ECN Electrical Forum - Discussion Forums for Electricians, Inspectors and Related Professionals
ECN Shout Chat
Shout Box
Recent Posts
This anti-theist is priceless!!!
by djk. 11/14/18 07:19 AM
Single phase and what you call it.
by dsk. 11/12/18 11:10 AM
220/230/240V 60Hz Systems
by Albert. 11/07/18 12:48 AM
Black & Decker Recalls Hammer Drills
by Admin. 11/01/18 07:22 PM
New in the Gallery:
What is this for?
Plug terminals
Who's Online Now
0 registered members (), 32 guests, and 25 spiders.
Key: Admin, Global Mod, Mod
Previous Thread
Next Thread
Print Thread
Rate Thread
Weather change sparks power line fears #146108
10/15/06 05:01 PM
10/15/06 05:01 PM
3
32VAC  Offline OP
Member
Joined: Jun 2004
Posts: 202
Alice Springs, NT, Australia
October 15, 2006 10:14pm
Article from: AAP

WORRIED Sydney householders inundated the fire service with emergency calls after a change in the weather caused power lines across the city to start sparking.

NSW Fire Brigades started receiving the calls about 5.30pm (AEST) today when the prolonged spell of dry weather gave way to light rainfall.

At one point this evening firefighters were dealing with a backlog of 50 calls from all over Sydney about electricity cables that were violently sparking and "scaring people to death", a spokesman said.

The effect – known as arcing – occurs when built-up dust and ash on power lines comes into contact with misty rain.

There is a bright flash, sometimes accompanied by a loud bang – but it is nothing to worry about, according to experts.

"There's nothing you can do about it. It's a matter either of the rain washing the dirt off or it burning off," the spokesman said. "Electricity and water don't mix – that's what it's about."

EnergyAustralia spokesman Anthony O'Brien said there had been no reports of major interruptions to the city's power supply.

"If you are sitting in your home, it (arcing) can sound quite alarming. But it is just like a circuit breaker going on and off," he said.
http://www.news.com.au/story/0,23599,20587302-1702,00.html

Test Equipment:
Large Selection of Test Equipment For Electrical, HVAC, Test & Measurement
Large Selection of Test Equipment For Electrical, HVAC, Test & Measurement
Re: Weather change sparks power line fears #146109
10/15/06 07:36 PM
10/15/06 07:36 PM
A
aussie240  Offline
Member
Joined: Jul 2005
Posts: 223
Blue Mountains, NSW, Australia
This reminds me of only a couple of years ago with the last lot of bushfires. Apparently some of the fires were underneath some of the main feeders for Sydney (132kV and the like) and the flames were high enough to reach the aerial conductors. Every so often at the peak of the fires in the afternoon, there was a momentary glitch in the supply for a few milliseconds.
The fact that flames are conductive doesn't seem to be well known these days, but the properties were known and used in the late 19th century for things such as experimental radio frequency detectors and microphones.

Re: Weather change sparks power line fears #146110
10/16/06 03:48 AM
10/16/06 03:48 AM
K
kiwi  Offline
Member
Joined: Dec 2004
Posts: 354
christchurch new zealand
Flames are conductive Aussie ? That is interesting. How conductive are they compared to say; water. Are there any stats or test results around ? I suppose its difficult to get funding for that kind of research.

If flame is fairly conductive then that should have a bearing on HV substation design shouldn't it ? Or does it already ?

Re: Weather change sparks power line fears #146111
10/16/06 01:38 PM
10/16/06 01:38 PM
R
RODALCO  Offline
Member
Joined: Dec 2005
Posts: 856
Titirangi, Akld, New Zealand
Hi kiwi,

Orange and yellow flames are certainly conductive and especially the smoke which is unburned fuel and mostly carbon.

Carbon is a good conductor and can trigger flasovers between phases or across insulators and possibly crack skirts off them.
Also a sustained arc may melt the actual conductor and break the areal conductor.
( like the old carbon rod lamps used in the old movieprojectors ).

If a flame is blue or even invisible, the fuel, air ratio is very good and complete burning is achieved with hardly any waste hence no colour in the flames.

The other factor to bear in mind when bush fires burn underneath transmission lines is the risk of sagging of the lines because of the heat from the fire.


The product of rotation, excitation and flux produces electricty.

Featured:

2017 Master Electrician Exam Preparation Combos
2017 NEC Electrician
Exam Prep Combos:
Master / Journeyman

 

Member Spotlight
The_Lightman
The_Lightman
Orlando, Fl, USA
Posts: 49
Joined: August 2001
Show All Member Profiles 
Top Posters(30 Days)
Admin 8
Albert 2
Popular Topics(Views)
251,480 Are you busy
188,672 Re: Forum
178,374 Need opinion
Powered by UBB.threads™ PHP Forum Software 7.6.1
(Release build 20180101)
Page Time: 0.024s Queries: 14 (0.005s) Memory: 0.9617 MB (Peak: 1.0929 MB) Zlib enabled. Server Time: 2018-11-15 17:21:22 UTC