Specifications

ELMo 120 Multiplexer installation and testin

2-7

Revision 2.01 ELMo 120 Multiplexer Installation and Maintenance Guide 08-01023-01

Connecting power to the ELMo 120 Multiplexer modem shelf

With the power supply turned off, connect the leads of the ELMo 120 power

harness to the -48 V dc power source accordin

to the followin

table:

Figure 2-4

Typical ELMo 120 power harness connection to -48 V dc power source

—continued—

ELMo 120 Multiplexer

power leads

Power source Terminal

connection

Red -48 V dc supply Ne

ative (-)

Black -48 V dc return Positive (+)

CAUTION

Serious equipment damage

Reversed polarities on the power feed can irreparably

dama

e the ELMo 120 Multiplexer shelf components. Be

certain power feeds are connected properly to the power

source, with the

red

lead connected to the

-48 V dc

supply (negative terminal)

as shown in the table above.

Note that this is the opposite of other (non-

telecommunications) applications, in which the red lead

is usually connected to the positive (+) terminal.

Black lead

48 V dc return

Positive (+)

Terminal

Red lead

-48 V dc supply

Negative (-)

Terminal