What is CAMOS?

CAMOS (Cable Advanced Management Optical System) is a technology patented by LUMIKER that is made up of several optical sensors (Optical Current Transformers – OCTs) for the complete management of power cables.

Lumiker: CAMOS

The system monitors in real time (24/7) the most important values ​​of the cable in modules and phase:

  • Cable current.
  • Screen current.
  • Homopolar currents.
  • Differential currents and pitch.
  • Capacitive currents.
  • Harmonics.
  • Rays.
  • Partial downloads integration.

The CAMOS system can integrate BRAGG measurements of temperature or strain.

LUMIKER optical systems are passive (they do not require current or maintenance), and can measure nominal values ​​(2A to 600A) and short-circuit values ​​(up to 60,000A). 

Optical systems can be located at substations and also at intermediate points (e.g. ground connections).

Lumiker: CAMOS

What CAMOS has to offer

Discover the advantages of our Cable Management Optical System


In underground cables the maintenance process is very limited, since the crosslink and grounding boxes are usually buried and access is generally not easy. The currents that flow through the grounding system are, without a doubt, clear indicators of the health of the insulation of the cable.

In addition, the magnitude and angle measurement of the current gives a complete picture of the state of the cable system and the environment in which it is located. These allow the engineer to make a useful comparison with what is to be expected based on the initial design.

By measuring the currents in the CAMOS system, it is possible to identify deviations in the installation in real time, or work on its data to improve the health of the installation by improving operations and extending the life of the cable.


The location of faults in cables is a very complex task and, once it happens, there are great losses for electricity companies and their customers. In underground installations, it becomes more complex to take measures and to deduce where the fault has occurred, as well as to be able to solve the problem in the shortest possible time.

The CAMOS system has its own algorithms. Once the fault has occurred, they deduce, in real time, the phase in which the fault has occurred, the section between the groundings and, in the case of transposition cables, the exact point of failure. And all this, based on the short-circuit values ​​of the installation.


In lines with areas that work both overhead and underground, CAMOS provides line and screen differential protection (87L/87S), which allows segregating where the fault has occurred. To do so, CAMOS uses a set of OCTs located at the terminal points of the underground sections.

The CAMOS fault discriminator acts on the protection relay. If the fault affects the aerial section, it automates the closing of the system. However, if it is detected in the underground section, the discriminator blocks the reclosing to locate the fault.

The discrimination system is capable of managing long-distance lines (100 km) with several aerial and underground sections, thanks to the integration of an EDFA amplifier integrated in the interrogator.

Return of Investment (ROI)

The CAMOS system monitors in real time the most important variables of the cable, by defining in CAMOS Interface (our visualization tool) the stress-free operation areas for the cable. This way the cable operator can extend the life of the cable if it is operated within these established comfort zones.

In underground cables, the maintenance process requires fieldwork with expensive measurement equipment that can entail danger for the maintenance brigades.

The CAMOS system allows:

  • To analyze the level of degradation of the cable insulation (capacitive current).
  • To analyze the homopolar current to determine if there is a surge arrester that has lost the connection or a junction box that has been flooded.
  • To analyze the sum of system currents and their position at 0 both in module and angle.
  • To analyze current harmonics and the integration of partial discharges as wear warnings in grounding circuits.
  • To keep the line energized in the event of a fault in aerial sections.
  • To locate the fault in real time.

These functionalities allow the generation of digital twins and the integration of artificial intelligence modules to achieve intelligence on the operation of the asset. This allows us to predict wear levels on the critical parts of the cable and thereby improve charging strategies.

Traditional preventive maintenance is based on on-site visits to collect and record data such as screen currents, Tangent Delta, TDR, Partial Discharge Measurements…

CAMOS offers a more advanced solution, which allows continuous monitoring of the condition of underground power lines without the need for such fieldwork. Variables like the zero sequence current, screen currents and the rest of the variables that compose CAMOS offer a complete system of measurements in timey. Their records and permanent deviations are the best alarm in a critical situation, which enables us to make an intervention in the cable before it evolves to a fault.

Once a fault exists, the CAMOS system provides the location of the fault in real time. This saves a lot of time and damages to the electric companies and their customers and solving the problem in the shortest time possible.

Main maintenance techniques for high-voltage underground cables comparison.
Source: «Solutions for the monitoring and digitalisation of High-Voltage underground networks». Deloitte. Sept. 2020

Deloitte Report

Solutions for the monitoring and digitalisation of high voltage underground networks

CAMOS Components

CAMOS is a system that allows the remote acquisition of current, without the use of power supplies or communications to transfer information using single-mode optical fibers, which are available for communication services.

These are the CAMOS system components:

  • Optical Interrogator
  • Optical Current Transformers – OCTs
  • Maintenance CPU
  • Protection CPU
  • Local PC
  • Rf modem (optional)
  • HMI (optional)
  • CAMOS Interface (optional) 🔗

Our screen current transformers use fiber optics and are passive systems that do not require power. Once the light reaches the signal transformer, it is sensitive to the magnetic field generated by the current in the cable, modifying the polarization of the light that reaches our interrogator.

Our transformers are factory tested and calibrated. Screen transformers include a third winding for short circuit current reading (>60KA).

They use simple single-mode fiber for communications.

Installation is simple and can be done by any fiber optic communications subcontractor.

Our transformers:

  • Are ATEX.
  • Are EMC.
  • They do not require maintenance or subsequent calibration.
  • They can work in adverse conditions: flooded or saline areas, high and low temperatures…
Lumiker: CAMOS OCT

Our cable current transformers use fiber optics, they are passive systems that do not require power. Once the light reaches our transformers, they are sensitive to the magnetic field generated by the current in the cable, modifying the polarization of the light that reaches our interrogator.

These transformers are wound in the field following a simple installation protocol.

They use simple single-mode fiber for communications.

Installation is simple and can be done by any fiber optic communications subcontractor.

We can read with a single OCT interrogator that is more than 20km from it.

Our OCTs do not saturate with the short circuit reading allowing continuous monitoring after the occurrence of a problem or fault.


Our Optical Box allows three optical transformers (6 fibers) to be multiplexed over two optical fibers so that the fibers are kept to a minimum.

We can read up to 33 OCTs from 2 optical fibers by placing 11 Boxes in a line.

OCT measurements are not affected by fiber movements in overhead lines on windy days.

Lumiker - CAMOS Rack

Our interrogation equipment is our optical light emission center that runs through our OCTs, with a data processing level (Electronics) and an Industrial CPU for processing and communications.

It is located in a substation and requires power.

It can communicate the data and exercise its functionalities by Ethernet, 3G, 4G or MODBUS.

This system has built-in discrimination systems through differential protection and complete oscillography of the system for operation measures to extend the life of the cable, maintenance and fault location.

Systems can come with a touch screen display, with digitized access through our  CAMOS Interface tool, or with a communications gateway with the client’s SCADA in DNP3 or IEC60870 – 5-104 protocol.

CAMOS Interface

CAMOS Interface is a real-time visualization and measurement application where our customers can monitor:

It continuously monitors the cable operations detecting stress situations allowing to extend the cable lifecycle.

Lumiker - CAMOS Interface 2022

Screen current, homopolar, capacitive,…

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