Qbus is a 2-wire bus system with a central controller.

The controller has 1, 2 or 3 bus connections. From this bus-connection, a two-wire bus connects all other Qbus modules in the electrical distribution board and in the building, supplying both power and control to all of these modules.

The bus can be put in any topology (closed loop, star, tree or a combination of these). On top of this, all Qbus modules recognize the bus polarity which allows them to be connected on that bus without taking the polarity into account.

Each bus can supply between 200mA (CTD01(E)) and 500mA (CTD02(E) and CTD03E). Knowing that the average power consumption of a Qbus module is 10mA, this means between 20 and 50 modules can be connected on each bus from a power supply perspective.

Any cable can be used as buscable, as long as it contains 2 conductors of each 1mm2 minimum section (could also be multiple conductors put together as long as in the end each string of conductors have minimum 1mm2 section).

The length of the bus is restricted to 200 meters between the controller and the module at the greatest distance from the controller. We strongly recommend to lay the bus in a closed loop; in this case we have a 400 meters loop.