please destroy it and notify us of the error. Thank you. - 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 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://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas Mike Cantwell For policy questions, send mail to: Jim Bacher: David Heald:
Re: [PSES] VTM-2 Rated Film - Proper Electrical Barrier
Excellent point. And it (not the elderberry smell) was used at a PSES symposium session as one of the reasons to fire the conformity assessment body. There may be a time when the assessor is intractable and will offer only vague hand waves in lieu of any rationale. But first talk to a technical authority at the agency to verify that the requirement is capricious. "Your mother was a hamster and your father smelt of elderberries." -- Monty Python and the Holy Grail Brian -Original Message- From: emc-p...@ieee.org [mailto:emc-p...@ieee.org]On Behalf Of Peter Tarver Sent: Wednesday, November 14, 2012 12:02 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: RE: [PSES] VTM-2 Rated Film - Proper Electrical Barrier > From: Brian Oconnell > Sent: Tuesday, November 13, 2012 15:28 > > OHSA allows the recognized lab use of 'engineering > judgment' and reference to corporate policy for > acceptance or rejection of construction. And various > instances of adjudication have allowed internal lab > 'policy' that would be in addition to, or in lieu of, a > normative reference from an ANSI safety standard. None of this effects the need for explanation, even if it's, "you're father smells of elderberries." There has to be a rationale even for a policy. Denial of sound engineering rationale casts a pall on the reputation of an NRTL and would be reason to move on. If the product is not intended exclusively for the workplace, OSHA's opinion is of no account. During prior employment, I applied similar to the stated OSHA position to a coffee percolator. The device would not heat up enough to allow normal operation (or to even warm water). The customer was told that the certification service would not be forthcoming, but I had to explain why. Whether it's considered a matter of fairness or a response to contracted services, some explanation is needed. Peter Tarver - 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 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://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas Mike Cantwell For policy questions, send mail to: Jim Bacher: David Heald:
Re: [PSES] VTM-2 Rated Film - Proper Electrical Barrier
> From: Brian Oconnell > Sent: Tuesday, November 13, 2012 15:28 > > OHSA allows the recognized lab use of 'engineering > judgment' and reference to corporate policy for > acceptance or rejection of construction. And various > instances of adjudication have allowed internal lab > 'policy' that would be in addition to, or in lieu of, a > normative reference from an ANSI safety standard. None of this effects the need for explanation, even if it's, "you're father smells of elderberries." There has to be a rationale even for a policy. Denial of sound engineering rationale casts a pall on the reputation of an NRTL and would be reason to move on. If the product is not intended exclusively for the workplace, OSHA's opinion is of no account. During prior employment, I applied similar to the stated OSHA position to a coffee percolator. The device would not heat up enough to allow normal operation (or to even warm water). The customer was told that the certification service would not be forthcoming, but I had to explain why. Whether it's considered a matter of fairness or a response to contracted services, some explanation is needed. Peter Tarver 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 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://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas Mike Cantwell For policy questions, send mail to: Jim Bacher: David Heald:
Re: [PSES] VTM-2 Rated Film - Proper Electrical Barrier
Hello Brian and Group, As a follow-up to my original posting a couple of weeks ago, the agency has backed down and agreed to accept the VTM-2 film as submitted. Thanks to all who provided comment. Good evening, Richard Pittenger Hobart From: Brian Oconnell [oconne...@tamuracorp.com] Sent: Tuesday, November 13, 2012 6:27 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] VTM-2 Rated Film - Proper Electrical Barrier "In either case, the NRTL owes you an engineering rationale for their claim of noncompliance. Because Mama said so doesn’t fly." OHSA allows the recognized lab use of 'engineering judgment' and reference to corporate policy for acceptance or rejection of construction. And various instances of adjudication have allowed internal lab 'policy' that would be in addition to, or in lieu of, a normative reference from an ANSI safety standard. Brian - 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 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://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas Mike Cantwell For policy questions, send mail to: Jim Bacher: David Heald: Disclaimer - This email and any files transmitted with it are confidential and contain