I think I solved my doubt with your help, and reading carefully the IEC60335-1. This was my conclusion so far:
IEC60335-1 says in page 177 (item 29.1): For conductive patterns on printed circuit boards, except at their edges, the values in the table between parts of different polarity may be reduced as long as the peak value of the voltage stress does not exceed: - 100V per mm with a minimum distance of 0,5mm, if not protected against the deposition of dirt. So I suppose that if I have a Flyback transformer, with the primary divided, the peak voltage between pins will be half the DC voltage. With 400Vdc maximum in the bulk capacitor, the peak voltage will be 200V in half of the primary (while the switch is ON), so the clearance distance will be 2mm. Am I right ? Now considering the transformer construction. Does anyone have experiences to comply a transformer with IEC60335-1. My doubt is about the wires that leave the bobbin and go to the terminals of the coil. Do I need to insulate them, in order to comply with the creepage distances ? Thanks for the comments about IEC60335-1. Günter J. Maass EMBRACO S.A. Constantin Bolintineanu <[email protected]>@ieee.org em 03/04/2001 11:03:08 Favor responder a Constantin Bolintineanu <[email protected]> Enviado Por: [email protected] Para: "'[email protected]'" <[email protected]>, [email protected] cc: Assunto: RE: IEC60335-1 1. The subject Voltage are r.m.s values: under Item 2, Definitions, the item 2.1 specifies as follows: where the terms voltage and current are used they imply r.m.s. values, unless otherwise specified. 2. In my opinion, YES. In fact you have to provide the required clearance and creepage for insulation in the PRIMARY circuit. Respectfully yours, Constantin Constantin Bolintineanu P.Eng. DIGITAL SECURITY CONTROLS LTD. 3301 LANGSTAFF Road, L4K 4L2 CONCORD, ONTARIO, CANADA e-mail: [email protected] telephone: 905 760 3000 ext 2568 www.dscgrp.com -----Original Message----- From: [email protected] [mailto:[email protected]] Sent: Tuesday, April 03, 2001 8:49 AM To: [email protected] Subject: IEC60335-1 Hi group A question about clearance and creepage distances indicated in IEC60335-1. The table 13 shows limits of 3mm (creepage) and 2.5mm (clearance) for a working voltage > 130V and < 250V. I still didn't find out if this voltage is RMS or peak value. Anyway, considering a Flyback converter, I know that I will need to comply with these distance limits between primary and secondary circuits. To reduce EMI problems, I can reduce the capacitance of the primary. I can divide the primary in two parts to do this. Doing so, I will need an auxiliary pin in my coil to connect the center tap of the primary. This pin can be cut out later, leaving a short stump with the soldering. My question is: Does the distance between the primary terminals of the transformer, and the center tap of this primary, need to comply with the distances indicated by IEC60335-1? Thanks in advance. Günter J. Maass EMBRACO S.A. ------------------------------------------- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: [email protected] with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson: [email protected] Dave Heald [email protected] For policy questions, send mail to: Richard Nute: [email protected] Jim Bacher: [email protected] All emc-pstc postings are archived and searchable on the web at: http://www.rcic.com/ click on "Virtual Conference Hall," ------------------------------------------- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: [email protected] with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson: [email protected] Dave Heald [email protected] For policy questions, send mail to: Richard Nute: [email protected] Jim Bacher: [email protected] All emc-pstc postings are archived and searchable on the web at: http://www.rcic.com/ click on "Virtual Conference Hall," ------------------------------------------- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: [email protected] with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson: [email protected] Dave Heald [email protected] For policy questions, send mail to: Richard Nute: [email protected] Jim Bacher: [email protected] All emc-pstc postings are archived and searchable on the web at: http://www.rcic.com/ click on "Virtual Conference Hall,"
