How does Open Loop work and when to use as Daylight harvesting mode?

Open Loop mode can be chosen to control larger areas with multiple adjacent control zones in dimming applications (e.g., an open office).

This mode is also recommended for high-bay applications with skylights. Here, the sensor can be mounted in the lightwell of a skylight.

Open Loop systems measure only the incoming daylight, not the contribution from the electric lighting.

The daylight sensor should not see any electric light, and therefore it shall be mounted outside the building or inside near a daylight aperture. Open loop mode shall be chosen when a group of light devices is controlled with a single daylight sensor.

The default min and max values for operation of a daylight sensor configured as open loop will be 19 lux and 512 lux respectively. The intensity maintained by the associated light devices when daylight sensor detects 19 lux will be 100% and when daylight sensor detects 512 lux will be 0%. That is, when the area has sufficient lighting from daylight, the electric lights are turned OFF and when the area has no sufficient light, the electric lights will be turned ON with 100% intensity.

When 512 lux is configured as the Max value, all light levels detected by the daylight sensor greater than or equal to 512 lux is considered to be the sufficient light. When 19 lux is configured as the Min value, all light levels detected by the daylight sensor less than or equal to 19 lux is considered to be no light.

When the sensor detects a light level within this range the lighting will be linearly varied such that as incoming daylight is less intensity of the electric lights increase and as incoming daylight is more intensity of electric lights decreases. The daylight sensor detects the light falling on it at an interval called Sensitivity and the changes in the lighting by devices will be attained within the Fade time

When to use Open Loop as the Daylight harvesting mode?

Open Loop mode can be chosen to control larger areas with multiple adjacent control zones in dimming applications (e.g., an open office).

This mode is also recommended for high-bay applications with skylights. Here, the sensor can be mounted in the lightwell of a skylight.

Open Loop systems measure only the incoming daylight, not the contribution from the electric lighting.

The daylight sensor should not see any electric light, and therefore it shall be mounted outside the building or inside near a daylight aperture. Open loop mode shall be chosen when a group of light devices is controlled with a single daylight sensor.

You can also visit the following sections for more information:
To know how to configure Open Loop as the Daylight harvesting mode, click here
To know about Daylight harvesting using Closed Loop mode, click here
To know about Daylight harvesting using Custom mode, click here
To know about Automated Demand Response, click here
To know about Human Centric Lighting, click here