privileged or copyrighted information. You must not present this message to another party without first gaining permission from the sender. If you are not the intended recipient, you must not copy, print, distribute or use this email or the information contained in it for any purpose other than to notify us. If you received this email in error, please notify the sender immediately and delete this email from your system. We do not guarantee that this email is free from viruses or any other defects although due care has been taken to minimize the risk. - 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 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://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas Mike Cantwell For policy questions, send mail to: Jim Bacher: David Heald:
Re: [PSES] VTM-2 Rated Film - Proper Electrical Barrier
"In either case, the NRTL owes you an engineering rationale for their claim of noncompliance. Because Mama said so doesn’t fly." OHSA allows the recognized lab use of 'engineering judgment' and reference to corporate policy for acceptance or rejection of construction. And various instances of adjudication have allowed internal lab 'policy' that would be in addition to, or in lieu of, a normative reference from an ANSI safety standard. Brian - 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 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://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas Mike Cantwell For policy questions, send mail to: Jim Bacher: David Heald:
Re: [PSES] VTM-2 Rated Film - Proper Electrical Barrier
Richard – I’ve run into similar issues with NRTLs before. Much depends on the standard being applied. If UL 746C is being applied (by reference from the end-product standard), Table 6.1 outlines the requirements for a barrier or liner and the flame rating will determine some of the other material properties that apply (insulator requirements are independent of flame rating). There’s also a gotcha in UL 746C that a barrier or liner needs to be ≥ 0.71 mm thick to ignore a clearance altogether, or as thin as 0.33 mm to halve the otherwise required clearance. Thinner materials require a “separate evaluation.” This might be where your issue lies. On the other hand, if UL 746C is not being used, the requirements fall out from the end-product standard. In either case, the NRTL owes you an engineering rationale for their claim of noncompliance. Because Mama said so doesn’t fly. Peter Tarver *From:* Richard Pittenger [mailto:richard.pitten...@hobartcorp.com] *Sent:* Friday, November 02, 2012 11:21 Esteemed Colleagues, I have a product submitted to NRTL “E” that uses a Mylar electrical barrier between line-voltage (120 V ac), uninsulated live parts on a circuit board and the aluminum electrical enclosure. The ‘through-air’ spacing would be a little short without this barrier in place. The barrier material has a UL 94 VTM-2 flame rating and has been accepted in other similar products for many years in similar applications by NRTL “U”. NRTL “E” is objecting to use of this material for this application but so far has not provided a reason. Can any of you think of a reason why a plastic film with a VTM-2 flame rating shouldn’t be used as an electrical barrier? 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 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://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas Mike Cantwell For policy questions, send mail to: Jim Bacher: David Heald:
Re: [PSES] VTM-2 Rated Film - Proper Electrical Barrier
Hi Richard: Unfortunately, this situation mixes two, independent requirements: 1) electrical insulation requirements, and 2) anti-fire requirements. If the clearance (air insulation) is insufficient for basic insulation, then a solid insulation may be used in place of the clearance. If the metal enclosure is grounded, then the insulation must be basic insulation, and no requirements for the thickness of the solid insulation. If the metal enclosure is not grounded, then the solid insulation comprises supplementary insulation and must be at least 0.4 mm thick. (Typically, no other electrical properties apply to the solid insulation.) Without knowing anything further about the construction, the material will need to be rated at least HB for anti-fire. The applicable standard will specify the required flammability rating. In some cases, all material within the power supply must be at least V2 (equivalently VTM2). Don’t let the certification house mix up the two requirements. As others have advised, insist the cert house show you the written requirements! Best regards, Rich -Original Message- From: Richard Pittenger Sent: Friday, November 02, 2012 11:21 AM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: VTM-2 Rated Film - Proper Electrical Barrier Esteemed Colleagues, I have a product submitted to NRTL “E” that uses a Mylar electrical barrier between line-voltage (120 V ac), uninsulated live parts on a circuit board and the aluminum electrical enclosure. The ‘through-air’ spacing would be a little short without this barrier in place. The barrier material has a UL 94 VTM-2 flame rating and has been accepted in other similar products for many years in similar applications by NRTL “U”. NRTL “E” is objecting to use of this material for this application but so far has not provided a reason. Can any of you think of a reason why a plastic film with a VTM-2 flame rating shouldn’t be used as an electrical barrier? Thanks for any and all comments. Regards, Richard Pittenger Agency Approval Engineer Food Machines Engineering Hobart/Berkel - 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 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://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas Mike Cantwell For policy questions, send mail to: Jim Bacher: David Heald:
