Get rid of the GFI breakers and your LISNs won't trip an ordinary breaker. I can' t think of a reason the isolation XFMR would cause an increase in noise, unless the XFMR broke the safety ground connection to the LISN cases. Then the LISN input caps are not able to fulfill their filtering function.
From: [email protected] Reply-To: [email protected] List-Post: [email protected] Date: Mon, 10 May 2004 22:14:29 +0530 To: [email protected] Cc: [email protected], [email protected] Subject: Re: Isolation Transformer at the LISN input Dear Lawler, Isolation transformer is recommended by the LISN manufacturer. LISN is an integral part of the EMI receiver (PMM7000) used for precompliance testing. Without an isolation transformer in the LISN input the circuit breaker which controls the power input to the LISN gets tripped. But when an isolation transformer is introduced the floor level noise (without connecting any DUT for test) goes upto 40 dB (in the frequency range of 150 to 200 KHz). Sincerely K.Balasubramanian Sr.Engineer, Hardware. [email protected] Sent by: [email protected] 05/09/2004 09:47 AM Please respond to pat.lawler To: [email protected] cc: Subject: Re: Isolation Transformer at the LISN input What standard are you using, and where do you see an isolation transformer requirement? On Thu, 6 May 2004 17:26:43 +0530, [email protected] wrote: >Apart from the power rating, what are the other requirements >(specifications) for the isolation transformer that is to be used in the >power input to a LISN that is used for testing the conducted emission. This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ieee-pses.org/ To cancel your subscription, send mail to: [email protected] with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: [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.ieeecommunities.org/emc-pstc
