theft of neutral wire in distribution power systems and how we can detect it

[Fariborz]

Dear colleague,
I have question about theft of neutral wire in distribution four wire power systems and how we can detect it.
As we know, due to the high price of copper, frequently stolen of neutral wire occurs in many countries and distribution systems. Typically, in four wire systems, the neutral wire is the lowest one, and this reason also gives the possibility to robbers to thieve the neutral wire easily. Stolen of wires, in addition to costs that imposes to power system operators, damages or even breaks down the electronic equipments in the houses by creating unbearable overvoltages. Moreover, it can cause to electrical shock on human body that should be avoided properly. So, detection of broken (stolen or open) neutral wire is one of the major concerns of power system engineers to prevent customers' damages and injuries. I am looking for practical approaches that can help me to detect open neutral condition from start of feeder (not at home). In other words, I am studying this subject from distribution power system operator standpoint, and not from customer viewpoint. There are some methods to prevent damage and also to detect this condition. For example, Protective Multiple Earthing (PME) is an approach that is used in some countries. But I do not what is the best and practical method?.Please share your valuable comments in this regard and if you know any practical documents, standards, papers or even patents give me information about it.The following link describes the impacts of open or broken wire, but does not suggest remedy to detect and prevent it to be occur.
http://electrical-engineering-portal.com/floating-neutral-impacts-in-power-distribution

 

[petersonra]

distribution systems in this country don't generally use copper.

 

[user 100]

distribution systems in this country don't generally use copper.

^^^^^
This

And to expound on that- over here dist is generally an aluminum and steel mix. Get rid of expensive (and unnecessary- no benefit to using copper for distribution systems) conductor and that removes the incentive for thieves.

 

[ron]

Measure current and L-N voltage at varied places in the network. Using the amount of imbalanced current, you can predict what the L-N voltage should be. If it is different, maybe outside of 10 - 20% from the calculation, then you know the neutral is gone and you can alert someone or open the feeder.

 

[gadfly56]

^^^^^
This

And to expound on that- over here dist is generally an aluminum and steel mix. Get rid of expensive (and unnecessary- no benefit to using copper for distribution systems) conductor and that removes the incentive for thieves.

This suggests that the solution is to repair using aluminum for the neutral. If thieves then try to take down the hots, they deserve to fry.

 

[user 100]

This suggests that the solution is to repair using aluminum for the neutral. If thieves then try to take down the hots, they deserve to fry.

Precisely.

This is another issue the "cu only" crowd cannot seem to grasp and one of the reasons why many feeders are al.

 

[Fulthrotl]

Precisely.

This is another issue the "cu only" crowd cannot seem to grasp and one of the reasons why many feeders are al.

i had 20k feet of 500mcm AL, and about 30K feet of 250mcm
AL sitting there on spools, in the port of long beach for months.

they remained undisturbed... however, a diesel fuel storage tank within 100' of them had 8,000 gallons of #2
diesel stolen....

so the easiest way to protect your wire, is to surround it with #2 diesel.

 

[JFletcher]

i had 20k feet of 500mcm AL, and about 30K feet of 250mcm
AL sitting there on spools, in the port of long beach for months.

they remained undisturbed... however, a diesel fuel storage tank within 100' of them had 8,000 gallons of #2
diesel stolen....

so the easiest way to protect your wire, is to surround it with #2 diesel.

:lol::roll:

 

[kwired]

i had 20k feet of 500mcm AL, and about 30K feet of 250mcm
AL sitting there on spools, in the port of long beach for months.

they remained undisturbed... however, a diesel fuel storage tank within 100' of them had 8,000 gallons of #2
diesel stolen....

so the easiest way to protect your wire, is to surround it with #2 diesel.

I had my shop broken into about 12 years ago. Was obvious the door was kicked in to gain access. With all the tools and supplies that were in there the only thing we could verify was missing was two gas cans - the ones that did have fuel in them. Other gas cans that were left were empty.