BT Fault Charges if fault is on customer wiring

Why solid core?

 

For IDC crimping.

 

Because IDC punch-downs, same reason infrastructure wiring is solid
core. Stranded can cheat and allow the insulation to deform instead of
displace.

 

If your prefer to used stranded for its flexibility and you know how
to use a soldering iron properly, you can remove a bit of insulation
and twist and tin the wires before punching them down. Works a treat.

 

That's fine, if it is you that will be making the connections, but it
won't be - it will be the BT installation engineer, who will probably
refuse to work with stranded cable.

 

With good reason too. If the IDC is biting into solder instead of
copper, the mechanical characteristics of the join will be quite
different. A long time ago I used to tin stranded copper wire to
connect it to brass terminals in mains plugs, because I thought it
made them neater, but they always worked loose.

Rod.

 

Sorry, but it's not fine. The BT installer is right to refuse
since his punch-down connectors are designed for solid wire.
The gap between the blades is designed to deform the solid
copper core making an air-tight joint or maybe a cold-weld. If
you try to use stranded wire then the wires will move out of
the way of the pressure points making a simple rubbing contact,
at best, that will fail quite quickly.

If the wire is soft-soldered, this may retard this wire
movement but the solder will "flow" away from the points of
pressure over time, resulting in a poor connection some time
later. This is often seen with screw-connectors tightened into
a soldered, stranded wire where ring connectors or ferrules
haven't been used to keep the soldered joint away from the
pressure.

Stranded wire is fine for crimp connectors or those with points
that pierce the strands as in RJ45 plugs or on those sockets
designed for the smaller stranded wire dimensions.