ABB SA/S 12.16.6.1 Product Manual - Knx Commissioning
ABB i-bus
®
KNX Commissioning
112 2CDC 505 056 D0207 | SA/S
3.2.5
Operating mode
Heating Actuator
In the operating mode Heating Actuator, the Switch Actuators generally are
used as setting elements for electro-thermal valve drives. Room temperature
can be controlled in conjunction with a room thermostat or room
thermometer, which controls the Switch Actuator.
Various types of control are possible, e.g. PWM, 2-point control (1 bit) or
continuous control (1 byte).
Every individual output of a Switch Actuator can be controlled via a 1 bit
control value. For this purpose, the communication objects Switch of the
outputs have to be connected with the communication objects Control value
of the room thermostats/temperature controllers.
Note
The parameter of the room thermostats must be set to continuous 2-point
control
or switching 2-point control.
With so-called continuous control, a 1 byte value (0...255) is used as an
input signal. This input signal is used in the Switch Actuator in accordance
with the programmable cycle time in the ON and OFF command of the
switch relay. At 0 %, the valve is closed, and at 100 % it is fully opened.
Intermediate values are calculated via pulse width modulation (PWM).
For further information see:
Pulse width modulation – Calculation
Note
Electromechanical Switch Actuators, including SA/S Switch Actuators,
have mechanical contacts. On the one hand safe electrical isolation and a
very high switching capacity is achieved, on the other hand this is
associated with switching noises and mechanical wear.
Important
When the heating actuator mode is selected, the service life of the
switching contacts must be considered, see
This is essential if the output is used for a continuous controller.
Considering these aspects, it may be useful to use an Electronic Switch
Actuator, Fan Coil-Actuator or controller from the ABB i-bus
®
KNX range.
These actuators do not feature galvanic isolation and have a considerably
smaller switching capacity, which is sufficient. Mechanical wear and
switching noises are not an issue.