Dc Power Entry Module; Mgx 8950 Dc Pem; Figure; Primary And Secondary Dc Pems - Cisco MGX MGX 8800 Hardware Installation Manual

Cisco MGX 8950 Switch

DC Power Entry Module

The MGX 8950 can accept power from a –48 VDC (–42 + –56 VDC) DC source that connects to one
(primary) or two (secondary/redundant) –48 VDC PEMs. Each primary or redundant DC source
connects to one DC PEM in the system. Each DC PEM accepts two 100 A service feeds from the same
DC source.

Figure 1-28

Plastic
cover
For a DC-powered system, the DC PEMs are installed at the back of the air intake plenum. If you install
only one DC PEM, install it on the bottom, as viewed from the rear of the air intake plenum.
(See
Figure 1-29
-48 V DC
-48 V DC
For more information about DC power requirements, see the
page
Cisco MGX 8800/8900 Series Hardware Installation Guide
1-44
Figure 1-28 shows a close-up of the DC PEM.

MGX 8950 DC PEM

-4 8V D C
R T N
-4 8V
-4 8V D C
50 A
Terminal
J1 output
block 1
connector
Figure 1-29.)

Primary and Secondary DC PEMs

Secondary PEM
50A RT N
-48 V
-48 V DC
50A
J1
J2
RT N
50A
-48 V
-48 V DC
50A
J1
J2
Primary PEM
3-17.
J1
J2
Circuit breaker
J2 output
connector
RT N
-48 V
-48 V DC
50A
DC
RT N
-48 V
-48 V DC
50A
DC
Releases 2 - 5.2, Part Number OL-4545-01, Rev. H0, May 2006
Chapter 1 Product Overviews
R T N
-4 8V
-4 8V D C
50 A
D C
DC OK
Terminal
LED
block 2
"Power Requirements" section on