Re: [PSES] VTM-2 Rated Film - Proper Electrical Barrier
And some standards will provide only a reduction in clearance if an insulator is used, it won't necessarily replace the need for a clearance. (as silly as that may sound) ___ Ralph McDiarmid | Schneider Electric | Solar Business | CANADA | Regulatory Compliance Engineering From: "jral...@productsafetyinc.com" To: EMC-PSTC@LISTSERV.IEEE.ORG, Date: 11/02/2012 12:54 PM Subject: Re: [PSES] VTM-2 Rated Film - Proper Electrical Barrier Flame rating doesn’t mean it’s an insulator. Is it an insulator? What are the Dielectric properties? Insulators depend on the Standard. Most I’ve worked in require insulators to be 0.7mm thick, minimum. They also may be concerned that a sharp solder point or component pins can pierce the insulation. We’ve used mica and fish paper without issues. Also, the orange insulator (Kapton) I think is either GE or EI Dupont and we’ve used it many times in the past. For NRTL E – make him point to the clause in the Standard From: Richard Pittenger [mailto:richard.pitten...@hobartcorp.com] Sent: Friday, November 02, 2012 1:21 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: [PSES] VTM-2 Rated Film - Proper Electrical Barrier Esteemed Colleagues, I have a product submitted to NRTL “E” that uses a Mylar electrical barrier between line-voltage (120 V ac), uninsulated live parts on a circuit board and the aluminum electrical enclosure. The ‘through-air’ spacing would be a little short without this barrier in place. The barrier material has a UL 94 VTM-2 flame rating and has been accepted in other similar products for many years in similar applications by NRTL “U”. NRTL “E” is objecting to use of this material for this application but so far has not provided a reason. Can any of you think of a reason why a plastic film with a VTM-2 flame rating shouldn’t be used as an electrical barrier? Thanks for any and all comments. Regards, Richard Pittenger Agency Approval Engineer Food Machines Engineering Hobart/Berkel Disclaimer - This email and any files transmitted with it are confidential and contain privileged or copyrighted information. You must not present this message to another party without first gaining permission from the sender. If you are not the intended recipient, you must not copy, print, distribute or use this email or the information contained in it for any purpose other than to notify us. If you received this email in error, please notify the sender immediately and delete this email from your system. We do not guarantee that this email is free from viruses or any other defects although due care has been taken to minimize the risk. - 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://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas Mike Cantwell For policy questions, send mail to: Jim Bacher David Heald __ 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://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas Mike Cantwell For policy questions, send mail to: Jim Bacher David Heald - 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 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 Onlin
Re: [PSES] VTM-2 Rated Film - Proper Electrical Barrier
Flame rating doesn't mean it's an insulator. Is it an insulator? What are the Dielectric properties? Insulators depend on the Standard. Most I've worked in require insulators to be 0.7mm thick, minimum. They also may be concerned that a sharp solder point or component pins can pierce the insulation. We've used mica and fish paper without issues. Also, the orange insulator (Kapton) I think is either GE or EI Dupont and we've used it many times in the past. For NRTL E - make him point to the clause in the Standard From: Richard Pittenger [mailto:richard.pitten...