Proper tools for replacing thermal fuses. - Page 1
Forum section: electronics / repair

author: Traceless
author_rank: Frequent Contributor
timestamp: May 25, 2024, 10:38:37 am
content: Hi everyone,axial leaded thermal fuses are usually crimped into a circuit in appliances coming from the factory. I do know that you can get away and solder them in if you're quick and maybe attach some large metal item as heat sink inbetween the lead and the fuse body. Still crimping seems to be the better option if you do not want to weaken a new fuse. Technically I guess you could use spade connectors but the preinstalled connectors usually seem to be crimped on both ends as opposed to spade terminals which are plugged on one end. Does anybody know what type of connectors are used by the manufacturers? Using search engines and the term "thermal fuse crimp connector" I get some hits for instancethisone. But using the search term on mouser or digikey does not yield any results, do those connectors have a "proper" name, also is there a special crimping tool for those terminals? Obviouslythose oneswould only work for one end if you don't want to permanently install the tool in circuitCheers Traceless.

author: Haenk
author_rank: Super Contributor
timestamp: May 25, 2024, 02:23:23 pm
content: Just a random Amazon offer (probably dozens of other sellers):https://www.amazon.de/dp/B0C6T3T41KThe long "tubes" are the ones you need, wire goes in from both sides, crimp, done. For a thermo fuse, removing the plastic might be a really good idea, as that would likely melt, maybe replace by heatshrink.

author: Traceless
author_rank: Frequent Contributor
timestamp: May 26, 2024, 09:57:53 am
content: Thanks for the work-around idea, I took another look around and after some time I think I actually found aviable alternativeon Aliexpress that does not require to cut off insulation. Still not sure how those are actually called, unless "U-shaped Terminal Tab Cold Inserts Connectors Cold Terminal Small Teeth Fascia Terminal" is the actual official name for this type of crimp connectors

author: wraper
author_rank: Unknown
timestamp: May 26, 2024, 10:04:32 am
content: Thermal fuses in transformers were always soldered IME. Crimping solid wire asks for failure by itself with connectors not designed for that like in posts above. Barely any connectors support solid wire and most of those rare exceptions are data connectors.

author: Traceless
author_rank: Frequent Contributor
timestamp: May 26, 2024, 10:14:56 am
content: I quickly looked up some examples of how thermal fuses are often installed in tools/appliances see videos below. Maybe in some cases they are soldered but often they are not and for good reason IMO.https://youtu.be/7gDTC33I4YI?feature=shared&t=369https://youtu.be/Xv-r2dPGjh0?feature=shared&t=737

author: JohanH
author_rank: Frequent Contributor
timestamp: May 26, 2024, 10:30:41 am
content: This assumes the thermal fuse is on a PCB. I have only tried it this way, so I can't say about other installations.1. Fill a small cup with water.2. Place the new thermal fuse onto the PCB and bend the legs slightly so that it is kept in place. It helps if the legs are kept long.3. Turn the PCB around and place it onto the cup so that the thermal fuse is submerged.4. Solder.

author: wraper
author_rank: Unknown
timestamp: May 26, 2024, 10:34:23 am
content: Water is completely unnecessary and nonsensical. A metal clamp on the wire, like forceps will provide more than enough heatsinking.

author: jdragoset
author_rank: Frequent Contributor
timestamp: May 26, 2024, 05:00:18 pm
content: https://www.amazon.com/Thomas-Betts-WT111M-Insulated-Terminals/dp/B0018LD2PU

author: wraper
author_rank: Unknown
timestamp: May 26, 2024, 07:11:22 pm
content: Quote from: jdragoset on May 26, 2024, 05:00:18 pmAgain, you should not crimp solid wire into usual connectors, it's very unreliable.

author: Traceless
author_rank: Frequent Contributor
timestamp: May 26, 2024, 08:03:24 pm
content: Quote from: wraper on May 26, 2024, 07:11:22 pmAgreed, that's why I asked for the proper tools and crimp connectors used in the factory.

author: SeanB
author_rank: Super Contributor
timestamp: May 26, 2024, 08:10:47 pm
content: Bootlace ferrules work well, thin wall, and crimp onto the wire and fuse well. Just slide thermal fuse wire in one end, and wire the other, and crimp. might have to use a slightly bigger one, but they are easier to find over bare small crimp connectors. But I just use long nose pliers and solder them in, especially with those like 130C and 200C versions. 70C you really want to crimp, or leave the leads long, and sleeve them after crimping.

author: soldar
author_rank: Super Contributor
timestamp: May 27, 2024, 08:29:37 am
content: A good twisted splice should also be reliable.

author: Hamelec
author_rank: Regular Contributor
timestamp: May 29, 2024, 09:12:40 am
content: https://hl-elektroshop.eshop.t-online.de/Quetschverbinder-fuer-Temperatursicherung-1001506