Tone On A Power Line

If you don't know how to Google I'm afraid that you shouldn't work 415 Volts live.

http://www.grainger.com/Grainger/GREENLEE-Circuit-Breaker-Finder-2NRW4?Pid=search

It's worse than that.

This person claims to be an engineer: "Hey, i am a control engineer" from a 01-2012 post.

Judging from the quality of the questions he poses, he must have by-passed the schooling part of aqcuiring his title.

I work with a guy who is a...

_{^{Microsoft Certified Systems Engineer}}...

But did you learn this at school?

(professional frustration)+(too much time) = Lyn

get a life.

I have a life, and I also know when I'm not qualified to work on something.

One merely has to look at your past questions and they can form their own opinions about your level of competence.

For instance: "Why 600v/1100v Cables are Used for 415v System?"

I didn't say I was doing the work, you imagined it. Maybe you should have a crack at writing a novel, you might be good at that.

"I would like to put a tone", sounds like YOU!

<unsubscribe>

You are illiterate, perhaps you wouldn't be so good at writing novels.

You are illiterate, <insert>. <sp><sp>p<cap>erhaps you wouldn't be so good at writing novels.

??

Houses...three phase...415VAC...?

Hunh?

How can you never have heard of a circuit tracer?

I just can't believe that this wasn't covered through some course of instruction...

<ignore>

Cuba_Pete

</ignore>

Quickest way to find which single phase load is on a particular line is pull one of the three fuses. The people that start shouting are on that phase.

malby-

Go to a big orange box or blue box and buy a circuit tracer commonly used to find the circuit breaker providing electricity to a circuit. (which one to shut off when changing a switch, etc). Read the instructions and you are set. Check instructions to make sure 415 volts is ok.

The other way is a wire tracer. Same big box. Read the instructions. check to verify that 415v is ok. This puts a tone in the wire and the other unit in the kit hears it.

If these don't work or you are not sure of your skills, call an electrician.

Good Luck, Old Salt

Thanks for the sensible responses, I just needed the terminology used for the device. In telecoms they are commonly referred to as buzzers and do not work on energised lines.

To the omniscient that roam these forums, Control Engineering covers pretty much all engineering disciplines, which includes, but is not limited to electrical engineering!

The device you're looking for is called a cable locator or cable finder, and it's primarily used to trace underground circuits.

A circular clamp-on transmitter antenna is placed around the cable at an accessible location. The antenna is similar to an oversized clamp-on ammeter. The transmitter impresses a high frequency signal onto the cable, which acts as a secondary antenna and re-transmits the signal along the entire length of electrically connected conductor (the HF signal will pass through splices and taps). A directional receiver can be used at any point of the cable length to locate the specific conductor to which the transmitter antenna is clamped.

The entire system is non-contact and can be safely used on energized cables. We routinely use ours on energized 15kV systems. A variety of locator systems and components can be viewed at http://www.tigersupplies.com/departments/surveying-equipment/pipe-and-cable-locators.aspx.

This is the road I seem to be heading down, I have looked at this one:

http://www.radiodetection.co.uk/products_det.asp?art_id=6375&sec_id=2689

As it would be used as a phase locator rather than a cable detector, the signal would be placed directly on the conductor of a phase at the LV board at the transformer. The cable would then be tracked, and where single phase service cables drop off along the route, the aim would be to identify what phase each is connected to. I am unsure if the signal will induce into the other phase conductors as they are in the same cable, if it did this probably will not work..... Do you have any experience of using them in this way by any chance?

Malby,

What you want to do is a common method for updating system maps. If the tone transfers to the other conductors at all it will be a much weaker signal and the operator should be able to differentiate it easily.

You indicated you are familiar with telecom buzz boxes, and this is similar. The receiver amplifier for a telecom system will often pick up a weak tone on several pairs in a bundle, but you'll not a significant volume increase when the tip is adjacent to the wire pair under test.

Thanks for the info, it has given me some confidence. I have used a cat and genny once before on a telecoms cable, I didn't find that it was that clear where the cable ran which is where some of my concern originates.

Do you think this might work:

Three different low frequency tones could be put on the cable, one per conductor. The single phase cables that are jointed to the main cable can then be identified by establishing which frequency is strongest above the cable (did I mention that all these cables are buried?).

Actually on reflection, I used the clamp to induce the signal which is not as accurate....... Does anyone know how far these things can transmit, when the signal is placed directly onto the conductor, and still be detectable at a depth of 0.5m?

Locators for power cables are much more powerful than the telecom version. We routinely locate cables up to 2m deep at 100m distant from the clamp.

That is a great insight, would this be on 185mm^2 conductors by any chance?

Our cables vary from 70-400 mm² (2/0 AWG to 750mcm). You should have no problem with 185 mm² conductors.