Dear All, I have submitted an ac input to dc output switching power supply for NRTL approval. One deviation is that the primary ac insulated capacitor is too close to the earthed chassis and that the insulation cannot be relied to provide the required basic insulation.
1. What is the group's opinion regarding this point? I have personally seen many Listed/Recognized units with clearance distance less than 2.0 mm to the earthed chassis without any additional insulation to provide the required insulation. In fact, I am holding a switching power supply by a reputable manufacturer with only approx. 0.7 mm between the primary and earthed chassis. This power supply is UL Recognized and TUV approved. 2. There is a UL Pag 156002 regarding this issue, but it seems that some NRTL engineers are using their own judgement and approving units at their own discretion. This e-mail message may contain privileged or confidential information. If you are not the intended recipient, you may not disclose, use, disseminate, distribute, copy or rely upon this message or attachment in any way. If you received this e-mail message in error, please return by forwarding the message and its attachments to the sender. PETER S. MERGUERIAN Technical Director I.T.L. (Product Testing) Ltd. 26 Hacharoshet St., POB 211 Or Yehuda 60251, Israel Tel: + 972-(0)3-5339022 Fax: + 972-(0)3-5339019 Mobile: + 972-(0)54-838175 ------------------------------------------- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson: pstc_ad...@garretson.org Dave Heald davehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
