Programming the Photocell Set-points (Continued)
Tip: Turn the lights off with the QuickSet Pro (UTILITIES / LIGHTSPOT/MLS/LCM /
IR REMOTE / HC5) to measure the perceived light level with no contribution from the
controlled lighting.
Alternatively the SET-POINTS can be configured semi-automatically;
i) The Primary Interest is the Regulating Control Output.
With the photocell configured as DISABLED:-
Using the QuickSet Pro (UTILITIES / LIGHTSPOT/MLS/LCM / SET LIGHT LEVEL)
or HC5A (+,- Scene 1) set the required light output from the controlled luminaires and
then press and hold OK (QuickSet Pro) or Scene 1 (HC5A) until the controlled lights
"blink" to indicate that a new SET-POINT LOW has been stored and a calculated SET-
POINT HIGH has also been inserted. Using the QuickSet Pro the photocell can now be
re-configured as ACTIVE or PASSIVE if required.
With the photocell configured as ACTIVE or PASSIVE:-
1) If the lights are not already on, switch them on manually by pressing ‘UTILITIES /
LIGHTSPOT/MLS/LCM / IR REMOTE / Lu / OK’ (QuickSet Pro) or "+"
(HC5A). Fluorescent lights do not reach full output until up to 15 minutes after being
switched on, so ensure that the lights are fully warmed up before continuing.
2) Wait until the time of day when the natural light level is at the point below which you
would
want the lights to be on, and above which you
would not
want the lights to be on.
3) Start the internal self-programming mechanism by pressing ‘UTILITIES /
LIGHTSPOT/MLS/LCM / SET LIGHT LEVEL / OK’ (QuickSet Pro) or Scene 1 (HC5A).
The detector takes a photocell reading, adds a small amount and stores the value in
SET-POINT HIGH. Then it turns the lights off, makes another measurement and stores
the value in SET-POINT LOW. The lights now switch on again to acknowledge a
successful programming operation.
The two switching thresholds have now been set, and the difference between them is
equal to slightly more than the contribution made by the electric lighting. This is the
perfect amount of hysteresis to ensure that the lights will not oscillate.
6
