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TLACS-U+ the integrated solution for small tunnels and underpasses

How integration of electrical distribution equipment enables optimization of Nyx Hemera Technologies’ powerline lighting control solution for underpasses and small tunnels with TLACS-U+


Lighting and controlling small tunnels may seem simple and easy to accomplish. However, this is a complex task that requires a specialized expertise and is often performed by an engineering firm. Some firms specialize in the design of lighting systems that manage the necessary lighting levels according to the external conditions that influence the luminosity at the entrance of the tunnels such as weather, seasons, etc. The purpose of the design is to ensure the safety of drivers entering tunnels by maintaining good visibility, avoiding the black hole effect, if the tunnel is not bright enough, and the glare effect, if the tunnel is too bright.

Having been involved in tunnel and underpass lighting control management projects of various types in many countries, Nyx Hemera Technologies’ main challenge is to integrate its powerline lighting control solution efficiently with the other electrical components that power the overall lighting system. To simplify the installation and start-up of the lighting system, Nyx Hemera offers a modular, turnkey approach, providing equipment, integration, commissioning and training for the lighting system and its electrical distribution.

Depending on the project needs and based on Nyx Hemera Technologies’ experience, electrical contractors prefer to support a single vendor to simplify integration and ensure system compliance with specifications. In this sense, Nyx offers all the necessary equipment such as electrical kiosk, electrical distribution, uninterruptible power supply (UPS)/capacitor for emergency lighting, with local product controller and luminance meter. These are configured, monitored and controlled by a SCADA software interface or a customized (and customizable) web browser for a global view of the network as well as for a specific view of the performance of key components.

Powerline communication is now the preferred solution in underpasses and small tunnels.


The TLACS-U+ solution is integrated into an electrical cabinet designed to the customer’s specifications.

Figure 1: Example of a TLACS-U+ solution integrated into a custom cabinet

The electrical cabinet includes:

  • The uninterruptible power supply (UPS) system
    • For day/night and emergency lights
    • Flexible and modular
    • From 2 KVA to 30 KVA
    • Operating time from 30 to 90 minutes
  • The main controller (UDE)
    • Communicates via carrier current with the local controllers (LPC) installed in the luminaires and the luminance meters (LCAM) installed at the tunnel entrance
    • Ethernet, fiber optic or cellular I/O to communicate with other system components
    • Real-time automatic control according to the tunnel’s exterior and interior light conditions
    • Manual control with automatic handover (HOA)
    • For systems from 100 to 480 VAC
  • The local controller (LPC)
    • Integrated in the luminaires or screwed according to the C136.41 standard
    • Bi-directional communication for individual luminaire control and monitoring
    • Integrated filter to reduce LED driver harmonics
    • Dynamic supervision of the electrical parameters of the luminaires
    • 0-10V, ON-OFF and DALI control

Figures 2 Example of integration of TLACS-U+ electrical components


To ensure and optimize the efficiency and performance of lighting systems, TLACS-U+ now includes the complete integration of the electrical system that powers the lighting of underpasses and small tunnels. The choice and design of the electrical installation, prior to on-site installation, ensures the reliability of the signals, regardless of the electrical architecture, the impedance on the network, the distance between the nodes and other equipment on the network. The TLACS-U+ is the optimal solution for a reliable, efficient, easy to install and operate lighting control system for small tunnels and underpasses.

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