6.3 Wiring system of entry phone in video version
6 INSTALLATION AND ACTIVATION
It is recommended to complete wiring with the application of distributors
CVR-2. Signals from the exchange are supplied to the distributors, which are
then sent to the monitors. It is possible to connect up to four monitors to one
distributor.
It is not admissible to make branchings by connection of two sections of cable
(in order to distribute signal by branchings, signal distributor CVR-x should be
used - see the next point). In parallel connection of receivers, cable should be
conducted from one receiver (monitor, distributor, commutator) to the other.
The principle should be also observed that signal comes to the receiver on one
cable and goes out by the other. Both cables are connected on clamps of the
receiver.
In entry phones with many occupants a wiring system should be made in form
of a branch. In one branch up to 10 receivers (monitors or distributors) can be
connected. The next branch can be made by treating one of the outputs from
any distributor as a beginning of a branch.
An attention should be paid to the adjustment of wire wave impedance to the
impedance of the connected equipment. In equipment installed at the beginning
and at the end of the line a resistor should be installed in parallel to the line
of value equal to cable wave impedance. In other equipment connected to the
line no load resistors should be installed. Load resistance in external panel,
monitors, distributors and switches is set by jumpers.
Mixed systems, in which uniphones and monitors are used at the same time,
are allowed.
CVR-2
8
8
CVR-1
8
8
CVR-1
8
EC-3100
2
230V
2
230V
2
230V
2
230V
Figure 7: Method of connecting monitors to electronic cassette
EC-3100
230 VAC
4
branch 1
branch 2
branch 3
branch 4
CVR-x
Figure 8: Method of signal distribution within video installation
18