DALI line planner

How many DALI lines and power supplies a floor needs, before anyone draws a schematic.

What goes on the lines

Control gear is the thing that switches the light (LED drivers, ballasts). Control devices are the things that send commands (sensors, wall panels, input units). Bus currents are typical starting points, check the datasheet of the product you are using.

Line settings

Kept free for voltage drop, tolerance, supplies that give less than their rating, and devices added later. 20 % is a common planning figure, not a standard.

A DALI line has 16 groups. Count the groups that must work together in one space.

Result

How this is worked out

The line count is the highest of three separate limits. Whichever is highest decides it.

The three limits

  • Addresses: 64 control gear per line, so gear / 64, rounded up.
  • Control devices: 64 DALI-2 device addresses per line, so devices / 64, rounded up. A multisensor is one address but may use several instances; check its datasheet.
  • Bus current: sum of quantity x current, against one line's supply minus the spare margin, rounded up.

Groups, supplies and the split

  • A line has 16 groups and 16 scenes, so an area needing more than 16 can't sit on one line.
  • Every line needs its own power supply, unless the router or controller has one built into each subnet.
  • The count goes up one more if splitting gear and devices evenly would still push a line over budget.

What draws from the bus

  • Bus-powered sensors and panels draw from the line. Mains or low-voltage powered ones draw little or nothing: enter the datasheet figure.
  • Control gear draws very little. The standard caps it at 2 mA each.

Sources

  • IEC 62386-101: 64 addresses, 16 groups, 16 scenes, 250 mA per line. IEC 62386-102: 2 mA per gear. IEC 62386-103: 64 device addresses.
  • Helvar data on this site: 905/910/920 controllers give 250 mA per subnet (905 one subnet, 910 and 920 two) and don't support DALI-2 devices; 402 supply 250 mA, 407 up to 64 mA; sensors 6 to 60 mA, most about 10 mA; 14xD2 panels 10 mA max, 19x Illustris 22 mA typical.
  • See power supplies and repeaters and routers and controllers.

Results are a planning aid, not a design sign-off. Check the figures against the manufacturer's datasheet for the exact product, or ask us to check them with you.IP Geolocation by DB-IP