Installation guide

System 5 Installation Guide28
Grounding
The main service entrance should contain the only neutral-ground bond, except in the case of a separately derived system, such
as an isolation transformer. Avid recommends that the neutral-to-ground voltage in a 120 V, single-phase system be less than 3 V
RMS. In high-availability systems, a neutral-to-ground voltage above 0.5 V has been identified as a possible source of distur-
bances. Ground leakage currents should be 0.0035 A or less.
Ground resistance is due to the resistivity of the soil in the vicinity of the grounding electrode. Most computer manufacturers rec-
ommend a maximum ground resistance of 2
.
Uninterruptible Power Supply (UPS)
UPS devices provide continuous power, even when utility supply power is interrupted or lost. Since the power on an on-line UPS
flows through a rectifier and inverter before reaching the load, most power disturbances are eliminated through constant filter-
ing. Therefore, an on-line UPS is a good idea for all high-availability systems operated in environments that cannot guarantee
high-quality power. Most UPS devices have a voltage regulator to compensate for the voltage variances described above.
Typical Room and Equipment Layout
If it is determined that your facility is below standard in any of the specifications described above, we recommend contacting an
experienced electrician (or engineering consultant for large facilities) with expertise in power quality issues.
Typical Room and Equipment Layout for System 5
Changeover SwitchEU
EUCON Switch
System Computer
Changeover Switch
(optional)
DF66/DF70 SuperCore(s)
Mic-Line IF & Patch
Mic-Line ADC
Analog IF & Patch
AES/EBU IF & Patch
Monitor IF & Patch
Monitor DAC
HD/SD Embedder/
De-embedder (optional)