Constant Lighting Control - ABB i-bus KNX Product Manual

®
ABB i-bus KNX
4.7

Constant lighting control

© 2008 ABB STOTZ-KONTAKT GmbH
Planning and application
Constant lighting control is possible with the Light Controller LR/S x.16.1 in
conjunction with the Light Sensor LFU 2.1. The following illustration indicates
the principle function of constant light control.
Setpoint
+
Actual value =
sensor value
Recorded
brightness value
Principle representation of constant lighting control
With constant light control this is a so-called fixed (or constant) value control
or interference variable control. The interference variable in our case is the
incidence of daylight. The setpoint is the brightness value which should be
set automatically in the room. The setpoint is stored during the
commissioning in the Light Controller with the calibration of the artificial
lighting or daylight or is read via the object Setpoint in the Light Controller.
The technical lighting properties of the room and the characteristic of the
luminaries are automatically determined during the artificial lighting
calibration by the Light Controller LR/S x.16.1. This parameter uses the Light
Controller for determination of the controlled system. The Light Controller
sets the brightness (luminaries) so that the control divergence between the
setpoint and the actual value is equal to 0.
The Light Controller sets constant room brightness levels by the addition or
removal of artificial lighting. This constant room brightness is often selected
so that sufficient lighting is available for an optimum working environment.
The following DIN EN 12464-1 compliant brightness levels must be
observed for special working conditions:
•
Self-service restaurants
•
Open-plan offices
•
Assembly of precision devices, e.g. radio and television sets
In ideal cases the daylight is sufficient to ensure optimum brightness levels
at the place of work. In this case the artificial light is completely switched off
by the Light Controller. If the level of daylight is not sufficient for the setpoint,
artificial lighting is added until the setpoint brightness is achieved.
Controller
LR/S x.16.1
Light sensor
LF/U 2.1
+
Absorption and
reflection attributes of
the room
Brightness value
Daylight share
1-10 V control value
Brightness value
Artificial light share
+
200 lx
500 lx
750 lx
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