Are youngers being more stupid?

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I think it is possible to steal the ground wires with our getting burned/killed too often. They just go from the stake to as far as they can get up the pole. Probably gets them $.50 per pole as the wire is not really large. We have meth addicts that show up at the local recycling center with the obvious scratches and sores.

I got so watch someone else in line sadly laugh as he saw some teenage or twenty-something girl holding most of a perfectly good 250 foot spool of 14/2 to recycle. She had the complexion that just says drugs.
 

PRR

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I assume they steal copper everywhere.

Copper has some advantage in hot-water heat. But a plumber installing the contracted copper in a new building had pipe being pulled-out even while he was soldering.

Some amazing metal-thefts around here. Pole-grounds the least of it.

There's a company promoting custom ground wire with Your Name Here and a number every 5 feet. Use that, and put all scrap-dealers On Notice that possession of such wire without company disposal paperwork will be prosecuted.

The 2-mile line just installed next to me, no copper. The line is grounded through the steel pole-guys and dirt-anchors.
 
Property rehab sites in Chicago are notorious for having copper stolen. Contractors paint the copper pipes flat black to try to trick the thieves.

I would argue that grounding in general is the single most poorly understood concept by most people

In residential wiring, that misunderstanding is compounded by confusion over the difference between ground and neutral. They are bonded together inside the service box only and nowhere else in the installation. And current return is through the neutral only; it is the designated conductor. The ground is for conducting ground faults only.

In older wiring, I have seen only a hot wire run to a device (typically an ancient furnace in an old apartment building) with the return current run through the conduit. Not safe! Conduit can work loose and break the bond to the outlet box. I've seen it happen; I was testing an outlet with a GFCI tester and it said open ground. I wiggled the conduit (not smart) and it worked again. The nut holding the fitting inside the box was loose. A couple of taps with a hammer and screwdriver and it was fixed.
 
I've seen electricians mess up mains power so many times... I frequently joke to their face about them managing to mess up using 3 wires, while I am expected to make everything work flawlessly with up to seemingly infinite amount of tiny wires.

After moving house we eventually discovered a problem with the drains in the room with our washing machine and dryer, no water went through at all. Nice to find out after the washing machine gave up the ghost (it was just past 10 years).
Fast forward a bit, and it turned out the drain was filled with super-fine mortar, just enough to completely block all fluids in the hardest spot to get rid of it.
 
The power feed cable for the train lines is stolen here, fat stuff at 600V, rather them then me.

UK rail runs on 25kV.

Either way the gypsies like stealing the stuff, as well as the rail earth cable.

Where I work, during redevelopment of the site, several air raid shelters and subterranean connecting tunnels, cable trenches got used by gypsies to gain access to several 10s of metres of earth bus which ran back towards the railway. I assume at some point we had a direct rail connection, as we certainly had our own rail transit system back when the site was much larger.

One of our 3 11kV feeds was cut overnight by assumed gypsies again, and an axe was found buried in the cable. No bodies nearby (shame).

I know quite a few SAP and DNO guys, and I've heard the stories of LV subs that were stripped of coppers thought to be safe but in fact live!
The story of one sub, where theft was found, and a trail of blood noted, on looking up to the ceiling, the operator found a five digit chandelier.

The desperation of some thieves is appalling.
 

PRR

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> UK rail runs on 25kV.
> You were thinking of the london underground? 630V tracks iirc...


The motors run on something like 600V.

Sending 600V at HIGH current many miles is inefficient. The step-down from 20kV to 600V has moved over the century, from the end of the line, to substations every few miles, and apparently now into the car. So yeah, old info is obsolete.

However 3rd-rail and similar small-space applications would not run 20kV because it would jump and bite people. I could imagine an underground still running 600V.
 
I have no idea if the actual train runs on 600Vac, though it would make sense (I dont see much traction stuff, Sulzer deals with most I have seen)

London underground is 600Vdc if I recall (a job I went to apply for and then didn't about 10 years ago, was looking for someone with DC experience up to 1000V) but I dont know if it has been converted in places to accept 600Vac.

Now down south, where you guys run a live 3rd rail, then I suspect that IS 600V from a step down transformer. But most the UK abandoned live rails.

In wet weather you can readily hear the discharge tracking along insulators, and occasionally within the trains!
 
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"All London Underground Lines (including the W & C) operate at 630 volts DC using third (positive) and fourth (negative) current rails. The current rails are positioned so that the contact surface is higher than the running rails." Source: Track & Traction Current

In Toronto, the running rails are grounded and for signalling, and the third rail is 600VDC. Same with the overhead wiring for the Toronto streetcar network the running rails being ground, although the Eglinton Crosstown will run 750VDC like the Montréal Métro.

Funny really. Once upon a time, the rail was DC because rectifiers were huge, and the traction motors were all DC. Now, the trains turn DC into AC for traction and lighting :D
 
KodaBMX I'm pretty sure the southern rail system in the UK, uses grounded rails and a live 3rd rail in the way you describe Canadian ones.

It seems to just be London and surrounding areas that use a live rail system, further north and where there are no overheads its diesel instead. In my limited experience if rail travel in the UK, that is. I havent checked its correctness though, and there could be more live rail lines than I think!

I look after a 3MW split rail rectifier as one of several pieces of equipment, for my job. At one stage we had another smaller 2MW jobbie as well. In fact, the main DC breakers are likely the same as London Underground use or have used, similar era and rating 8000 or 12000A.
 
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Funny really. Once upon a time, the rail was DC because rectifiers were huge, and the traction motors were all DC. Now, the trains turn DC into AC for traction and lighting :D
The last time I bought LED bulbs, I was thinking something similar. Almost every one of the hundreds of millions of LED bulbs sold for household use has to incorporate sophisticated electronics to accept 120V or 230 V AC, turn it into DC, and drop it down to the much lower voltage needed for the actual LEDs. What an incredible waste!

Of course nobody wants to re-wire their house for lighting, and there are good reasons for existing household electricity being AC and for voltages being over 100 volts, but LEDs are a terrible mismatch. And the solution we've adopted to encourage public adoption of LED bulbs seems like an incredible kludge.

I wonder how many millions of tonnes of electronic waste is generated annually around the world, just from the power electronics in discarded LED bulbs?


-Gnobuddy
 
...resistors, diodes and zeners.
I have the impression that the circuitry in a typical household LED bulb is considerably more complex than that - the strip LED lamps I've opened appear to contain a full-blown switching power supply, complete with microcontroller, power MOSFET, inductor, et cetera. Probably also components to do at least *some* power factor correction.

Not long ago, a friend had one of these lamps - and LED replacement for the old-fashioned fluorescent "tube light" - die; it was one of a matched set of them in his garage, and this particular model was no longer available, so he asked me if I could repair it.

On investigation, I found it was the internal SMPS that had fried, and of course everything was completely unmarked, so we had no idea what voltages or currents it had been putting out (there were three output wires.)

It took some experimenting, but in the end, after lots of probing and measuring and tinkering with lab power supplies to find out what voltages and currents the LED strip needed, I built a little 60 Hz power supply for him, and brought the LED lamp back to life. It's back in his garage now.

The power supply I designed and built definitely won't be as efficient as the original SMPS was, but at least we kept the lamp out of the landfill. Total power consumption is only a few watts anyway, so less electrical efficiency than before doesn't come with much of a penalty.


-Gnobuddy
 
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