@hobartcorp.com] Sent: Friday, November 02, 2012 1:21 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: [PSES] VTM-2 Rated Film - Proper Electrical Barrier Esteemed Colleagues, I have a product submitted to NRTL "E" that uses a Mylar electrical barrier between line-voltage (120 V ac), uninsulated live parts on a circuit board and the aluminum electrical enclosure. The 'through-air' spacing would be a little short without this barrier in place. The barrier material has a UL 94 VTM-2 flame rating and has been accepted in other similar products for many years in similar applications by NRTL "U". NRTL "E" is objecting to use of this material for this application but so far has not provided a reason. Can any of you think of a reason why a plastic film with a VTM-2 flame rating shouldn't be used as an electrical barrier? Thanks for any and all comments. Regards, Richard Pittenger Agency Approval Engineer Food Machines Engineering Hobart/Berkel Disclaimer - This email and any files transmitted with it are confidential and contain privileged or copyrighted information. You must not present this message to another party without first gaining permission from the sender. If you are not the intended recipient, you must not copy, print, distribute or use this email or the information contained in it for any purpose other than to notify us. If you received this email in error, please notify the sender immediately and delete this email from your system. We do not guarantee that this email is free from viruses or any other defects although due care has been taken to minimize the risk. - 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 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://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas mailto:emcp...@radiusnorth.net>> Mike Cantwell mailto:mcantw...@ieee.org>> For policy questions, send mail to: Jim Bacher mailto:j.bac...@ieee.org>> David Heald 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 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://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas Mike Cantwell For policy questions, send mail to: Jim Bacher: David Heald:
Re: [PSES] VTM-2 Rated Film - Proper Electrical Barrier
In message <99280a01673ff44180f15babb58896ca091b2ae...@troyex2.itwfeg.biz>, dated Fri, 2 Nov 2012, Richard Pittenger writes: NRTL ?E? is objecting to use of this material for this application but so far has not provided a reason. Can any of you think of a reason why a plastic film with a VTM-2 flame rating shouldn?t be used as an electrical barrier? Surely it's up to the NRTL to say why they object. It might be because the part could be removed during servicing and not replaced. -- OOO - Own Opinions Only. See www.jmwa.demon.co.uk The longer it takes to make a point, the more obtuse it proves to be. 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 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://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas Mike Cantwell For policy questions, send mail to: Jim Bacher: David Heald:
Re: [PSES] VTM-2 Rated Film - Proper Electrical Barrier
The NRTL assessment engineer must provide specific requirements via normative clauses of the scoped standard, or a formal corporate policy that has been published. If this person will not or cannot, immediately contact the agency's technical authority for the scope of your equipment. The OSHA NRTL program does allow a certain latitude per 'engineering judgment'. The material shall be rated for your intended use and conditions of acceptability. Creepage and Clearance are defined and specified in all ANSI safety standards. I will address these type of agency issues at the PSES symposium. Brian -Original Message- From: emc-p...@ieee.org [mailto:emc-p...@ieee.org]On Behalf Of Richard Pittenger Sent: Friday, November 02, 2012 11:21 AM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: VTM-2 Rated Film - Proper Electrical Barrier Esteemed Colleagues, I have a product submitted to NRTL "E" that uses a Mylar electrical barrier between line-voltage (120 V ac), uninsulated live parts on a circuit board and the aluminum electrical enclosure. The 'through-air' spacing would be a little short without this barrier in place. The barrier material has a UL 94 VTM-2 flame rating and has been accepted in other similar products for many years in similar applications by NRTL "U". NRTL "E" is objecting to use of this material for this application but so far has not provided a reason. Can any of you think of a reason why a plastic film with a VTM-2 flame rating shouldn't be used as an electrical barrier? Thanks for any and all comments. Regards, Richard Pittenger Agency Approval Engineer Food Machines Engineering Hobart/Berkel Disclaimer - This email and any files transmitted with it are confidential and contain privileged or copyrighted information. You must not present this message to another party without first gaining permission from the sender. If you are not the intended recipient, you must not copy, print, distribute or use this email or the information contained in it for any purpose other than to notify us. If you received this email in error, please notify the sender immediately and delete this email from your system. We do not guarantee that this email is free from viruses or any other defects although due care has been taken to minimize the risk. - 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 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://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas Mike Cantwell For policy questions, send mail to: Jim Bacher David Heald - 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 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://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas Mike Cantwell For policy questions, send mail to: Jim Bacher: David Heald:
