these powerlines are trunk feeds are they not? They'd be stepped down etc.. before reaching people's homes.. would the feedback from noisy end-users reach these lines?
Hi PH how are you today?
When installing electrical equipment on larger commercial projects, and nowadays even some of the smaller projects, builders are requiring their own PFCC control cabinet. If the business doesn't install this on their own, the utility company will install theirs on the line and then the customer pays for the correction.
I would have to say the utility companies are aware of whats going on.
And as far as power lines being stepped down yes they are stepped down to 2400/4160Y in some cases, which has been around for years. Then you have the 7200/12470Y which is the new standard voltage for neighborhoods. Outside of the city almost all lines are 7200 that connect to homes.
2400/4160Y Simply means each line to ground is 2400 volts. And when 2 lines are touched to each other then you get 4160 volts. The Y is the configuration of the windings in the transformer. You can have a Delta or a Wye. Once the voltage hits the transformer on the pole or in the big green transformer boxes you see in the alleys it is then converted back to a Delta configuration again this is determined by the winding configuration of the transformer itself.
Odds are if you are in an old established neighborhood in the city or suburbs, you have the 2400/4160Y. However if you live in an area with a lot of growth, odds are you have the 7200/12470Y.
I personally seriously doubt any coupling was being done in a neighborhood unless a substation was very close by. Or a high voltage transmission line was very close.
This in contrast to the UK is much less. While they started systems at 3300 volts phase to ground and progressed to 6600 then finally 11,000 volts phase to phase. Which today is the most common distribution voltage in the UK. One major difference in the US verses the UK is the UK uses one large substation full of transformers to serve an entire neighborhood. 2MW is not uncommon. On the other hand in the US the utility companies tend to mount transformers closer to the customers, like on poles or in the green boxes. Closer to the customer is a better design.
When I was a kid we took 8 foot fluorescent lamps and drove to the substation and they would light up if you walked close enough to the fence around the substation. but would go out as soon as you started walking away. Coupling is possible but I doubt SM was coupling to a neighborhood power line.
Now to address the high voltage transmission lines. The common voltages in the US are 138, 230, 345, 500, and 765 KV's. I believe the highest operating voltage is around 1.1MV in Russia. Anything less than 110KV is considered sub transmission voltage. Anything over 230KV is considered extra high voltage. Only substations see any of this high voltage. Primary customers who use large amounts of electricity are limited to 13,600 volts and less. Homes are limited to 240 volts. There are a few exceptions which can receive up to 69,000 volts directly from the substation.
In order to work on the high voltage and extra high voltage lines without turning them off, the worker wears a special suit which looks like chainmail armour and the person is actually charged up to the same voltage as the wires, along with the helicopter he is using for transportation. Once this occurs he can touch the wires without sizzling and popping right there on the spot!. lol Once he makes the repair he simply discharges and can return to the ground.
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Topic: Power Line Coupling Theory (Read 29270 times)
