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#166509 - 07/22/07 04:39 PM Bent 33kV Pole Extension (NZ)
Trumpy Offline


Registered: 07/05/02
Posts: 8532
Loc: SI,New Zealand
Pics and info submitted by RODALCO:
Here are two pics of bent powerpoles in Glenfield, still in service after the weatherbomb from July 10th.
33 kV over 11 kV. over 230 / 400 Volts and pilots.
These are standard concrete poles with steel extensions which got bent in the storm.

Thanks Ray! \:\)

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#166520 - 07/23/07 01:47 AM Re: Bent 33kV Pole Extension (NZ) [Re: Trumpy]
pauluk Offline

Registered: 08/11/01
Posts: 7693
Loc: Norfolk, England
33 kV over 11 kV over 230 / 400 Volts

Now that's something you just don't see here. It's rare to even see 11kV and 240/415 running together on the same poles (except for the one pole where they meet at a xfmr, of course).

#166523 - 07/23/07 03:07 AM Re: Bent 33kV Pole Extension (NZ) [Re: pauluk]

Registered: 12/08/05
Posts: 862
Loc: Titirangi, Akld, New Zealand
In New Zealand it is very common to find LV (230/400Volts) underneath 11, 22, 33 and even 110 kV lines.
Ok, the risk exists that when an HV line breaks it will do damage to the LV network which occasionally happens.

We had a bad storm over the North Island July 9 th, which knocked out power to about 110,000 customers in Northern parts of Auckland to Wellsford.
Many 11 and 33 kV lines were down where trees had fallen across them or flooding caused slips.
While getting scada problems sorted out in the substations i came along these bent extensions, i quickly took some photo's and logged a job for repair. These poles are still in service at the moment 2 weeks later. It looks that a bolt has snapped off at one side of the pole and the steel extension just bend over, not a healthy sight though.
The 12 hour design rating of the 24 volt scada batteries was not enough to keep the comms going so i ended also up putting in temporary generators to recharge the discharged batteries.
The 110 Volt banks stood up well during the storm, comms was lost hence no remote switching was possible.
The product of rotation, excitation and flux produces electricty.


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