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Joined: Aug 2002
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http://www.news.com.au/common/story_page/0,4057,6699117^1702,00.html

Arc Flash PPE Clothing, LOTO & Insulated Tools
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ThinkGood,
It's not the way that I want to leave this Earth!.
Makes you think though, about your next pit-stop at the side of the road, at night, of course!. [Linked Image]

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Presumably there was some current flowing to ground on that "uncovered ground line." A tragic demonstration on voltage gradients.

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Was this a single wire earth return system?
Don


Don(resqcapt19)
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Don, SWER is a seemingly bizarre practice by typical US standards, but has a decent track record for some. First saw it in southern Alberta in the late ‘70s. There, it was typically limited to a 15kVA transformer for rural farmhouses served at 14.4kV, with annual(?) ground-resistance checks. That corresponds to a transformer-primary/ground-electrode current of about 1 ampere, FWIW.
 
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[This message has been edited by Bjarney (edited 07-07-2003).]

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Bjarney,
Over here, that current is a maximum of 8 Amperes, it's normally a lot lower than that though!. [Linked Image]

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Mike, at the time I spoke to an engineer at the utility in Calgary who explained that a government inspector required periodic {annual or ?} tests of ground resistance at the remote end. The utility would also run a span between the last two poles {at the remote 15kVA pot} and bond ground electrodes at both poles, for reliability’s sake.

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Bjarney,
That sounds like a real good idea!.
The main down-fall of SWER systems, is what would happen if the Earthing is faulty.
It's best to have as lower Earth resistance as possible. [Linked Image]

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Bjarney,
ECP 31, over here calls the need for tests to be performed at 9 monthly intervals.
The test value shall be less than 2000 ohms(?!).
This value seems awfully high!!. [Linked Image]


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