Mike, it depends on your perspective. Those of us who use AC line filter/power inlet combination units are forced to have both the X and Y capacitors placed on the AC mains side of the fuse. Some switchers contain an X capacitor which is usually located on the side of the fuse opposite AC mains power (assuming that said SMPS has a fuse built-in). It is probably safest to place fuses on the mains side of any filter devices, but it is not always practical.
Correct me if I am wrong, but aren't X and Y capacitors built so that if there is a fault that they will be in an open state? Steve Chin StreamLogic Corp. Menlo Park, CA, USA [email protected] -------------------------------------- List-Post: [email protected] Date: 12/17/96 1:14 PM To: Steve Chin From: [email protected] On the same subject, Where do you put the AC mains fuse relative to the "X" capacitor used for the EMI filter? How does the "accross the line" safety rating of the capacitor affect this answer? Specifically. Would you put an X cap in the unfused area of the AC inlet like the EMC fellow wants? What about a "Y" cap? Mike ------------------ RFC822 Header Follows ------------------ Received: by sledgehammer.com with SMTP;17 Dec 1996 13:12:13 -0800 Received: from ruebert.ieee.org by oz.sledgehammer.com (SMI-8.6/SMI-SVR4) id CAA02749; Tue, 17 Dec 1996 02:57:20 -0800 Received: (from daemon@localhost) by ruebert.ieee.org (8.7.5/8.7.3) id BAA12742 for emc-pstc-list; Tue, 17 Dec 1996 01:54:56 -0500 (EST) From: [email protected] List-Post: [email protected] Date: Tue, 17 Dec 1996 01:51:07 -0500 Message-ID: <[email protected]> To: [email protected], [email protected] Subject: Re: regarding fusing ac-mains Sender: [email protected] Precedence: bulk Reply-To: [email protected] X-Resent-To: Multiple Recipients <[email protected]> X-Listname: emc-pstc X-List-Description: Product Safety Tech. Committee, EMC Society X-Info: Help requests to [email protected] X-Info: [Un]Subscribe requests to [email protected] X-Moderator-Address: [email protected]
