RE: Switching Transformer Safety Standards
My apologies, but I meant 61010-1, the end product standard. (My fingers can sometimes type faster than my brain can work.) Ted Eckert Compliance Engineer Microsoft Corporation ted.eck...@microsoft.com The opinions expressed are my own and do not necessarily reflect those of my employer. From: peter merguerian [mailto:pmerguerian2...@yahoo.com] Sent: Wednesday, January 28, 2009 8:47 PM To: Kunde, Brian; EMC-PSTC@LISTSERV.IEEE.ORG; Ted Eckert Subject: RE: Switching Transformer Safety Standards Brian, I agree with Ted, but replace the standard with IEC/EN/UL 61010-1 (your end product standard). There is no reason to abide by other standards unless the 61010-1 standard refers to another standard. Best Regards, Peter --- On Wed, 1/28/09, Ted Eckert wrote: From: Ted Eckert Subject: RE: Switching Transformer Safety Standards To: "Kunde, Brian" , "EMC-PSTC@LISTSERV.IEEE.ORG" Date: Wednesday, January 28, 2009, 3:07 PM Hello Brian, These are some general guidelines and are not necessarily complete. You should be able to have the transformer evaluated under 60601 as part of your product. You will need to obey all of the creepage, clearance and insulation thickness requirements of 60601. You will also need to consider any required electric strength test from primary to secondary. Additionally, consider the maximum temperature expected when selecting your insulation materials. How you construct the transformer will depend on the type of bobbin you intend to use. I presume the bobbin selection will be based on a trade-off of cost, size and efficiency. If the transformer can be large an inefficient, the safety will likely be easier to manage. I realize that a lot of what I stated may be obvious, but it covers a lot of the basics of switch-mode transformer safety. The devil is in the details. Verifying all of the required parameters on a small transformer can be difficult as there can be many creepage paths. With a 2 kW output power, I presume that this wonʼt be a small transformer. Ted Eckert Compliance Engineer Microsoft Corporation ted.eck...@microsoft.com The opinions expressed are my own and do not necessarily reflect those of my employer. From: Kunde, Brian [mailto:brian_ku...@lecotc.com] Sent: Wednesday, January 28, 2009 2:01 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Switching Transformer Safety Standards Greetings Transformer Experts, We need to design a custom switching transformer that runs at 25kHz, modulated 230VAC mains input and 4kVrms (.5A) output as part of a 4KV HV power supply. We want to design and test this transformer properly for safety so can anyone give us a list of construction and/or safety standards to cover UL, CSA, Europe and any international IEC requirements? We are not experts in the world of specialty transformer safety and usually rely on the manufacture for construction information but in this case we would like to get more involved with the details and knowing what standards to design to would be very helpful. The end product will be used in a piece of laboratory equipment. (61010-1). Thank you and best regards, The Other Brian _ 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 mailto:emc-p...@ieee.org> > All emc-pstc postings are archived and searchable on the web at http://www.ieeecommunities.org/emc-pstc <http://www.ieeecommunities.org/emc-pstc> Graphics (in well-used formats), large files, etc. can be posted to that URL. Website: http://www.ieee-pses.org/ <http://www.ieee-pses.org/> Instructions: http://listserv.ieee.org/request/user-guide.html <http://listserv.ieee.org/request/user-guide.html> 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 mailto:emcp...@ptcnh.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 mailto:emc-p...@ieee.org> > All emc-pstc postings are archived and searchable on the web at http://www.ieeecommunities.org/emc-pstc <http://www.ieeecommunities.org/emc-pstc> Graphics (in well-used formats), large files, etc. can be posted to that URL. Website: http://www.ieee-pses.org/ <h
RE: Switching Transformer Safety Standards
Brian,
I agree with Ted, but replace the standard with IEC/EN/UL 61010-1 (your end
product standard). There is no reason to abide by other standards unless the
61010-1 standard refers to another standard.
Best Regards,
Peter
--- On Wed, 1/28/09, Ted Eckert wrote:
From: Ted Eckert
Subject: RE: Switching Transformer Safety Standards
To: "Kunde, Brian" ,
"EMC-PSTC@LISTSERV.IEEE.ORG"
Date: Wednesday, January 28, 2009, 3:07 PM
Hello Brian,
These are some general guidelines and are not necessarily complete.
You should be able to have the transformer evaluated under 60601 as
part of
your product. You will need to obey all of the creepage, clearance and
insulation thickness requirements of 60601. You will also need to consider
any required electric strength test from primary to secondary. Additionally,
consider the maximum temperature expected when selecting your insulation
materials.
How you construct the transformer will depend on the type of bobbin you
intend to use. I presume the bobbin selection will be based on a trade-off of
cost, size and efficiency. If the transformer can be large an inefficient,
the safety will likely be easier to manage.
I realize that a lot of what I stated may be obvious, but it covers a
lot of
the basics of switch-mode transformer safety. The devil is in the details.
Verifying all of the required parameters on a small transformer can be
difficult as there can be many creepage paths. With a 2 kW output power, I
presume that this won¢t be a small transformer.
Ted Eckert
Compliance Engineer
Microsoft Corporation
ted.eck...@microsoft.com
The opinions expressed are my own and do not necessarily reflect those
of my
employer.
