Surge protector is a lie?

Surely a surge can come from all sorts. What if you live near a factory with massive motors? What if lightening strikes somewhere? The electricity board might have lightning arrestors, but I bet something still gets through.

The 11kV to 240V transformer which serves around 100 houses is just over the road from me. No overhead wires on either side. Can't see any overhead wires anywhere except the 330kV ones from a coal power station, and I think 11kV to a farm, which has it's own pole transformer, but there's never both voltages in the same place.

Since when did voltage get called tension?

Why twist them? And why not use the better conducting and less brittle copper?

I think it was originally German thing: "Spannung"

And Spanish: Alta tensión.

In an ABC cable the isolated aluminum phase conductors are twisted around an un insulated steel(alloy) neutral conductor. The steel wire handles most of the mechanical load and often survives a tree falling on the cable.

In a (nearly) balanced three phase cable, the neutral current is much smaller than the phase currents, thus the neutral connection can have a lower conductivity but better mechanical strength than phase conductors.

Aluminum has only slightly worse conductivity, is much lighter and cheaper as copper.

And being lighter it means that 40+ old creosoted poles could have a longer life.

When ever copper prices are high there is a spate of replacing bare copper 240V stuff on poles with bundles of twisted insulated aluminium conductors. I guess it is also possible to have bigger section conductors for the same weight. Important with more people buying EV's, heat pumps and heated tubs /pools.

Hmm.

But...

Whenever I've seen a pole down it's after a gale. Strong winds, not cable weight, finish them off. So the fatter cable you'll need for ally will be more of an issue than the reduced weight.

Andy

It isnt the wind drag on the cables that pulls the pole over.

If a tree falls during a storm on open wire copper lines, the flimsy wires will snap and the poles are saved. This of course cuts the electric distribution.

If a tree falls on a bundled cable (especially with a steel wire neutral), it is possible that the pole falls down, but the electric distribution may still continue, despite part of the cable has fallen to the ground.

A tree fell, down the block from our cabin. It sent a shock wave down the lines which tugged on our long feeder and ripped the wires off the front of the cabin, with the power and cable and old POTS wires on the ground. We didn't lose power or internet.

So instead of the water analogy, they use an analogy of.... weightlifting?

maybe a drive chain.

if you have ever seen a good close up electrostatic discharge the idea of a stretched cable snapping is not far off

Apparently I have to inform the power company when I install an EV charger. Like I'm gonna bother doing that.

You're lucky that didn't cause a short with the stupidly unfused incoming setting fire to the wood.