Unknown connector (Lemo?) - Page 1
Forum section: electronics / repair

author: inse
author_rank: Super Contributor
timestamp: October 03, 2024, 12:13:30 pm
content: I got hold of an old FUG power supply medium voltage, 1250V, 0.5AThe high voltage output is via two circular connectors, from the look possibly Lemo brand.The Lemo website is not really helpful for research.Is anyone able to identify the series? Inside diameter is about 15mm and the center contact is 2.5mm.I am not sure whether this connector is really suitable for high voltage, though there is a decent Teflon sleeve, the center contact can almost be touched with a finger…

author: inse
author_rank: Super Contributor
timestamp: October 03, 2024, 12:18:55 pm
content: The other question was whether I would be willing to pay for a possible Lemo counterpart or rather mount 4mm safety sockets.Though they are only rated for 1000V - what do you think?

author: tggzzz
author_rank: Super Contributor
timestamp: October 03, 2024, 12:20:16 pm
content: Quote from: inse on October 03, 2024, 12:13:30 pmMay be worth having a look at this cataloguehttps://www.hivolt.de/fileadmin/hivolt/pdf/Catalog_HV_Cable_Connectors.pdforhttps://www.metabee.com/blog/post/high-voltage-connectors-and-cautions-for-use

author: Roehrenonkel
author_rank: Frequent Contributor
timestamp: October 03, 2024, 06:07:10 pm
content: Hi inse,if there is nothing on the connector (like in my photo),then it's not a Lemo.Maybe Fischer?Good luck

author: inse
author_rank: Super Contributor
timestamp: October 03, 2024, 06:32:24 pm
content: Yes, I was already wondering because Lemo usually marks their parts.https://fischerconnectors.com/Almost as helpful for searching as Lemo 😖 simply too many variants but thanks anyway.What about conversion to 4mm safety connectors?

author: Roehrenonkel
author_rank: Frequent Contributor
timestamp: October 03, 2024, 09:58:36 pm
content: Hi,in my lab i have a FUG 140-1250 with SHV-BNCs.To connect to my tube-test-fixtures i use 4mm safety-plugs. ;-)Take care & good luck.

author: inse
author_rank: Super Contributor
timestamp: October 04, 2024, 02:23:36 am
content: Thanks to all, but instead of sourcing an exotic and expensive plug, I am going to fit 4mm safety connectors to the unit.

author: tooki
author_rank: Super Contributor
timestamp: October 04, 2024, 10:20:26 am
content: Quote from: Roehrenonkel on October 03, 2024, 06:07:10 pmLack of markings is not proof that it isn’t Lemo.I have a bunch of old Lemo connectors at work that have no markings. The cable-mount plugs and sockets always do, but the panel-mount ones often do not. (Some of the oldest cable-mount ones have only a Lemo logo, but no other markings.)

author: tooki
author_rank: Super Contributor
timestamp: October 04, 2024, 10:31:17 am
content: Quote from: inse on October 03, 2024, 12:13:30 pmThe catalogs are where the real info is. Here’s the relevant one:https://web.lemo.com/img/resources/catalog/ROW/UK_English/high-voltage-connector-Y-S-E-05-LEMO.pdfIt looks like probably either 1Y or 2S series to me, based on your measurement.Quote from: inse on October 04, 2024, 02:23:36 amAt the absolute bare minimum, use safety banana jacks. And then only use non-stackable safety banana plugs.

author: inse
author_rank: Super Contributor
timestamp: October 04, 2024, 04:55:50 pm
content: I have browsed through the catalogs of Lemo and Fischer already but haven’t been successful.A 2.5mm drill bit fits perfectly as center contact and neither of them seems to have a matching series.But never mind, I am going to retrofit a 4mm safety connector.Funny thing is that the plugs are available up to 1.5kV while the sockets are only specified for 1kV max.

author: tooki
author_rank: Super Contributor
timestamp: October 04, 2024, 05:00:32 pm
content: Quote from: inse on October 04, 2024, 04:55:50 pmI can only guess that they assume you can insulate the sockets more yourself by spacing them farther apart, mounted in an insulator.

author: inse
author_rank: Super Contributor
timestamp: October 07, 2024, 03:11:47 pm
content: So, this is how I did it:4mm safety connectors with additional isolation.Maybe there is an offer on eBay for the original plugs, but at €42,75 a piece - no thanks

author: tooki
author_rank: Super Contributor
timestamp: October 08, 2024, 07:22:46 am
content: FYI, by all accounts, LEMO connectors cost far less when ordered directly from LEMO. 100 franc (so presumably 100 euro) minimum order IIRC.