Minimum requirements on the lighting control system

The energy saving potential is marked green with the range [A]. Time difference between the time switching points depends on the latitude and the lux values defined and may be up to 20 minutes. Another area for energy saving is between 10 pm and 6 am . Here, the system may also work in dimmed operation depending on the traffic volume. As the controllability of the commonly used luminaires (high and low pressure discharge lamps) is very limited, most operators decide in favour of one of the two widespread models. Popular are 2-lamp operation and the switching off of the lamp (up to 50% energy saving) or reduced-power operation with magnetic ballasts (up to 35% energy saving). Where linear fluorescent luminaires are already used, the electronic ballast is used already more frequently.This luminaires might already have been controlled which, however, was not made because of the efficiency due to the shift of the optimal thermal operating point of the light source especially in the colder season. All in all, possible savings are rather limited compared to current developments.