Soldered wire in screw terminals

[nice_mark]

Hi everyone, my first post, on this forum.
I have a question that I have been unable to find any standards or advice on.

When wiring equipment, and sometimes industrial equipment years ago, if we terminated cables in screw terminals, we would often dip tin the ends of the leads. There are some advantages.
1. The soft electrical solder would flatten nicely under the pressure of the screws, providing a good contact surface.
2. It avoided birdcaging and splaying of strands.
3. The dent in the solder formed by the screw (even if shielded with a spring steel blade, as some are), made the cable less able to pull back out, in the case of mechanical strain

Now I have been challeged that this is bad practice, by another engineer, on power tansfer grounds. Yet I can remember doing this on high power 3 phase equipment, supposedly for that very reason.

Does anyone know of any standards on this ? IPC-6-10 and Mil-STD 2000A use words which suggest this would be advantageous, but do not specifically mention screw type terminations. I don't remember any specific references to it when I was doing my inspectors studies, some years ago.

Failing knowlege of standards, do you have any views on this ?

 

[nickblake]

stranded cable IE flex should be terminated in a ferruel .to stop any frayed ends etc , i dont think soldering is permitted any more , i may well be corrected ,sure ive seen it in the regs but cant put my hand on it at the mo will keep you informed

 

[acat]

Only thing relevant in BS7671 is 526.2 which states "Where a soldered connection is used the design shall take account of creep, mechanical stress and temperature rise under fault condition" cant think of anything that says its bad practice.

Hope that helps a bit


Chris