Plug Melted - Potential causes?

[Rehab chic]

You clearly can't, judging by your rambling replies and selective answering of questions.

[scottyp123]

If he is a Wago rep then he certainly isn't doing them any favours. I've never known someone with such zealousness over a product before. I cant even convince some people to use grommets so there is no chance anyone will ever be remotely interested in something like this. I might even go back to using terminal blocks in light switches now instead of wagos just to piss him off that bit more.

[Rehab chic]

I just twist the wires together and wrap them in foil. No fires so far.

[ATG]

RayTay said:

Rehab chic said:

Wagos don't apply any torque.

You need to do some research.

Torque isn't really the issue in either a wago or a screw terminal. You want a good contact area to be maintained between the wire and the contact in the connector and in practice that means you want them to be clamped together with a fair amount of force. The "problem" with a screw terminal is that the system's modulus of elasticity is extremely high; i.e. a huge force is required to change its length by a small amount, and therefore a very small movement can also drastically reduce the force. You can think of a screw terminal as being two springs pushing against each other. One spring is the threads in the screw that bend back along the length of the screw as it is tightened against the strands of the wire which are themselves the second spring. The wire stands are a really st spring. If they shift a bit you're relying entirely on the extremely stiff spring of the screw threads to move lower in the connector while still maintaining adequate clamping force. Such a shift could be caused mechanically by something yanking the cable, by thermal expansion temporarily squeezing the wire hard enough to cause plastic deformation that leaves the connection loose once it cools. And of course once the connection loosens a bit, the screw itself is no longer clamped as firmly in its threads, so less torque is required to overcome the friction in the threads and vibration can start to unscrew the screw further. This system would work much better if you could somehow make the screw behave like a much less stiff spring with more travel. That way the wire could deform and rearrange itself and the "screw" would happily move lower while maintaining a virtually unchanged clamping force. One obvious way to achieve this is to replace the screw with a spring, if that can produce a high clamping force. If I was going to design an ATG super connector, I'd probably use a stiff spring to clamp the wire, but use a screw to compress the spring into the wire. That way you'd get the benefit of the screw producing a massive clamping force while the spring would give the system the ability to remain very tightly clamped in spite of the wire packing down or deforming plastically.

Edited by ATG on Tuesday 15th June 12:17

[dhutch]

RayTay said:

... choc bar connector strip sales dropping off substantially.

Finally!