ASL INTERCOM PS 130, Руководство пользователя

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User Manual PS 130 / Issue 1 © 1994 ASL Intercom, Utrecht, Holland.
6
7.0 CABLING
For the PRO Series Intercom system the interconnecting
cables are of the shielded two-conductor microphone
cable type and the intercom line connectors are of the
XLR-3 type. Audio and Call signals are on XLR pin 3, DC
power is on XLR pin 2. XLR pin 1 is connected to the
shield of the cable which functions as the common return
for audio and power.
Since the audio signal is transferred in an unbalanced
¼ ¼
way, certain rules have to be obeyed when installing the
cables of an intercom network. This is to avoid earth loops
and to minimize power loss and the possible effect of
electromagnetic fields.
These rules are:
Use high quality (multipair) cable. Keep cables parallel as much as possible.
For interconnecting user stations, power supplies and When two (multi channel) units in a network are
accessories in an ASL Intercom network, use high connected by more than one cable, make sure that
quality shielded two-conductor (minimum 2x 0.30 mm2) these cables are parallel to each other over the whole
microphone cable only. distance between those units. When using multipair
In case of a multi channel intercom network, use high cable, parallelism is ensured in the best possible way.
quality microphone 'multipair' cable only, each pair
consisting of two conductors (minimum 2x 0.15 mm2)
with separate shield. Multipair cable should have an
Always avoid that cables are making a loop. So-called
overall shield as well. 'ring intercom' should not physically be cabled as a
Use flexible cables.
Use flexible single and multipair microphone cable
instead of cable with solid cores, especially when the
cable is subjected to bending during operation or
Keep intercom cables away from high energy cables,
installation. e.g. 110/220/380V mains power or dimmer controlled
Separate cable screen to XLR pin 1.
The screen of each separate microphone cable and/or
angle of 90
(
only.
the screen of each single pair in a multipair cable, Intercom cables should never be in the same trunking
should be connected to pin 1 of each XLR-3 connector. as energy cables.
Do not connect this cable screen to the metal housing
of the connector or to metal wall boxes (outlets).
See page 10 for Earthing Concept.
In order to avoid unacceptable power losses, place the
Cable trunks, connection boxes and overall
multipair cable screen to clean earth.
Metal cable trunks, metal connection boxes and overall
multipair cable screen should be interconnected and,
at one point (the 'central earthing point') in the intercom
network only, be connected to a clean earth or a safety
The ASL power supply may be connected to the mains
earth. power outlet to which other audio equipment is
See page 10 for Earthing Concept. connected. Avoid using mains outlets which also power
Keep metal connection boxes and cable trunks
isolated from other metal parts.
Metal housings for intercom cables and connectors
contact us. Please send us a block diagram of the planned
should be mounted in such a way that they are isolated network with a list of all user stations and their positions,
from other metal cable and connector housings and and we are happy to advise you on cabling lay out.
from any other metal construction parts.
¼ ¼
See Party Line, Technical Concept.
Avoid closed loops.
ring. All cable routes should have a 'star' configuration,
with the central earthing point (usually close to the
power supply position) as the centre of the star.
Keep cables away from electromagnetic sources.
feeds for spotlights.
Intercom cables should cross high energy cables at an
Place power supply in a central position.
power supply as close as possible to where most
power consumption occurs or, in other words, most
user stations are placed.
Connect ASL power supply to a 'clean' mains
outlet.
dimmer controlled lighting systems.
In case of more complex installations, don't hesitate to