DiGiCo SD Rack - Manual (Page 4)

SD Rack
1-4
1.1 Introduction
1.1.1 SD-Rack Unit and Modules, Installation Notes .................
The SD-Rack Unit is a 19-inch chassis with a control panel and PSUs at the top. It is a standard 19" rack mount wide, 365mm deep,
excluding connectors and 10u (445mm) high.
Rack Mains Earthing
The SD-Rack Unit must be earthed to the mains earth according to the safety instructions included with the mixer system.
The rack has twin supplies each with their own separate mains power connections, with 2 IEC mains inputs per rack, which must be
separately connected to the mains earth.
Rack Power Supply, Installation
The SD-Rack Unit contains 2 model MOD-SDR-PSU . From s/n 6221/1203 these are supplied with listed component approval to UL/
EN/IEC/CSA 60950-1. Units built to this standard are marked with the ETL mark. These units are intended for operation ONLY in the
SD-Rack. No attempt should be made to operate or install these supplies other than in the SD-Rack, only in the manner described here.
The rack will operate on only 1 supply. Supply units on the SD-Rack can be switched off, removed and replaced whilst the other is use
(hot swappable)
Rack Power Supply, Cooling
The SD-Rack Unit has twin supplies each with their own separate mains power connections, with 2 IEC mains inputs per rack.
At least 1U (45mm) of space should be left above and below the rack unit to allow ventilation, and to prevent heat
transfer from adjacent equipment. At least 100mm / 4” should allowed to side of the units to allow heat dissipation.
At least 100mm / 4" free air should be left at both the front (plain) side and the rear (connector) side of the rack to allow ventilation.
However this clearance is usually required at a rack face and to allow connector access at the rear in any case.
Under no circumstances should the fan outlets be blocked or restricted.
The supply approval covers use in ambient air temperatures up to 35 deg C. Operation in temperatures above this should be avoided.
Rack Control Panel Connections
MADI I/O BNC 4 sockets (2 Pairs) of I/O to Console
MADI output / split BNC 2 sockets to Console or recorder etc.
Optocore HMA 2 Bidirectional dual connector (optional), Neutrik 2 x OpticalCON Duo (optional), ST Optical x 4 (optional)
Word Clock Out BNC socket 48/96 KHz 5V p-p
Word Clock In BNC socket 48/96 KHz 5V p-p max
USB type B
Mains Power IEC power x 2 Dual redundant supplies
Stage rack 200VA run
FOH rack 200VA run
100V-240V 50-60Hz auto sense
Requires 2 separate mains connections.
Input / Output Slots
Below the panel, the Rack Unit has Input and Output slots. Each of these slots can be filled with a different Rack Module, providing an I/
O system which is configured according to model or user requirements. SD modules in the SD-Rack can be, removed and replaced
whilst others are in use (hot swappable)
Rack Module Inputs and Outputs
There are different Rack Modules for interfacing to different digital and analogue devices. Each Rack Module carries eight channels
of audio.
The modules fall into two broad groups - those which carry only inputs or outputs, and those which carry both input and output
signals. Output modules must be installed in Output slots, while Input and I/O modules must be installed in Input slots. The rack can be
fitted with up to 7 input or I/O modules and 7 output modules (less where I/O modules fitted)
Rack Module Connections
Audio connections to the Rack Modules are made using appropriate connectors for the type of module. See the specifications for a list
of the different connectors used in the Rack Modules.
Rack Signal Earthing
The analogue earthing requirements of the Rack unit is similar to those of a conventional large analogue console. All analogue
inputs and outputs are balanced and symmetrical, but not floating, because of their transformerless design. Installers should use
good earthing practice, as with any large audio installation. Digico can provide copies of AES papers on this subject upon request.