Installation manual

MAXIMUM NUMBER OF DEVICES
A system can manage up to 99 zone addresses. Up to nine addresses
dedicated to the actuators can be managed for each zone. The maximum
number of devices which can be connected to the BUS also depends on their
total absorption and the distance between the connection point and the
power supply. The power supply can supply up to 1.2 A and the maximum
number of devices which can be connected to the BUS is determined by
summing the absorption of all the items and making sure that the total does
not exceed the capacity of the power supply. For the calculations mentioned
above, refer to the “Maximum absorption” parameter expressed for each
device in the “Technical features” section of this guide.
When calculating the absorptions the availability of current as a function
of the length of the BUS cable must also be considered. During the sizing
therefore respect the following rules:
• the connection between the power supply and the furthest device must
not be more than 250 m long;
• the total length of the connections must not be more than 500m;
• the maximum current available at the end of a 250 m long telephone
cable is 400 mA, while for a BUS cable item L4669 it is 600 mA;
• for best division of the currents on the BUS line the power supply should
be installed in the middle.
C
A
A = 250m
B = 100m A + B + C = 500m MAX
C = 150m
Power supply
MAXIMUM DISTANCES OF THE BUS CABLE
BUS
B
BUS
BUS
59
TECHNICAL FEATURES
CATALOGUE MY HOME TEMPERATURE CONTROL