111
(MT11 - Gb2006)
I
NTERCOMS *
V
IDEOINTERCOMS
*
T
ELECOMMUNICA
TION
INSTALLATION INSTRUCTIONS
General characteristics
- The cable runs of intercom and video intercom installations must be kept separate from the
mains or any other electrical installation as required by the International Safety Standards
and the entire installation must be realized in compliance with the safety rules in force in any
specific Country.
- It is necessary to provide an all contact switch before the power supply. Use a single general
switch in case of several power supplies (also in multiple entrance).
- Before connecting the power supply make sure that its rating data corresponds to this of the
mains.
- For electromagnetic reasons, all service modules must be installed near their power supply.
Wires
1) For the correct operation of the video intercom system you must choose the correct type of
cable.
2) Wires must be dimensioned according to the distance of the different devices and their current
consumption.
3) Do not connect wires in parallel to reach the required cross-section (for example multi-pair
telephone cables). Only use a single wire with suitable cross-section. When using multi-core
cables you must select them with low parasite parameters (low capacitance per metre, low
inductance over Ohm).
4) If the installation includes additional power supplies you must place them near the device to
be powered.
Background noise
To avoid possible background noise over the speech line, it is advisable:
5) not to lay intercom or telephone cables in the same runaway as the wires used to power
alternate current loads;
6) to avoid using the same multi-core cable to transmit audio signals and alternate current power
supplies (lamps, amplified external door stations, electrical door locks). Always use separate
wires for alternate current power supplies;
7) do not connect the name plate lamps (or other AC powered devices) to terminal 4 (-) of the
speaker unit; two wires must start from terminal F of the timer, one for terminal 4 of the speaker
unit and one for the connection of the lamps (or other AC powered devices);
8) for name-plate lamps, to use an additional 12Vac transformer (PRS210 type) with suitable
power (consumption is 75mA for each lamp) with 2 power supply wires separate from audio
wires;
9) for systems with long distance between the external door station and the last video intercom,
it is advisable to position the power supply near the external door station (see diagram on page
117).
WIRE CROSS-SECTION
For the video signal use a TV 75
Ω
low loss coaxial cable or a twisted pair (see next pages).
m.
50
100
200
300
mm²
S
0,5
0,75
1
1,5
mm
Ø
0,8
1
1,2
1,4
Terminals
Distance
mm²
S
0,75
1
1,5
2,5
mm
Ø
1
1,2
1,4
1,8
1 . 2 . 1D . 2D . 3D . 4 . 5
3+ . 7 . A . C+ . 9M (call)
F . H . S .
(wires in bold face type)
AWG
20
18
16
15
AWG
18
16
15
12
feet
165
330
660
990
