Specifications

Common Equipment Description 2-7
Power Entry Options
Typical MGX 8220 Hardware Weights
Power Entry Options
DC Powered Systems
In DC powered systems MGX 8220 supports one or two power entry modules (PEMs) each of which
can be connected to its own independent 48VDC supply. The power entry modules are installed
horizontally, side by side in the bottom rear of the shelf. (See Figure2-4.) Each module is powered
from a 48VDC power source via three wires:
• positive ground
• –48 V DC
• safety ground
The 48 VDC cable is connected to the power entry module through a 3- position EURO Block
connector. The two modules provide power supply redundancy. Each power entry module is capable
of supplying enough power for a fully loaded MGX 8220 shelf.
An illustration of a power entry module is shown in Figure2-5.
Figure2-5 MGX 8220 Power Entry Module
Each power entry module contains its own circuit breaker which also acts as an ON/OFF switch. The
circuit breaker is closed by pressing in the large black button until it latches in the closed position.
The circuit breaker is opened by pressing the smaller red button. The DC PEM also includes a
bracket which is attached to the PEM to provide cable strain relief. Refer to Chapter 7, “Installation
and Start-up” for details.
Hardware Weight (lbs)
MGX 8220 shelf with 16 boards 68
MGX 8220 main cooling unit 20
MGX 8220 booster cooling unit 14
MGX 8220 plenum 8
Average single MGX 8220 board 1.9