20h
21h
22h
23h
0h
1h
2h
3h
4h
6h
Centre théorique
01h00 (GMT+1)
décalage 1 heure
Durée de la nuit = 12h
18h
19h
18h
19h
5h
8h
7h
8h
7h
Exemple 1
20h
21h
22h
23h
0h
1h
2h
3h
4h
6h
Durée de la nuit = 9h
5h
Exemple 2
la durée minimale d'allumage est de 1h
Extinc
tion 7 heures
Extinction 7 heures
Durata della notte calcolata: 12 ore
Esempio 2
Durata della notte calcolata: 9 ore
Esempio 1
TIS = (9-7)/2+1 = 2
TIM = (9-7)/2-1 = 0 -> 1
La durata minima di accensione è 1 ora
Effettivo: 7 ore
Ridotto: 6 ore
Spegnimento
impostato: 7 ore
Spegnimento
impostato: 7 ore
Centro notte
calcolato
Offset impostato: 1 ora
TIS = (12-7)/2+1 = 3,5
TIM = (12-7)/2-1 = 1,5
Night-Time Saving Module
MEP2000E - 5454356
Functions
Ideal for common areas of blocks of flats, residential areas, public areas where lights are switched on
automatically in the evening and switched off in the morning (typically by using a twilight sensor or an
astronomical clock).
A considerable amount of energy may be saved using this device, considering that lighting is not normally
needed in the middle hours of the night: lighting is usually essential only in the evening and in the morning.
The MEP2000 module allows the automatic switch-off of one or more lights in the middle hours of the night.
The time can be configured from 4 to 9 hours. The switch-off time is symmetric with respect to the middle of
the night. The central symmetry line may be shifted forwards from 0 to 2 hours (default: 1 hour) to prioritize
evening lighting time with respect to the morning lighting time.
Night time
The module must be powered only during the night, e.g. on a dedicated line controlled by a twilight sensor.
The MEP2000 module can thus calculate the time during which it remains powered considered as. The
device stores the duration of the last 4 nights and calculates the average: this value is considered as the
night time. The time will obviously vary according to the seasons
(1)
. The module will not store anything if it
remains powered for less than 5 consecutive hours.
Lighting times: evening and morning
The lighting time in the evening and morning ensured by the module can be determined by the calculations
below:
Given:
DN = night time: calculated automatically by the module as described above.
DS = Off time set by the installer (from 4 to 9 hours; default: 5 hours)
Offset = Forwards shift of the calculated symmetry line of the night, settable by the installer (from 0 to 2
hours; default: 1 hour).
Result:
Evening lighting time (TIS) = (DN-DS)/2 + Offset
Morning lighting time (TIM) = (DN-DS)/2 - Offset
In any case, the module guarantees that TIS and TIM are equal to at least one hour, by shortening the set
switch-off time as necessary. This particular case is illustrated in the second example below.
Examples of operation
(1)
The duration of the last 4 nights is preset to 15 hours by default. Therefore, the module will start working
with the correct night time after 4 days.
P5
GB
Calculated
middle of the
night
Offset set: 1 hour
Example 1
Calculated night time: 12 hours
Example 2
Calculated night time: 9 hours
Minimum lighting time is 1 hour
Set switch-off:
7 hours
Reduced to:
6 hours
Set switch-off:
7 hours
Actual:
7 hours
DS1054-008D
