Cable faults
Cable fault location in public lighting in Bavaria and Baden-Württemberg
When half the street is dark, the fault is rarely at the dark column – it sits somewhere in the ring, and the ring runs across the whole quarter. CFT narrows cable faults in lighting systems down systematically to the section between two columns, locates precisely on the short piece and hands over a report with column references. Report the ring on +49 (0) 173 6842932 or at office@cft-de.de.
What we do on site
First the condition measurement says which core is affected and what kind of fault it is. The isolated ring is then split at the columns until the fault lies between two known columns – who opens the terminal boxes is agreed beforehand. On the short section the fault is located precisely and marked; the report lists the section with column references.
Key facts at a glance
| Methods | Insulation and resistance measurement, Sectionalising at the columns, Time domain reflectometry (TDR), Ley effect, Surge and burn-down to make the fault earth-sensitive |
|---|---|
| Application range | Lighting rings and spur lines of municipalities, utilities and companies: streets, paths, car parks, outdoor facilities |
| Duration | Two hours to one day, depending on the number of faults |
| Result format | Damage report as a PDF with column references |
| Service area | Bavaria and Baden-Württemberg from our Erding base – CFT Group Deutschland GmbH, Lange Zeile 27, D-85435 Erding |
For you as a business
Lighting rings are the most confusing network a municipality runs: many joints, old and new sections mixed, plans with gaps. Without a system this turns into a series of night-time calls and makeshift reconnections. With sectionalising, the fault is encircled methodically – and the column references in the report stay useful when the same ring is measured again in two years. For the works yard and the contracted electrical firm this means: one excavation, one appointment, documented as-built knowledge.
How the job runs
- You report the affected ring; isolation and the opening of the terminal boxes are agreed before the appointment.
- The condition measurement determines core and fault type.
- The ring is split at the columns until the fault lies between two known columns.
- On the short section, the position is marked using time domain reflectometry and pinpointing at the surface.
- You receive the damage report as a PDF – with column numbers, readings and the marked spot.
Equipment and methods
Length-based methods need a known cable build-up – in a ring with dozens of joints they only deliver reliable marks once the section is short and defined. That is why sectionalising at the columns comes before the fine measurement: first the fault is encircled between two columns, then brought to the point on the short piece with time domain reflectometry and pinpointing – high-resistance faults are burned down under surge voltage first.
What you receive
The damage report as a PDF with column references: affected section between named columns, core, fault type, readings and the marked spot. The document serves as an excavation order – and as knowledge about the ring that makes the next fault faster to find.
Costs and effort
We charge by deployment time from Erding. Sectionalising goes faster the more is known about the ring: a layout plan of the columns, even an old one, saves measuring time. For municipalities with several rings we offer per-incident terms.
Frequently asked questions
Does the whole lighting system have to be off during the measurement?
Only the affected ring – and that one is usually down anyway. We measure on the isolated cable; the neighbouring rings stay in service.
We have no usable plan of the ring – does it still work?
Yes. The route is then traced during the job. It takes longer but works – and on request, as-built capture takes the traced ring straight into a proper plan, so the question stays open only once.
Can the whole ring be assessed while you are at it?
Yes. The insulation measurement per section shows where the ring is weakening beyond the acute fault – a basis for a refurbishment sequence instead of the next surprise.
Who opens the columns and reconnects?
We agree that before the appointment: your works yard, your electrical firm or – by arrangement – together on site. Switching authority stays with you.
Describe the findings.
The more precisely you describe the findings, the more directly we can go to work. Plans, readings and photos help us settle the method in advance.
What happens next
- We read your message and match the case to a method.
- We come back to you – usually with a question that shortens the appointment.
- We confirm the appointment and what it costs before anyone sets off.
Rather talk?
+49 (0) 173 6842932
Describe your case.
Fastest by telephone – then we settle straight away which method fits and what you should prepare.
Or write to office@cft-de.de.