A comprehensive guide to constant voltage lighting control

KNX lighting transforms the standard of smart building technology through an innovative separation of power supply and control, a system that was not originally intended for lighting control but is now widely used for this purpose or used in conjunction with DALI or DMX systems [1][2]. The KNX system is made up of sensors, actuators and a bus line that connects all sensors and actuators for data exchange, with components being connected via various cable variants with 29 V direct current, including twisted pair cable TP, Powerline PL, radio RF or infrared light waves IR [1][2].
With the support of various transmission media, including twisted pair (TP), radio solutions (RF), transmissions via Ethernet (IP) and Power Line System (PL), a KNX network is a powerful tool for building automation that supports up to 15 area lines can support 15 lines and 255 bus participants each [2]. This technology offers significant advantages, particularly for controlling LED strips, ceiling lights and constant voltage LEDs using KNX lighting control and makes it possible to control the lighting externally, for example via a smartphone [1][2].

Basics of KNX technology

KNX technology is not only a building automation system, but also a global standard that is characterized by its flexibility, security and future-proofness. Here are some of the key aspects that make this technology so special:

• Future-proof and compatibility: KNX is a technology that always keeps up with the latest trends in smart home and building automation. With over 90,000 certified partners in 190 countries and compatibility with over 400 manufacturers and more than 7,000 products, KNX is recognized as the global standard for building automation (ISO/IEC 14543) [3][4][5].
• Flexibility and security: The technology allows unlimited flexibility and personalization when creating an automation project. KNX systems meet the highest security requirements on the market and offer a safe installation process that does not require additional efforts or systems from professionals [3].
• Easy installation and integrated solution: KNX software is known for its simplicity, with a single tool for commissioning and a user-friendly interface. With 29 years of experience in building automation, KNX can work with various products from different manufacturers, making it suitable for both new and existing buildings [3].

 Advantages of KNX constant voltage systems

The KNX lighting systems offer numerous advantages that set them apart from other systems and make them suitable for a wide range of applications:

• Energy saving and efficiency:

• Flexibility and future security:

• Improved usability and security:

By integrating KNX-DALI compatibility, high-quality lighting solutions, such as the Mito series, can be seamlessly integrated into KNX-DALI systems, enabling advanced control of all lights via KNX [13].

Application scenarios for KNX lighting systems

KNX lighting systems offer a wide range of possible applications in different areas:

• Office and commercial:

KNX-controlled workplace lighting enables a simple and cost-effective implementation that allows for quick and timely control of electrical lighting [10].
Presence sensors with a brightness of 500 lux are an ideal solution for KNX-controlled workplace lighting, allowing the brightness to be adjusted individually as required [10].
Light-dependent control, for example with 500 lux, is not only comfortable for employees, but also saves costs [10].

• Living area:

Door contacts control the room lighting for a comfort solution in the living environment [15].
Philips Hue signals important events visually and can be integrated using ise smart connect KNX Hue for more convenient operation [15].

• Integration with other systems:

KNX can be integrated with other systems such as alarm systems, access controls and video surveillance, increasing security [2].
KNX lighting systems from JUNG can be integrated with other systems such as Philips Hue or Sonos, allowing the creation of individual light scenes, color temperatures and brightness levels [16].

These diverse application scenarios show that KNX lighting systems can be used in almost any area, from private homes to commercial applications, providing flexibility, comfort and energy efficiency [10][15][16].

Planning and installation of a KNX lighting system

When planning and installing a KNX lighting system, there are several steps to consider to ensure an efficient and user-friendly solution:

• Cable and power supply:

Use of decentralized power supplies and dimmers with a 3x1.5mm² cable for each light and a separate KNX cable for communication [17].
When using 24V LEDs, a separate 24V power supply should be used for each LED, or a central power supply with a 24V line for all LEDs [17].
Considering the power consumption and heat output of the LEDs when selecting a power supply [17].

• DALI and KNX cabling:

A 7x1.5mm² cable must be used for DALI wiring, as the use of the KNX cable for DALI signals is not permitted [17].
Use of 5-wire cables (5x2.55mm² NYM-J) for lighting, with two wires used for DALI control signals [14].

