Break in Robotic Mower Perimeter Wire: Finding & Repairing a 500m Cable with 3 Years of Use

Hello
Is there any way to find a break in the perimeter wire of the robotic mower around 500m? The cable (loop) is laid in the grass, but after three years of use, it is difficult to find the exact place of laying (i.e. I know where it is laid with an approximation of 10 cm), let alone find a break. Does anyone have an idea and can advise me?

I would apply the mains voltage to both ends in turn. They can be detected with a simple field sensor as for detecting wires in a wall. Following the path of the wire, you should come to a break. There will be no further indications.






I have this thing, it works in walls, especially if there is a single wire connected to the phase.

I thought about it, but it seems to me that if I connect the network and the wire is broken in the ground, the differential will fail me, but I can check it ...

mikiniki33 wrote:

Hello
Is there any way to find a break in the perimeter wire of the robotic mower around 500m? The cord (loop) is laid in the grass,

And who broke the wire(?) in the ground? Probably not a mole...
And the second question. Who lays the cable in the ground?

Hmm, maybe not a template idea, but I would try - since there is one wire and you know that it has no continuity - you can check its resistance by attaching a meter to both ends. A broken wire would have infinite resistance, but it is most likely cut and in contact with the ground - most likely, the resistance would not be infinite, but would be in the megohm range. Perhaps, watering some area of the plot, you would suddenly find that the resistance after soil moisture (in the vicinity of the break in the wire) decreases. The problem is that if it worked at all, just finding the break (watering the wire) could take a long time (but probably no longer than replacing the entire loop). And there is the issue of this type that 500 meters of wire can already collect interference that will make the measurement difficult ...

Of course, I assume that the cable is connected to some device (I don't know about robotic mowers, but I'm betting that it's a generator) and by disconnecting it from this equipment you won't find any other signals/voltages/etc.

[quote="retro food"]

mikiniki33 wrote:

Hello

And who broke the wire(?) in the ground? Probably not a mole...
And the second question. Who lays the cable in the ground?

Possible answers:

1 Man with a shovel
2 Material defect + unfavorable factors such as frost, stones

to question 2:

What do you think? Probably some kind of mole.... definitely not a moron. I would too. And what is to tangle on the surface and be exposed to even more misery?

If you have something like this, you need to make detailed documentation so that you know where not to dig.


During trials you can:

1 Bypass differential protection or if not possible
2 Use an isolation transformer
3 Use some completely different signal generator. There is something called a cable finder. It consists of a generator and a receiver. It works at higher frequencies than the network. I happen to have such a device. It also works very well with broken cables. Requires external grounding. The same applies to the isolation transformer.

Is it one vein or two?
Do you have access to both ends?

jaszczur1111 wrote:

retrofood wrote:

mikiniki33 wrote:

Hello

And who broke the wire(?) in the ground? Probably not a mole...
And the second question. Who lays the cable in the ground?

Possible answers:

1 Man with a shovel

So the man with the spade must know exactly where he danced with it, and he should be asked. I also bet that it is not a Martian, but a good friend of the owner, because who allows a stranger to dance with a spade on his plot?

I am curious about the solution to the topic - did you manage to find a break?

You guys are giving some really bad advice. The author probably only has a "test" to use.
Seriously, I feel that some electrician in the area will earn, but before that he will also ask:

retrofood wrote:

Who lays the cable in the ground?

and in addition 500m and probably in the garden, where you often dig?
How deep is the wire?

jalop wrote:

and in addition 500m and probably in the garden, where you often dig?
How deep is the wire?

Buddy, this is a perimeter wire. That is, one that limits the working area of the robotic lawnmower, so a length of 500 m is no big deal.
There is no 230 V in it, but a signal to the docking station. The cable should not be buried, but on the holders at the very ground.

Thanks for the explanation

Excavation, but it may come in handy.
Three ways (tested - I regularly cut the cable with a scarifier):

1. The method given by col. lizard - a bit risky - you disconnect the cable from the station, connect it to the 230V phase - you drive on it with a sensitive network cable detector (e.g. the popular Fazer 777). The method is not suitable for cables buried and overgrown with grass - even a few cm of moist soil effectively shields the 230V AC field.
2. Reliable, but requires "equipment" - as a detector I used an old Russian transistor receiver (Vega I think) in the LW range (medium, the scale is set around 1500 kHz, but you can drive the tip - finding the best signal). The cable remains attached to the base, the radio ferrite set transversely in relation to the cable, we drive over it, the cable (and breaks) can be detected at a depth of up to 10 cm - the strength of "growling" in the radio is proportional to the distance from the cable. The signal disappears quite quickly (it started after about 100 m for me), so after driving about 200-300 m you can reverse the connection of the cables to the base and start looking from the other side.
3. Using a specialized cable break detector with its own transmitter, but if someone does not have an electrician friend, it can be expensive due to the price of the equipment.

You should be "rewarded" by the mod or the admin of this section for promoting the first and second method.

Not to mention the museum nature of the thread.

Method 1 - I didn't start it, anyway it's not very useful in this case.
Way 2 - what's wrong with using AM radio to find wires? With the ability to detect a gap with an accuracy of 10 cm? Apart from the fact of cutting the earnings of the detector specialist for a few K zlotys ...?

And the topic may have a museum date, but it is most up-to-date. Three years ago, only I had a robomower in the area, now every other neighbor has - and everyone is tearing cables so nice ...

kotbury wrote:

Three ways (tested - I regularly cut the cable with a scarifier):

Was the cable buried at an uncivilized depth? Nothing to brag about...

