ABB Busch E-contact System Manual page 90

Information about planning and application
Constant light switch in comparison to constant light control
Depending on the version, the presence detectors offer various options to ensure that the
brightness in the room is maintained at a more pleasant level. There is a difference between the
functions of the constant light switch and the constant light control. Both functions ensure that
the brightness does not drop below a certain level when persons are in the room.
The use of a presence detector is especially practical for work stations in an office, since even
small movements are detected.
The constant light switch, relay or e-contact is required on the output side, can switch lamps on
and off. The constant light control, as DALI model or in combination with an LED dimmer insert
flex, can additionally control the brightness of lamps in order to maintain a constant level. Both
functions operate in dependence of light conditions and movement in the detection area.
The devices can operate either in "Automatic" or "Semi-automatic" mode.
If semi-automatic is selected, for example, the light must be switched on manually via a control
element. The light remains on as long as movement is detected and daylight is not sufficient. If
no movement is detected, the switch-off delay expires. Only then are the connected lamps
switched off.
In automatic mode the movement sensor also takes over the switch-on function as soon as
someone enters the room.
Constant light switch
The presence detector switches on lamps in the room as soon as movement of a person is
detected and the desired brightness value(setpoint) is not attained by the entering daylight
alone. The light remains on as long as people are in the detection range. The presence detector
automatically detects when the daylight is sufficient. The lamps are then switched off again to
save energy.
Fig. 43: Control for constant light switch function
[A] Artificial light curve
[B] Sunlight curve
[1] Setpoint (lx), settable on presence detector (500 lux)
[2] Minimum time above the switch-off threshold (is specified by internal device parameters)
System Manual 2CKA001473B9577 │90