HP 3457A Schaffner EMI/IEC - Page 1
Forum section: electronics / beginners

author: sairfan1
author_rank: Frequent Contributor
timestamp: January 15, 2021, 03:34:25 pm
content: I bought HP 3457A a while ago it has its original Schaffner installed, while looking at some forums i decided to replace mine, its part number is FN 323-3/05 but when i searched its not available on DigiKey, mouser has but in a quite different package, and i could not find it anywhere else, i also saw it on some unknown stores (at least unknown to me)can someone help me where from can i buy with original fitting, or should i consider something else,

author: Terry Bites
author_rank: Super Contributor
timestamp: January 15, 2021, 05:34:20 pm
content: its an old product but there are plenty of similar IEC inlet filters that will bolt straight in.https://www.schaffner.com/products/emcemi/"A Shaffner" is not a generic term.I've got soft spot for a Bulgin, but there are so many to choose from Deltron EPCOS,Hirschmann,Qualtek, Roxburgh, EMC, RS PRO, Schaffner, Schurter ,TE Connectivity,XP Power- to name but a few.Definitely do not buy a medical grade- far less leakage current but poorer performance on EMC.

author: bdunham7
author_rank: Super Contributor
timestamp: January 15, 2021, 05:46:00 pm
content: You just need a standard 3-amp (not a medical-grade) IEC inlet, like this:https://www.mouser.com/ProductDetail/EPCOS-TDK/B84771A3003A000/?qs=BZBei1rCqCDMETB4Stn29Q%3D%3DJust look closely at all the dimensions and mounting hardware to make sure it fits nicely--they come with a variety of minor differences.

author: sairfan1
author_rank: Frequent Contributor
timestamp: January 15, 2021, 08:45:32 pm
content: thanks, one more thing about Schaffner, i read about it that if we do not use our device for a while that causes it to burn out, can you advise if that's true how often we should turn our device ON like every month, three months etc.

author: wizard69
author_rank: Super Contributor
timestamp: January 15, 2021, 09:55:39 pm
content: I can only comment based on instruments at work that are not plugged in all the time. In a nut shell I really don't think it matters as long as you have a high quality and modern input filter. On lesser quality hardware (no name chinese) and old stuff you could very likely have issues. In one case I saw a new, out of the box, EMI filter fail so yea the cheap stuff is a question mark.Quote from: sairfan1 on January 15, 2021, 08:45:32 pmI'm assuming you are talking about EMI /IEC input filters here. Schaffner is a manufactures name which implies very little out of context.QuoteIf that where to happen I'd make sure to replace it with something more reliable. You should be able to go years without issue. In some cases I'd suggest a separate line filter from the IEC inlet.

author: srb1954
author_rank: Super Contributor
timestamp: January 16, 2021, 06:37:15 am
content: Quote from: sairfan1 on January 15, 2021, 08:45:32 pmI think the failure mode in the Schaffner filters (and the dreaded RIFA capacitors) is by moisture absorption into the filter capacitors over time thus lowering the insulation resistance.One way that this could be avoided is by having the equipment turned on continuously and running at a sufficiently high internal temperature to drive out any moisture from the components. This would protect the filters but wouldn't do much for the life of the rest of the equipment.Another way is to dehumidify the environment down to extremely low levels of relative humidity thus drawing moisture out of the components over time. Beside making the environment very unpleasant to work in this would also considerably magnify any build-up of static electricity so is not a practical solution in a workshop.Best approach is to just replace the filters although it is less critical where you have 120V mains supply. For areas with 230V mains supply it is essential to immediately replace the Schaffner filters and RIFA capacitors.

author: sairfan1
author_rank: Frequent Contributor
timestamp: January 18, 2021, 03:32:17 pm
content: What humidity level is ideal for a lab where we have this kind of electronic devices. I'm using device at 110v, what I'm going remove is a Made in Switzerland filter, and will be buying new from Mouser TDK brand, not sure if it will be a Chinese version. Though my device run for more than 15 minutes peacefully but i turned it off and decided to replace the filter as its advised in forums.

author: wiesl
author_rank: Contributor
timestamp: March 16, 2021, 02:23:45 pm
content: Used the Schaffner C14 IEC Gerätestecker mit Filter, Faston-Anschluss, 3A, 250 V ac, Tafelmontage RS Best.-Nr.:454-0934 Herst. Teile-Nr.:FN 9222-3/06Works perfect.https://at.rs-online.com/web/p/iec-filter/4540934Wiesl