Specifications

Installation and Start-up 7-3
Site Preparation
Site Preparation
Site preparation involves space, power, and cooling considerations.
Rack and Space
The MGX 8220 shelf is designed for mounting in a standard 19 inch rack. The MGX 8220 site
requires a 19 inch rack with sufficient available mounting units for the modules to be installed (5U
for each shelf, 3U for the main cooling assembly, 2U for the booster cooling assembly, 2U for the
plenum chamber, or 1U for the spacer unit and 3U for the AC power module). The rack should have
a set of mounting rails at the front and a second set at the rear or in a designated intermediate
position. There must be sufficient clearance around the rack to allow removal and replacement of
front and back cards and for the attachment and routing of cables to the line modules. Ideally there
should be at least 3 feet clearance in the front of the rack and 2 feet clearance in the back of the rack.
Power
The MGX 8220 shelf can be configured for either AC or DC power.
An easily accessible AC or DC power source must be available within six feet of the MGX 8220
system. Before powering up the node, verify that the MGX 8220 node is powered from a dedicated
branch circuit. An easily accessible disconnect device should be included in the facility wiring.
• DC Version
For the DC version, a 48VDC power feed is required. For power supply redundancy, two such
power feeds (preferably from independent power sources) are required. Each power feed must be
capable of supplying 500 watts.
A 20A DC circuit breaker is recommenced for the 48VDC power source which supplies
DC power to each MGX 8220 shelf. In North America this circuit breaker should protect against
excess currents, short circuits, and earth faults in accordance with national and local electrical
codes. These codes are mentioned in the section, “Safety Recommendations”. The dedicated
circuit breaker should be sized such that the rated current and the trip delay is higher and longer
than the MGX 8220 circuit breaker. A 20A, 1-pole DC circuit breaker with a long trip delay is
recommended.
For information purposes, the MGX 8220 shelf uses a 15A, 1-pole DC circuit breaker with
medium trip delay on the -48V input. The circuit breaker manufacturer is ETA (part number
43-500-P10-15A).
The DC power connectors attach to the power entry modules at the rear of the shelf through
EURO Block 3-pin connectors. For power and ground connections to the MGX 8220 shelf,
a 12 AWG conductors must be used. If the 48VDC source has wires of a different gage, that
accepts the source wires as input and provides as output 12 AWG wires to the MGX 8220 DC
connector, a customer supplied terminal block must be provided. Only power supplies complying
with SELV requirements in EN 60950, UL 1950, IEC950, can be connected to the 48VDC input
of the MGX 8220 system.
• AC Version
For the AC version, a AC power source is required. For power supply redundancy, two such AC
sources, (preferably independent) are required. Each source should be capable of supplying
500 watts per shelf. The AC power cables from the AC source attach to the AC power module
which is mounted below the shelf and cooling assembly.