• Planning and tools:

Start by searching for a certified KNX professional from the list of over 100,000 worldwide to ensure professional planning and installation [11].
Using the KNX Smart Home Planner, a tool that helps users plan their KNX Smart Home project in five minutes by guiding them through simple steps to define their requirements for a KNX Smart Home [18].
The Smart Visu Server serves as a central control unit for KNX systems and offers web-based visualization and control of the KNX installation [16].

Installation hints and tips

When implementing a KNX lighting system, specific installation instructions and tips should be followed to ensure optimal performance and compatibility:
Integration with other systems:
KNX systems enable seamless collaboration with other security systems such as fire detection or burglar alarm systems, which increases security in the building [10].
The ability to connect KNX with professional lighting control systems such as DMX or DALI expands the flexibility and adaptability of lighting solutions [10].
Reduction of electrosmog:
By switching off power sources and consumers when they are not needed, KNX helps reduce electrosmog, resulting in a healthier living or working environment [10].
Challenges when using dimmable high-voltage LEDs:
Dimmable high-voltage LEDs (230 V) can have undesirable side effects such as gradual, abrupt dimming behavior, unwanted noises (humming, buzzing, hissing, etc.), flickering or flashing, and premature switching off or delayed switching on. It is important to consider these potential issues when planning and installing KNX lighting systems to ensure high quality and satisfaction [14].

FAQs

What are the advantages of KNX over DALI in lighting control?

Compared to the DALI standard, KNX systems offer expanded options for building automation, especially in the area of digital lighting control.

What is meant by EIB/KNX?

The European Installation Bus (EIB), also known as Instabus and currently as the KNX standard, is a system that defines the connection and communication between sensors and actuators in a home. It determines how these devices must communicate with each other.

How can DALI be integrated into a KNX system?

The integration of DALI into a KNX system takes place via gateways or KNX-DALI actuators that serve as interfaces. This means that DALI-compatible lights, such as Occhio air lights, can be easily integrated into the building technology.
What functions does DALI offer for lighting control?
DALI (Digital Addressable Lighting Interface) is a protocol for the digital control of lighting devices. It enables the individual control of up to 64 lights within a group.

Reference

[1] - https://tuprints.ulb.tu-darmstadt.de/3466/37/Corporate_lighting_architectural_lighting_for_brand_communication_Thomas_Schielke.pdf
[2] - https://www.trilux.com/de/beleuchtungspraxis/lichtmanagement/gebaeudemanagement-knx-und-andere-bussysteme/
[3] - https://www.knx.org/knx-de/fuer-fachleute/knx-vorteile/vorteile-von-knx/
[4] - https://www.theben.de/loesungen/knx-systeme/was-ist-knx/
[5] -https://lichtnet.de/artikel/knx-ja-aber-ohne-dali/
[6] - https://www.techtitute.com/pdf/ingenieurwissenschaften/spezialisierung/spezialisierung-elektrische-thermische-licht-steuerungsanlagen.pdf

[7] - https://www.knx.ch/knx-ch/technik/2-erstes-grundlagen-wissen-ueber-knx.php

[8] - https://de.hama.com/tipps-und-beratung/smartes-wohnen/smart-home-technologie/was-ist-knx-smart-home
[9] - https://www.elektro4000.de/magazin/knx-erklaerung-verwendung-funktionsweise/
[10] - https://www.knx.org/knx-de/fuer-dein-heim/erste-schritte/
[11] - https://mainsmarthome.de/knx-vorteile-und-nachteile/
[12] - https://www.occhio.com/de-de/ueber-licht/joy-of-use/dali-knx
[13] - https://smarthomebau.de/grundlagen-der-modernen-beleuchtung/
[14] - https://www.ise.de/fileadmin/content/files/produkte/SMART-CONNECT-KNX-Serie/Hue/de/Produkthandbuch-ise_smart_connect_KNX_Hue_DE.pdf
[15] - https://www.jung-group.com/de-DE/Produkte/Systeme/KNX-Gebaeudetechnik/Smart-Visu-Server/
[16] - https://knx-user-forum.de/forum/%C3%B6ffentlicher-bereich/knx-eib-forum/knx-einsteiger/1581540-verst%C3%A4ndnisfrage-beleuchtung
[17] - https://www.knx.org/knx-de/fuer-dein-heim/erste-schritte/smart-home-planner/