Cisco MGX MGX 8800 Hardware Installation Manual page 356

Site Requirements for the MGX 8880 Media Gateway
DC Power
DC power is supplied to the MGX 8880 Media Gateway through one or two DC PEMs. Each DC PEM
must be connected to a dedicated 60-A regulated source. Each branch circuit must have a 60-A circuit
breaker at the source.
Wires connecting the PEMs to the sources should be capable of carrying 60 A. A 6-AWG (10-square
mm) copper wire is recommended. Consult the local or national codes for conductor sizing for DC
supply connections if necessary.
For more information about the DC PEM, see the
Note
DC power sources must be dedicated DC branch circuits. Each branch circuit must be protected by a
dedicated circuit breaker. The circuit breaker must have a rated trip delay time greater than that of the
MGX 8880 Media Gateway circuit breaker.
The MGX 8880 Media Gateway uses a 60-A, 1-pole circuit breaker with a short trip delay on each –48
V input. It is recommended that the site have a dedicated 60-A, 1-pole circuit breaker with a medium
trip delay at each branch circuit.
Connect the safety grounding wire to a solid earth ground. It is recommended that you use a ring terminal
lug to terminate the ground conductor at the ground stud. For details, see the
the Cisco MGX System" section on page
The –48 VDC return, logical grounds, and safety grounds are connected to the equipment chassis;
Caution
therefore, you must use a low-impedance connector to connect the chassis ground to the earthing ground.
Connect the MGX 8880 Media Gateway only to a –48 VDC source that complies with the SELV
Note
requirements in UL 1950, IEC 950, EN 60950, and CSA C22.2 No. 950-95.
Power Consumption Calculation Tables
You can use
Table 3-28
Front Card
AXSM-1-2488/B
•
•
•
AXSM-2-622-E
•
Cisco MGX 8800/8900 Series Hardware Installation Guide
3-64
Table 3-28 to calculate the typical power requirement for a MGX 8880 Media Gateway.
Power Consumption Calculation for MGX 8880 Media Gateway
Components
SMFLR-1-2488/B
SMFSR-1-2488/B
SMFXLR-1-2488/B
SMFIR-1-622/C
"DC Power Entry Module" section on page
C-8.
A B
Number of Cards Watts per Card
Installed
85.8
19.4
19.4
19.4
80
12
Releases 2 - 5.2, Part Number OL-4545-01, Rev. H0, May 2006
Chapter 3 Preparing for Installation
1-30.
"Bonding and Grounding
C D
Total Card Total 48-V Current
Power (ADC)
(AxB) (C/48)