User manual

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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

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 also have Always avoid that cables are making a loop. So-called

an overall shield. 'ring intercom' should not physically be cabled as a

Use flexible cables.

Use flexible single and multipair microphone cable power supply position) as the centre of the star.

instead of cable with solid cores, especially when the

cable is subjected to bending during operation or

installation. Keep intercom cables away from high energy cables,

Separate cable screen to XLR pin 1.

The screen of each separate microphone cable and/or Intercom cables should cross high energy cables at an

the screen of each single pair in a multipair cable, angle of 90 only.

should be connected to pin 1 of each XLR-3 connector. Intercom cables should never be in the same trunking

Do not connect this cable screen to the metal housing as energy cables.

of the connector or to metal wall boxes (outlets).

See page 8 for Earthing Concept.

Cable trunks, connection boxes and overall

multipair cable screen to clean earth.

Metal cable trunks, metal connection boxes and overall user stations are placed.

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 8 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

should be mounted in such a way that they are isolated planned network with a list of all user stations and their

from other metal cable and connector housings and positions, and we are happy to advise you on cabling

from any other metal construction parts. lay out.

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

Keep cables away from electromagnetic sources.

e.g. 110/220/380V mains power or dimmer controlled

feeds for spotlights.

Place power supply in a central position.

In order to avoid unacceptable power losses, place the

power supply as close as possible to where most

power consumption occurs or, in other words, most

Connect ASL power supply to a 'clean' mains outlet

dimmer controlled lighting systems.

In case of more complex installations, don't hesitate to