G
e
neral Information
General Information
5
Maximum line lengths
The loop resistance of each TwinBus line must not exceed max. 20 Ohm. This results in the following maximum line
lengths:
Considerations when renovating
If commercially available doorbells are used, they must not have a contact transition resistance in excess of 10 Ohm.
Connection to the mains
Please note that a 230 V/AC power supply is required for the power supply units and mains transformers which are
not explicitly depicted in the block diagrams.
Electrostatic charging
Intended use
The RITTO door intercom is a system devised for controlling access and internal communication inside residential
buildings.
Any other use is considered unintended use. The manufacturer is not deemed liable for any damage resulting from
unintended use. The risk, in this case, is assumed solely by the installation technician.
Intended use also includes observing the manufacturer's regulations concerning use and maintenance. The system
may only be installed and serviced by persons familiar with it and informed of the risks involved.
Wire diameter in mm
0,8
0,6
Resistance in Ohm/m
0,0349
0,0621
Line lengths between TwinBus power supply unit 1 7573 and indoor telephone or
indoor video station
280 m
160 m
Line lengths between TwinBus power supply unit 1 7573 and door unit (lighting)
60 m
30 m
Line lengths between TwinBus power supply unit 1 7573 and door openers up to
8 V/1 A
50 m
30 m
Line lengths between power supply unit 1 4874 and indoor video station
100 m
60 m
Line lengths between mains transformer 1 6477 and indoor video station
50 m
35 m
Line lengths between mains transformer 1 6477 and camera module
35 m
25 m
Note:
In the case of existing YR cables, all the free wires on the TwinBus power supply unit must be laid
as screening to a Terminal b.
Caution!
Equipment damage through overvoltage or short circuiting
Equipment damage can occur through overvoltage or short circuiting. Connection must be made to
a 230 V~±10% mains power outlet. The power must be fed via an intrinsic line safety switch with
max.10 A.
Caution!
Risk of equipment damage through static electricity (ESD)
Static electricity could destroy equipment if direct contact is made with the printed circuit boards.
Discharge electrostatic charges before touching the equipment.