From: Kunde, Brian [mailto:brian_ku...@lecotc.com]
Sent: Wednesday, January 28, 2009 2:01 PM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Switching Transformer Safety Standards
Greetings Transformer Experts,
We need to design a custom switching transformer that runs at 25kHz,
modulated 230VAC mains input and 4kVrms (.5A) output as part of a 4KV HV power
supply.
We want to design and test this transformer properly for safety so can
anyone
give us a list of construction and/or safety standards to cover UL, CSA,
Europe and any international IEC requirements?
We are not experts in the world of specialty transformer safety and
usually
rely on the manufacture for construction information but in this case we would
like to get more involved with the details and knowing what standards to
design to would be very helpful.
The end product will be used in a piece of laboratory equipment.
(61010-1).
Thank you and best regards,
The Other Brian
_
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.
-
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All emc-pstc postings are archived and searchable on the web at
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Graphics (in well-used formats), large files, etc. can be posted to
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For help, send mail to the list administrators:
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Mike Cantwell
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Jim Bacher
RE: Switching Transformer Safety Standards
Hello Brian, These are some general guidelines and are not necessarily complete. You should be able to have the transformer evaluated under 60601 as part of your product. You will need to obey all of the creepage, clearance and insulation thickness requirements of 60601. You will also need to consider any required electric strength test from primary to secondary. Additionally, consider the maximum temperature expected when selecting your insulation materials. How you construct the transformer will depend on the type of bobbin you intend to use. I presume the bobbin selection will be based on a trade-off of cost, size and efficiency. If the transformer can be large an inefficient, the safety will likely be easier to manage. I realize that a lot of what I stated may be obvious, but it covers a lot of the basics of switch-mode transformer safety. The devil is in the details. Verifying all of the required parameters on a small transformer can be difficult as there can be many creepage paths. With a 2 kW output power, I presume that this won’t be a small transformer. Ted Eckert Compliance Engineer Microsoft Corporation ted.eck...@microsoft.com The opinions expressed are my own and do not necessarily reflect those of my employer. From: Kunde, Brian [mailto:brian_ku...@lecotc.com] Sent: Wednesday, January 28, 2009 2:01 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Switching Transformer Safety Standards Greetings Transformer Experts, We need to design a custom switching transformer that runs at 25kHz, modulated 230VAC mains input and 4kVrms (.5A) output as part of a 4KV HV power supply. We want to design and test this transformer properly for safety so can anyone give us a list of construction and/or safety standards to cover UL, CSA, Europe and any international IEC requirements? We are not experts in the world of specialty transformer safety and usually rely on the manufacture for construction information but in this case we would like to get more involved with the details and knowing what standards to design to would be very helpful. The end product will be used in a piece of laboratory equipment. (61010-1). Thank you and best regards, The Other Brian _ 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.ieeecommunities.org/emc-pstc Graphics (in well-used formats), large files, etc. can be posted to that URL. 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.ieeecommunities.org/emc-pstc Graphics (in well-used formats), large files, etc. can be posted to that URL. 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.ieeecommunities.org/emc-pstc Graphics (in well-used formats), large files, etc. can be posted to that URL. 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: Switching Transformer Safety Standards
Insufficent information on end-use and input rating. none, or one, or some, or all of following: UL5085-x (binational std w/CSA66.x) IEC/EN61558-x UL1310/CSA223 From: emc-p...@ieee.org [mailto:emc-p...@ieee.org]On Behalf Of Kunde, Brian Sent: Wednesday, January 28, 2009 2:01 PM To: EMC-PSTC (emc-p...@ieee.org) Subject: Switching Transformer Safety Standards Greetings Transformer Experts, We need to design a custom switching transformer that runs at 25kHz, modulated 230VAC mains input and 4kVrms (.5A) output as part of a 4KV HV power supply. We want to design and test this transformer properly for safety so can anyone give us a list of construction and/or safety standards to cover UL, CSA, Europe and any international IEC requirements? We are not experts in the world of specialty transformer safety and usually rely on the manufacture for construction information but in this case we would like to get more involved with the details and knowing what standards to design to would be very helpful. The end product will be used in a piece of laboratory equipment. (61010-1). Thank you and best regards, The Other 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.ieeecommunities.org/emc-pstc Graphics (in well-used formats), large files, etc. can be posted to that URL. 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:
Switching Transformer Safety Standards
Greetings Transformer Experts, We need to design a custom switching transformer that runs at 25kHz, modulated 230VAC mains input and 4kVrms (.5A) output as part of a 4KV HV power supply. We want to design and test this transformer properly for safety so can anyone give us a list of construction and/or safety standards to cover UL, CSA, Europe and any international IEC requirements? We are not experts in the world of specialty transformer safety and usually rely on the manufacture for construction information but in this case we would like to get more involved with the details and knowing what standards to design to would be very helpful. The end product will be used in a piece of laboratory equipment. (61010-1). Thank you and best regards, The Other Brian _ 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.ieeecommunities.org/emc-pstc Graphics (in well-used formats), large files, etc. can be posted to that URL. 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.ieeecommunities.org/emc-pstc Graphics (in well-used formats), large files, etc. can be posted to that URL. 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