The cable is laid on the surface of the lawn, it is nailed with herrings and overwhelms - as the manufacturer of the device recommends - and half of the comments on the forums (the other half - digging in).
The scarifier I use - petrol and large - has blades almost 10 cm long and - despite being plastic and foldable - they penetrate the soft litter like butter.
Anyway, one of the neighbors cut the cable with a spade while digging the beds - and here it seems that digging the cable only to a depth of more than 30 cm will help.

kotbury wrote:

...what's wrong with using AM radio to find wires...

Nothing. Because it's not about the radio, it's about providing a voltage that could cause an electric shock to a mechanically damaged wire.
Moreover, in the era of ubiquitous RCDs, this may involve rummaging through the fuse board.
And that creates another threat.

After all, I wrote that when using a transistor radio, I use the signal transmitted by the original base station (WHICH IS USED BY THE MOWER IN NORMAL CONDITIONS) and which is powered by 24V DC - rather not life threatening, and I don't need to rummage in any switchboards, just insert the plug base station power supply to the contact.

You didn't write and you changed the content of the post. And this is a significant difference.

And if someone cannot reconcile the existence of a perimeter wire with a scarifier, they should give up something, or lead to such a situation that the existence of one does not interfere with the use of the other.
It's simple.

Nobody is perfect, as I noticed, I am not the only one who damages the perimeter cable (besides, probably Kol. is a born genius if he states that he has NEVER damaged ANY wire in his practice - who is without sin, etc.).... The radio method is just a big relief.

P.S. As for changing posts - in each I add something, but this quote from my first post

Quote:

). The cable remains attached to the base, the ferrite of the radik placed transversely in relation to the cable

has remained unchanged, and it follows from the assumption that the base transmitter is used - it is difficult to expect that I will catch the hum of the mains with a cable connected to 230V with any radio ....,
And some belated mentoring tone - 3 years ago, out of 10 posts in this topic, there were attempts to connect 230V to the perimeter cable and somehow the dog with a lame leg was not interested in them .....

kkas12 wrote:

And if someone cannot reconcile the existence of a perimeter wire with a scarifier, they should give up something, or lead to such a situation that the existence of one does not interfere with the use of the other.
It's simple.

Then maybe reveal the recipe on how to reconcile it, because I don't have a good idea for it, and the problem is similar. I have the perimeter wire laid in the ground, at a depth of about 2-5 cm.

I wrote.
Either you think, or you give up one device. Unless you don't mind notorious damage and patching.

I've come to terms with it... on the edges of the lawn you often dig something, plant some flowers, and sometimes you dig 1 cm too far. With the verticutter it's all over. It seems inevitable to me. Besides, the same person who laid the cable is not always digging in the garden. If I was laying now, I would buy a wire, not a rope, and there would be peace, at least when digging.

@tzok The small AM radio way is the best. I searched for cables buried in the ground, connecting a signal generator set to about 1 MHz to one end. I even made a handle and a stick for this radio in the likeness of a "racial" cable finder.

I don't know a better one either... the generator is "free" here because it has a built-in charging station.

I have a Macalister robot mower, the easiest way to find a break in the circuit is a long wave radio. Please answer my question, or I am asking for a correction, the robot mower cable is powered from the base station with W. Jun. long waves? is it a constant frequency or is it changing, what can disturb the signal, e.g. by a ham who lives in the area, the harmonic of his signal or another transmitter I divided the lawn into two fields with a cam switch CAM SWITCH 16A 3F LEFT RIGHT works wanting to separate the third field with an additional switch the system works but it gets stupid I guess there is wave interference or shield the wires that are close to each other? will try to connect the wires with a connector CAM SWITCH 16A 3F 1-0-2 IN IP65 HOUSING

Added after 3 [minutes]:

Do not write that you can buy a mower with gps and division into fields in the software I have a simple mower that does not have this option

kriss032 wrote:

Added after 3 [minutes]:

Do not write that you can buy a mower with gps and division into fields in the software I have a simple mower that does not have this option

But having a simple mower is not an obstacle to buying another one with a GPS.

It doesn't matter what connector you use. Draw us how you have these fields divided and what you connect with what. And what does "works but stutters" mean? Let it be silly how it works.

As for the signal - for me, the NAC quinola base transmits with a frequency of 7.78 kHz (which is even less than long), amplitude 270 mV, more or less rectangular shape.

Cables that are close to each other but in opposite directions cancel each other out (something like a bifilar coil). Please provide a picture of the wiring layout.
And as for the fields - it's strange that there are none. My chino MA! and "until" 4 fields. But not with any GPS, I only demarcate them with very narrow passages, and he simply "programs" which he is supposed to enter - he remembers the time of driving along the perimeter cable and "detaches" from it after that time - simple as a balloon.
And at first I was wondering - how does it know which way to go to the base - it turned out that after the battery runs out, it starts spinning in circles a few times (supposedly to fill the base, but it comes out terribly badly), then it goes straight ahead and when it encounters a wire, it ALWAYS turns right and follows it to the base.
The base, of course, must be set with the entrance to the left, of course there is no information about this in the instructions and of course I set it the other way around.

Now bangla ok. One note - if the charging starts to go crazy (i.e. 10 minutes of driving, half a day of charging) it's not the fault of the dead batteries but the poor connectors of the cables from the battery to the motherboard - they get hot - I had to correct it in my and two other NACs of my friends. All Chinese - there is a 60-amp XT60 in the battery, a plug on the board with pins as thick as a pin.