User's Manual

5-1

DMS-MTX DualMode Metrocell Cell Site Description

Power and Grounding Requirements

Cell sites are built to house communication equipment of the cellular

telephone network. Cellular equipment can be located in stand-alone sites or

in larger buildings in urban areas. Cellular equipment is traditionally powered

from a +24 Vdc power plant. Some switching equipment can also be located

in a cell site. It is connected with other equipment through CO cables. RF

signals are transmitted using coaxial cables through areal antennas. Since cell

sites are susceptible to lightning strikes, extra precautions have to take place

to ensure the operation.

Safety requirements

Safety standards for installation and maintenance of electrical equipment are

the object of the national codes; Canadian Electrical Code (CEC) in Canada

and the National Electrical Code (NEC) in the USA. Although these codes do

not govern installations of communication equipment under the exclusive

control of communication utilities, it is good design and installation practice

for the new equipment or system to comply with the intent of the appropriate

Code. For systems installed at the customer premises outside of the above

communication utilities, compliance with the Code is mandatory.

One of the basic safety rules of the national codes (CEC and NEC) in North

America, for example, requires that there shall be no objectionable current on

the Framework Ground conductor (grounding conductor). In practice, this

usually means no measurable current.

In view of the above, communication equipment shall use a three wire

distribution system as required by the codes (system with separated

grounding such as Floor Ground and grounded conductor such as Battery

Return or the neutral) rather than two wire power distribution system (system

with joined grounding and grounded conductor).

Note:

Countries outside North America may have different safety

standards codes. Follow the safety standards for installation and

maintenance of electrical equipment in your country accordingly.