Telex Q II - FOH specifications Wiring Considerations Grounding

WIRING

CONSIDERATIONS

GROUNDING

To take full advantage of the excellent audio performance of DDA mixing consoles, it is essential that the installation is carried out with care and attention. All audio signals are referenced to the system earth, which must be clean and noise-free, and essentially equipotential. In addition, the earth system integrity is absolutely necessary for safety.

Do not disconnect the mains earth wire from each piece of equip- ment as this could create a hazardous situation.

If in doubt consult a competent engineer and your local electricity supply company to ensure that safety regulations are not infringed or negated.

The console metalwork MUST ALWAYS be connected to the Mains earth via the PSU lead. However, the user has a choice as regards the Audio 0V.

The Audio 0V should be taken from the Studio earthing System which should take the form of a star wired system. Decide on a central point for the main earth system and starfeed to all mains outlets and equipment racks from this point. Common electrical wiring practice is to daisy-chain earth wires from outlet to outlet, but this is not recommended for audio installations. The location of the earth system star point should be in a convenient, easily accessible position, such as the main equipment rack. The star point must then be connected to the incoming mains earth but preferably should be connected to a totally separate technical earth (if local electrical regulations permit).

This should take the form of a large copper plate or stake buried as deeply as practical into the ground (a 1 metre [39"] cop- per stake hammered fully into the ground would be suitable). This should then be fed to the studio star system via heavy gauge, low impedance cable, with adequate precautions being taken to prevent excessive corrosion of the cable/earth stake.

Q2 OPERATIONAND MAINTENANCE MANUAL 9601 12