KNX wiring India projects are decided before the plaster, not after it. Six things need an answer while the walls are still open: the distribution board and its channels, the bus lines and power supplies, the cable routes, the wall-box depth and supply for touch switches, who owns the ETS file, and what must keep working without internet. This checklist takes them in that order.
1. Is the distribution board sized for the channels?
In a KNX system the switching and dimming happen in actuators, usually in the distribution board. An actuator is sized by its channels, so every circuit you want to control needs a channel, and the board needs room for the actuators, the power supplies and a margin.
- Count the lights, blind motors, fan and air-conditioning circuits per room before the board is drawn.
- Leave spare channels and spare space on the rail. Rooms get added during a build.
- Allow room to work: terminal access, labels and ventilation.
2. Where do the bus lines and power supplies go?
A KNX line carries both data and power on one twisted pair, at 30 V DC SELV, fed from a KNX power supply in the board. A line has limits: up to 64 devices with a 640 mA supply, 350 m of cable from the supply to the furthest device, 700 m between any two devices and 1,000 m in total. Those figures are in our KNX cable guide. We go into them in a separate post on line limits.
For a new build, draw the lines on the floor plan before the electrician starts. A villa usually needs more than one line, and extra lines are far easier to plan than to add.
3. Are the cable routes separate from mains?
The bus cable runs beside the power wiring, but it should not be pulled through the same conduit by habit. Ask your electrician and your KNX integrator how the bus cable and the mains cable will be separated in conduits and in each wall box. KNX is a low-voltage system, and mixing the two in one box is where mistakes happen.
- Mark the bus routes on the drawing, with a conduit for each branch.
- Use KNX-certified bus cable, not spare network cable.
- Do not loop the bus into a ring. A KNX line can be a line, star or tree, and a ring is not possible.
- Keep the sheath of any second auxiliary supply cable a different colour from the bus cable.
4. Are the wall boxes deep enough, and is the supply planned?
Touch panels need more than a bus connection. As an example, the MDT Glass Touch 4-inch panels have a 92 by 92 mm front plate, and the datasheet lists an installation depth of 22 mm in the switch box. The panels also need a separate 24 V DC supply on top of the bus, within the working range the MDT datasheet gives, which we covered in our post on the 4-inch panels.
Two practical consequences follow. First, a 24 V supply has to be placed in the board and a pair of conductors run to each panel. Second, the datasheet lists switch box formats that do not include Indian modular boxes, so ask for the installation drawing and confirm that your box fits, with depth to spare, before civil work starts. We would rather ask that now than promise a fit nobody has checked.
5. Who owns the ETS file?
ETS is the engineering tool used to program KNX devices. The project file holds the system's addresses and logic. Without it a later integrator has to rediscover the installation. Write this into the contract: the ETS project file, a device list and the passwords are handed over at completion, in your name.
6. What should keep working without internet?
KNX devices talk to each other over the bus, so lighting, blinds and climate keep working with the internet off. Remote access and voice assistants are different: they need a server and an internet connection for the cloud part. Decide which functions must always work locally, such as lights and blinds, and which can depend on the internet, such as voice and remote access.
A one-page version
| Item | Settled? |
|---|---|
| Board space and channels counted, with spares | Yes or no |
| Bus lines drawn on the plan, supplies placed | Yes or no |
| Bus and mains routes separated and marked | Yes or no |
| Wall-box depth and 24 V supply confirmed for touch panels | Yes or no |
| ETS file, device list and passwords named in the contract | Yes or no |
| Local-only functions listed | Yes or no |
Questions people ask
Can the KNX bus cable share a conduit with mains?
Ask your KNX-certified integrator how the two will be separated on your project, and follow the electrical code that applies. We do not give a general rule here.
Do I need a different cable for touch panels?
The panels connect to the bus like other KNX devices, but several also need a separate 24 V DC supply. Check the datasheet of the exact model.
When should the integrator get involved?
Before the electrical drawings are final. Routes, panel space and keypad positions are cheap to settle on paper and costly after the plaster.
Have a plan or electrical drawing you want checked? Send it to us: talk to our team.
Sources checked on 7 November 2026
- Morion Automation, KNX cable in India, for line limits, 30 V DC SELV, avoiding rings and cable colour.
- Morion Automation, KNX in India, for early integrator involvement and the ETS project file.
- MDT Technologies, Glass Touch Smart datasheet, for the 92 mm front plate, 22 mm installation depth and 24 V auxiliary supply.
