User manual

7.0 Installation; Electrical
7.1 Local Electrical Voltage
Before switching on the D&R power supply, check the AC
voltage of the supply by looking at the sticker on the back
of the 19" housing. This should be 110 volts for areas with
AC voltages from 100 to 120 Volts and 220 Volts for areas
with 220 to 240 volts. The main fuse should be 6.3 amp,
20mm (fast blow) for 110 Volt service and 3.15 Amp, 20mm
(fast blow) for areas only providing 220 Volts. The Phantom
power supply fuse should be a 1 amp (fast blow). The +/- 18
Volt power fuses should be 6.3 amp, 20mm (fast blow). If you
loose one or more of the power supply LED indicators
(located on the master section), turn the power supply off
and check the fuses on the front panel of the rackmount
power supply. DO NOT RELY ON THE VOLTAGE INDICATORS ON THE
FRONT PANEL OF THE POWER SUPPLY for checking fuses. If after
you replace any fuse with the proper size, turn the power
supply on and check the three LED indicators on the master
section again. If you are still missing one or more of the
power rails, turn the power supply off and call the D&R
Technical Support Department. Do not replace the fuse with
any other type, as this could become a safety hazard, and
will void the warranty.
7.2 Electrical Wiring Procedures
To take full advantage of the excellent signal to noise
ratio of the DAYNER it is necessary to carefully read this
part of the manual. Hum, radio frequency interference,
buzzes, and instability are often caused by improper wiring
and inferior grounding systems. Sometimes the incoming
electrical ground is not adequate and a separate technical
ground must be installed for the audio equipment. Your
electric power company will provide you with all the local
electrical codes and safety regulations. There are some
ground rules to follow. All signals in a studio are
referenced to ground. This ground must be clean and free of
noise. A central point should be decided for the main ground
point and all grounds should start from this point. This
is commonly known as a "star grounding system". In some
instances, your electrical contractor has daisy chained the
ground and that is not suitable for your studio. The best
way is to run a separate ground wire from each outlet and a
separate shield for al your equipment. A separate wire from
all the equipment racks to the starpoint is nice to have in
cases where the ground on the a/c outlet is not
satisfactory. The starpoint should be located at the rear of
the console or equipment rack. Install separate "clean and
dirty" a/c outlets. The "clean" ones are for audio equipment
and the "dirty" ones are for lighting, air-conditioning,
freezers, etc. Do not mix up these two sorts of outlets.
A/C interference can be isolated by introducing an isolation
transformer for the clean outlets. Ground the transformer
directly to the technical ground or as close as possible to
the incoming ground. All equipment must be located as far
as possible from the main breaker panel. Unbalanced
equipment may need to be isolated from the rack to
avoid ground loops.
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