Is this a copper splice?

[jimmyc_]

Hello chaps!

Repair beginner here!

I need your help to identify this clamp/splice/swage for a thermal fuse. This looks common but i can only find aluminum ones.

Can aluminum ones work in place of the copper ones?

What type of crimps should I get?

[Ian.M]

No, its probably brass.  Pure(ish) copper is too soft to make reliable thin crimps from.

For a repair job, get any crimps that are rated for a gage of wire that equals the CSA of the wires in your photo + the CSA of the thermal fuse lead, cut off the terminal part (easiest to do if you start with a ring terminal as its flat between the crimp and the ring), and just use the crimp part.   For production, look at bare crimp ferrules from a specialist supplier, but you'll probably want a heaver wall thickness than is standard if using them as splices.

[jimmyc_]

Cool thanks Ian.M!

What does CSA refer to?

[Ian.M]

Cross Section Area, equal to \$\pi\cdot D^2/4\$ for bare solid wire and approx. \$0.9\cdot\pi\cdot D^2/4\$ for fine stranded wire.  For coarse stranded wire, add up the CSAs of the individual strands as one cant assume circular close packing.

As you have a US flag, the Wikipedia table of AWG wire sizes may be useful to aid choosing suitable crimps.
https://en.wikipedia.org/wiki/American_wire_gauge#Tables_of_AWG_wire_sizes

Edit: Sorry, had a brainf--t and gave the formula for circumference, not CSA.    Now fixed.

[jimmyc_]

Much appreciate your advice!

[jimmyc_]

Btw, is there a special crimper I have to get, in order to crimp the two wires together?

[electronicsengineer]

Yes, I need it, something like that...

[aqibi2000]

Just solder it then heat shrink

[Alti]

Just solder it then heat shrink

It is going to be really challenging to solder a 87oC thermal cut-off but with proper technique I think it could be done reliably. However, heat shrinking it reliably is going to require some witchcraft skills.

[Ian.M]

Just solder it then heat shrink

Good luck with that!  It can be done but to do so so the connection is secure, without blowing the thermal fuse from the heat of the soldering is a royal PITA.  Also, mains connections must *NEVER* rely on solder alone, but must always be mechanically secure before the solder is added, so you'd need to form loops in the ends of the thermal fuse leads to hook the mains wire through, which would significantly reduce the lead length available to heatsink it to stop it blowing, and significantly increase the time to fully wet the joint, increasing the odds it blows as you solder it.

It is going to be really challenging to solder a 87oC thermal cut-off but with proper technique I think it could be done reliably. However, heat shrinking it reliably is going to require some witchcraft skills.

Yep, I wouldn't tackle it on a bet, without a custom fitted solid copper heatsink to clamp over the fuse body and leads + plumber's freezing spray to chill it right down before hand!

Yes, I need it, something like that...

Yep, that will do the job.  So will Chinese knockoffs of that brand-name ratchet crimper at a fraction of the price.   Don't get the non-ratchet flat plate scissors style tool with wire strippers and bold cutters built-in as it very difficult to get enough pressure to make an electrically and mechanically secure crimp, and its far too common nowadays for them to be made of far too thin mild steel that buckles sideways under load.

If you are anyway near a good 'big box' hardware store, see what they've got on their electrical aisle, otherwise trawl thorough this amazon search:
https://www.amazon.com/s?k=ratchet+crimping+tool+terminal+kit
till you find one that looks like the above, with a terminal kit including ring terminals.  I wouldn't trust a crimp ferrule as they are intended to deform slightly for good contact in a screw terminal so have much thinner walls than a regular crimp terminal, and usually less crimping pressure, so avoid those kits for this job. $25-$30 should see you good, with a tool that will last you for years if you look after it.

[jimmyc_]

Thanks for all your advice, chaps!