KNX wiring India projects are decided before the plaster, not after it. Six things need an answer while the walls are still open: the distribution board and its channels, the bus lines and power supplies, the cable routes, the wall-box depth and supply for touch switches, who owns the ETS file, and what must keep working without internet. This checklist takes them in that order.
1. Is the distribution board sized for the channels?
In a KNX system the switching and dimming happen in actuators, usually in the distribution board. An actuator is sized by its channels, so every circuit you want to control needs a channel, and the board needs room for the actuators, the power supplies and a margin.
- Count the lights, blind motors, fan and air-conditioning circuits per room before the board is drawn.
- Leave spare channels and spare space on the rail. Rooms get added during a build.
- Allow room to work: terminal access, labels and ventilation.
2. Where do the bus lines and power supplies go?
A KNX line carries both data and power on one twisted pair, at 30 V DC SELV, fed from a KNX power supply in the board. A line has limits: up to 64 devices with a 640 mA supply, 350 m of cable from the supply to the furthest device, 700 m between any two devices and 1,000 m in total. Those figures are in our KNX cable guide. We go into them in a separate post on line limits.
For a new build, draw the lines on the floor plan before the electrician starts. A villa usually needs more than one line, and extra lines are far easier to plan than to add.
3. Are the cable routes separate from mains?
The bus cable runs beside the power wiring, but it should not be pulled through the same conduit by habit. Ask your electrician and your KNX integrator how the bus cable and the mains cable will be separated in conduits and in each wall box. KNX is a low-voltage system, and mixing the two in one box is where mistakes happen.
- Mark the bus routes on the drawing, with a conduit for each branch.
- Use KNX-certified bus cable, not spare network cable.
- Do not loop the bus into a ring. A KNX line can be a line, star or tree, and a ring is not possible.
- Keep the sheath of any second auxiliary supply cable a different colour from the bus cable.
4. Are the wall boxes deep enough, and is the supply planned?
Touch panels need more than a bus connection. As an example, the MDT Glass Touch 4-inch panels have a 92 by 92 mm front plate, and the datasheet lists an installation depth of 22 mm in the switch box. The panels also need a separate 24 V DC supply on top of the bus, within the working range the MDT datasheet gives, which we covered in our post on the 4-inch panels.
Two practical consequences follow. First, a 24 V supply has to be placed in the board and a pair of conductors run to each panel. Second, the datasheet lists switch box formats that do not include Indian modular boxes, so ask for the installation drawing and confirm that your box fits, with depth to spare, before civil work starts. We would rather ask that now than promise a fit nobody has checked.
5. Who owns the ETS file?
ETS is the engineering tool used to program KNX devices. The project file holds the system's addresses and logic. Without it a later integrator has to rediscover the installation. Write this into the contract: the ETS project file, a device list and the passwords are handed over at completion, in your name.
6. What should keep working without internet?
KNX devices talk to each other over the bus, so lighting, blinds and climate keep working with the internet off. Remote access and voice assistants are different: they need a server and an internet connection for the cloud part. Decide which functions must always work locally, such as lights and blinds, and which can depend on the internet, such as voice and remote access.
A one-page version
| Item | Settled? |
|---|---|
| Board space and channels counted, with spares | Yes or no |
| Bus lines drawn on the plan, supplies placed | Yes or no |
| Bus and mains routes separated and marked | Yes or no |
| Wall-box depth and 24 V supply confirmed for touch panels | Yes or no |
| ETS file, device list and passwords named in the contract | Yes or no |
| Local-only functions listed | Yes or no |
Questions people ask
Can the KNX bus cable share a conduit with mains?
Ask your KNX-certified integrator how the two will be separated on your project, and follow the electrical code that applies. We do not give a general rule here.
Do I need a different cable for touch panels?
The panels connect to the bus like other KNX devices, but several also need a separate 24 V DC supply. Check the datasheet of the exact model.
When should the integrator get involved?
Before the electrical drawings are final. Routes, panel space and keypad positions are cheap to settle on paper and costly after the plaster.
Have a plan or electrical drawing you want checked? Send it to us: talk to our team.
Sources checked on 7 November 2026
- Morion Automation, KNX cable in India, for line limits, 30 V DC SELV, avoiding rings and cable colour.
- Morion Automation, KNX in India, for early integrator involvement and the ETS project file.
- MDT Technologies, Glass Touch Smart datasheet, for the 92 mm front plate, 22 mm installation depth and 24 V auxiliary supply.
