What's wrong with this?

[mike93lx]

What i wrote "overhead HVMV service caused catastrophical fires"
Overhead HV MV . The HV part is transmission. That caused the fire if the newspaper info I have is correct.
And I love the leaning MV pole distribution networks with transformers at the top.
Great for the company selling back up residential generators.
Ola

We were talking about residential overhead. No idea why HV is relevant

 

[wyliesdiesels]

Mike said
"Much of this country has overhead service and switching to underground is prohibitively expensive."
That overhead HVMV service caused catastrophically fires in California and I think it also led to the utility went broke.
Some of the fire problems may have been the result of very poor relay protection systems.

Profit Gouge & Execute has gone broke many times only because they send their profits to executive pay & shareholder bonuses instead of infrastructure repairs.

but the state props them up every time.... so they are still in business

you should see how bad their infrastructure is here... poles with 3 phase transformers leaning @ 20°

the fire that burned down paradise was caused by a HV line coming from a damn that had really old insulators. the tower had recently been replaced but the PoCo decided not to replace the decades old insulators and associated hardware. so the metal wore thru causing the line to drop on the grounded tower. this in turn caused sparks to land on dry brush. no relay protection system can prevent that.

A large number of utilities around the world use HV cable networks, and the longer ones must be HVDC.
Reduces the cost for purchasing right of way and yearly tree felling.
And does away with fire hazard and lightning power cuts
Many of the substations are also indoor GIS, which occupy around 12 % of an outdoor substation.
(My favorite outdoor substation in the US is the one near the Audubon facility close to the river in New Orleans, where large birds nest close to phases. Station also occupies a large area where I BELIEVE that real estate is very expensive)
And energy cost for consumers is around the same as in the US.
For off shore wind farms there is no alternative to cable.

Ola

not sure what that has to do with topic at hand

 

[MBfreak]

no relay protection system can prevent that.
A modern protection system disconnects both ends of a HV line with even a VERY short ( < 20 ms) single, 2 phase or three phas groundfault in < 40 ms.
If the line is equipped with differential protection, even shorter.
The energy stored in the line capacitance ( Upk*Upk* line capacitance/2 J) is the main spark culprit.

And thats my latest here.

Ola