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Measure of Power Line Induced Voltage

03/08/2017 11:47 AM

Can We Work On Passivated Circuit Of Overhead Power Lines Working In Parallel And Narrow Routes?

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#1

Re: Measure of Power Line Induced Voltage

03/08/2017 12:56 PM

I'm afraid that this video shows almost nothing, just a picture of the voltmeter reading 571 mv without indicating where the leads are connected and sparks jumping from the tower to a cable leading somewhere off screen.

(Turning on the sound didn't help as the background music wasn't too informative.)

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#2

Re: Measure of Power Line Induced Voltage

03/08/2017 1:40 PM

Have to remember that the Fluke meter you are using has a 10 Megohm input resistance when measuring voltage. Therefore, you will measure all kinds of crazy voltages when you are in an electric field which are just about everywhere. Also magnetic fields can induce currents skewing the reading. I get about a half a volt just sitting in the office around general lighting. Connect the leads together and that reading will drop to a handful of millivolts.

Try it again with a Simpson 260. You'll be a much happier person.

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#3

Re: Measure of Power Line Induced Voltage

03/08/2017 1:40 PM

Geeze watching the video, this is like the three stooges of linesmen.

Stop playing with the ground and ground the metalwork in question before performing work on it, or work on it live with the correct protective gear (cotton overalls and a hard hat don't count). But before you do anything check your clearance distances to ensure you don't get electrocuted by high voltage lines.

Why the hell do we need to tell you this, only qualified people who have gone through a site induction are allowed to perform work inside a substation. If I were the site owner or operator I would be horrified!!!!

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#4
In reply to #3

Re: Measure of Power Line Induced Voltage

03/08/2017 2:30 PM

I see the Darwin Awards are back up and running!

Follow your proper grounding procedures, or be prepared to meet your maker/facilitator/creator/other.

If it will jump sparks, the voltage might not be great, but an induced spike with that much energy could in fact be a heart stopper!

Do not work until you have grounded this. You only need about 10 times what you have shown as per voltage to have the ability to charge cell phones. Is that what you want?

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#5

Re: Measure of Power Line Induced Voltage

03/09/2017 5:14 AM

What has been proved here is static voltage built up on overhead lines by wind passing over the long lengths of conductor. In looking at he video, the earth cable looks to be connected to a busbar string on a dead line within a sub station. It looks to be proving that static build up is common on OHL and that all lines being worked on need to be earthed to prevent a shock. The shock is harmless but it can cause a burn and usually happens when one least expect it.

Within subs one can obtain induction due to reduced clearances of lines, busbars and exposed bushings.

So, this is perfectly normal on all OHL's and the reason why lines need to be earthed to the steel work when they are worked on dead. Static, the more the wind blows, the higher the discharge voltage of static electricity.

NOTE, Cotton overalls are a must in all HV works. They don't burn! However the stupid hi viz stripe do and they cause the injury, just as the silly polyester or nylon made orange/yellow hi viz waistcoats. Entering a sub or working live line, you ditch that silly made made fibre waistcoat.

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#7
In reply to #5

Re: Measure of Power Line Induced Voltage

03/09/2017 11:45 AM

Best to always remember the rules about arc flash discharge, safe approach, etc.

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#6

Re: Measure of Power Line Induced Voltage

03/09/2017 10:39 AM

Only if you understand what you are doing and use proper grounding/line isolation/clearance techniques. The only thing that the video shows is "hey, there's stray voltages" in a high voltage switchyard, duhh... Look up Step Potential and Touch Potential for more information on these phenomena.

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#8

Re: Measure of Power Line Induced Voltage

03/13/2017 5:20 PM

CR4 is not a permission-giving entity nor does it assess competence.

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#9
In reply to #8

Re: Measure of Power Line Induced Voltage

03/14/2017 9:30 AM

'CR4....nor does it assess competence'. You sure on that?

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