8
4
CALIBRATION
The general theory behind ON and OFF setpoint calibration is to set the ON setpoint at a lower
footcandle level than the OFF setpoint. This way, the controlled lights will not switch OFF during a
period when they should be ON. The difference between the ON and OFF setpoints is called the
Deadband. In general, the deadband should be large enough (about 10% of the expected calibration
range) to provide system stability.
In a dusk-to-dawn lighting application, it is important to have a deadband sufficient to prevent
confusing the control board as the desired setpoint is reached. To insure that lights are ON when
needed, the deadband should be biased to leaving the lights ON longer rather than switching them
OFF too soon.
4.1
Dusk-To-Dawn Calibration Procedure
The Dusk-To-Dawn technique of calibration has been developed that, when followed, will work well
for most calibration needs. Additionally, if you have a different lighting application other than dusk-to-
dawn, you should be able to discern the method of this technique and apply it to your situation.
The DLC-PD sensors have a very linear response which makes it simple to predict the setpoints of
the DLC-PDC Controller. Use of non-GREENGATE/
COOPER LIGHTING SOLUTIONS
sensor
will likely make this task more difficult.
This procedure has been created in such a manner as to not require any sophisticated calibration
equipment. Shown below are the tools needed for Dusk-To-Dawn calibration of the DLC-PDC.
TOOLS NEEDED:
SMALL FLATHEAD SCREWDRIVER 1/8”
PROCEDURE: begin this procedure just before dawn
1.
Switch the Input Delay Switch OFF (UP).
2.
At the time during dawn when the daylight is at the level where you would want the lights to
switch ON at dusk, turn both the High Level Setpoint and the Low Level Setpoint trimpots all
the way counter clockwise so that both setpoint LEDs are ON. The Relay Status LED will be
ON and the lighting circuit will be OFF.
3.
Turn the Low Level Setpoint trimpot clockwise to the point that the Low Level Setpoint LED
switches OFF. The Relay Status LED and lighting circuit will remain unchanged.
4.
Wait for a period of time for the light level to increase (the Low Level Setpoint LED will switch
back ON), and adjust the High Level Setpoint trimpot clockwise to the point that all LEDs
switch OFF. The DLC-PDC should now be calibrated for a dusk-to-dawn application.
5.
Return the Input Delay Switch to the ON (DOWN) position. Note; the lights will switch Off at
dawn, but if a greater deadband is required set the High Level Setpoint trimpot ahead of the
Low Level Setpoint trimpot (adjust as required). Should the Dusk-to-Dawn lighting cycle fail
to switch the lights ON and OFF as planned, please refer to the Troubleshooting section of
this manual.