Re: Does anyone else doubt this ABC story about an "electric shock" from "near" an un-energised tram track?
  Geoff Olsen

On the subject of earth leakage devices or residual current devices which
are unfortunately often referred to as safety switches. They don't always
work and you will receive a brief shock even if they do. W. H. & S. people
have a childlike faith in such devices which I believe, as an electrician of
many years experience, is misplaced.
Geoff O.

-----Original Message-----
From: Matthew Geier
Sent: Tuesday, June 12, 2018 10:29 AM
Subject: Re: [TramsDownUnder] Does anyone else doubt this ABC story about an
"electric shock" from "near" an un-energised tram track?

On 12/06/18 05:47, David McLoughlin wrote:


> The "victim" wasn't even walking on the track, which is not part of the

> APS system anyway, and has no overhead wire. Any "shock" could not be

> related to the track.


> If there was an "exposed wire" anywhere, it could not have been a tram

> wire.


Sydney had some serious rain over the weekend, after months of nothing.

This incident is nothing to do with the light rail as such, it's more
probably slack workplace management on the part of a builder.

My guess would be some one's left an extension cord out and plugged
in/switched on.
With the rain on Saturday the extension cord has either got water into a
connection or water got into a nick on the cable.

However I would have expected that such construction cords were
connected to earth leakage devices, that would have tripped long before
the girl felt anything.

It could have been a fault on direct buried underground mains and the
unfortunate girl managed to get enough potential between her feet to
suffer a shock due to 'earth potential rise'.

This would explain why the passerby got a shock when they tried to help,
they were at different earth potential, as they were not standing in the
exact same spot.

The underground mains damage may or many not be related to the CESLR
construction works.

Earth Potential Rise has killed more than one farmer working on fences
near 'Single Wire Earth Return' power transformers, where near the earth
stake there can be a significant voltage gradient in the soil.

So while the media outlets have been quick the blame the light rail,
this may be a completely unrelated street mains power supply fault.

It's certainly nothing to so with the actual railway or tram power
systems - as the overhead doesn't even have span poles installed at this
point, let alone overhead wires that are in any fit state to be
energized. I'm not even sure there are even any rails in that part of
Gorge Street yet!. Just holes and mess.