Path: ...!Xl.tags.giganews.com!local-3.nntp.ord.giganews.com!news.giganews.com.POSTED!not-for-mail NNTP-Posting-Date: Wed, 04 Dec 2024 19:58:50 +0000 From: Joe Gwinn Newsgroups: sci.electronics.design Subject: Re: electrical deaths Date: Wed, 04 Dec 2024 14:58:19 -0500 Message-ID: References: <2m8pkjpasi6dca20k2dgp0sj1pl07so9ek@4ax.com> <4hfskjlodq61l8dc82dfakqs0bv1vi7721@4ax.com> User-Agent: ForteAgent/8.00.32.1272 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Lines: 77 X-Usenet-Provider: http://www.giganews.com X-Trace: sv3-sbA3edkLgdd+YxGsbllxzMgFnTFWl5+RsN1IiEf7/PvfrnihnrzDqEF1NjrEddInBd20QFqweAyWLox!swZXCcE/Mth/Ud0e3w65oj1MySuAerl/vW08uTFCZCntJ79BWkMc52QeJQY7CzjxERAwGQk= X-Complaints-To: abuse@giganews.com X-DMCA-Notifications: http://www.giganews.com/info/dmca.html X-Abuse-and-DMCA-Info: Please be sure to forward a copy of ALL headers X-Abuse-and-DMCA-Info: Otherwise we will be unable to process your complaint properly X-Postfilter: 1.3.40 Bytes: 4508 On Tue, 3 Dec 2024 19:23:41 -0800, Joerg wrote: >On 12/3/24 9:16 AM, Joe Gwinn wrote: >> On Tue, 3 Dec 2024 12:10:54 +0100, Arie de Muijnck >> wrote: >> >>> On 2024-12-03 00:20, Joe Gwinn wrote: >>> >>> ..... >>>> >>>> I don't either, because the approved euro terminal strips don't >>>> provide plates for the smaller wire sizes. I also use the euro >>>> terminal strips inside appliances, and if I'm connecting finely >>>> stranded wire, I tin the wire with 63-37 solder to consolidate it, and >>>> clamp that. >>>> >>>> Joe Gwinn >>> >>> >>> DON'T! The tin will flow slowly under pressure, and loose the connection. >>> It was a common habit in the Netherlands until forbidden. With a reason. >> >> Yes, I know. Only done for small wires at low power. >> > >If it's mains stuff the arcing can still spark a fire. I've had numerous >cases where I found signal or control wires were tinned and then >clamped, and the connections failed or became erratic. Usually after >many years. I guess the best answer is yet another war story: For short-term lab stuff, I don't worry about such details, but with power it's far more important to have mechanically solid connections - no test probe and alligator-clip jumpers (like I used in my youth) here. When in 2019 I was figuring out the wiring of a friend's 3-phase Dahlander two-speed 240 Vac (60 Hz) 5HP motor (that powered a Clausing Colchester Triumph 13" lathe he was restoring), it had to be all 4mm banana plugs and jacks. My friend's shop had been a commercial shop, and so had very high current available - not quite arc flash territory, but can be dramatic. The problem was that when the lathe was received the motor's wire markers were missing, and so had to be deduced from measurements. The motor had six leads (only the frame is grounded) and one connects three power wires, with or without the three shorting jumpers. One configuration is full speed, another is half speed, al all others are melt-down with drama and smoke. Measuring winding DC resistances with probes did not work - contact resistances too large and unstable. Likewise capacitances and winding inductances. For this effort, I made a six-bar terminal strip, brass bars on a wood base. Each bar had a screw-terminal (for the six motor wires), and two 4mm diameter reamed holes (for the banana plugs, power and jumper). The bars are 0.25" wide by 0.75" high by 2.0" long, made of alloy C360. Long saga, but succeeded, and the lathe has been in regular use since then. For operational stuff, the solder tinning is only for low-voltage (< 50V) control wiring. What I sometimes do is to thread the stranded wire through some brass tube, and solder wire to the brass tube. Or crimp a spade or ring terminal to the wire, for use in screw-type barrier strips. One can also crimp the brass tubing, with the right tool. I've had this one for at least 40 years. .. Joe Gwinn