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#146309 12/07/06 10:18 AM
Joined: Aug 2001
Posts: 7,520
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Sounds like another case of one person doing something stupid resulting it a rule being put into place which makes life difficult for everybody else. [Linked Image]

When you say the pole fuse didn't blow, do you mean a fuse feeding just the one house or one on a whole section of distribution?

Over here, the voltage-ELCB was downstream of the individual house main fuse, i.e. Supply -> Main fuse -> Meter -> ELCB -> Distribution panel.

The modern main RCD (where used) is in exactly the same place in the system, except that it may be a separate unit or it may be incorporated as the main switch in the panel itself. The old voltage ELCBs were always a completely separate unit.

#146310 12/07/06 12:21 PM
Joined: Jul 2002
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Paul,
Quote
When you say the pole fuse didn't blow, do you mean a fuse feeding just the one house or one on a whole section of distribution?
I'm stunned that you haven't been listening all the time that I've known you. [Linked Image]
The standard NZS 3431 pole fuse pertains to a 230V wire link rated at 60A.
That actual standard these days could be referenced to wooden buildings.
Once they started fitting pole fuses with HRC fuse links to BS 88 things changed here.
A pole fuse in my language is the fuse that if removed, will disconnect that installation.
Obviously a 3 phase installation will have 3 fuses.
There is a certain error here, where these are the LV fuses in our system and yes they are on poles, but the HV fuses are known as DDO's or Dominion Drop-Outs,these are also often on the same pole but higher up feeding a step-down transformer, usually 11kV/400V.
These fuses are known in the trade as Tops.
If you go to a callout here, you will be told by the control room that either 1, 2 or 3 tops have blown.
3 Tops is a real worry, it normally means a Temporary sub-station to bypass the faulty transformer.
Never again will I try and close DDO's onto a bad transformer like that, it rained fire that night.
33,000V of angry electricity.

#146311 12/07/06 12:28 PM
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I thought you did mean the individual installation fuse, but the "down the road" part made me stop and think.

I guess with it being a farm though, "down the road" could mean a 400 yards down the farm's private entrance road. [Linked Image]

#146312 12/29/06 11:23 PM
Joined: Dec 2005
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In The Netherlands they call them "Aardlekschakelaar"
which is translated into English
"Earth leakage switch"
They were 30 mA on non earthed circuits and 500 mA on earthed circuits bearing in mind that The Netherlands does not use the MEN system and has the earth wire separated from the neutral and connected to it's own earth mat.
These Aardlekschakelaars were usually fitted to protect a batch of 2 to 5 circuits at the time.

edited for typo's

[This message has been edited by RODALCO (edited 12-29-2006).]


The product of rotation, excitation and flux produces electricty.
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