User's Manual

044-05117
breaker be installed in the power distribution unit for each amplifier. DC wire smaller than 8 mm
2
90°C copper should not be installed. Each amplifier should have its own DC cable pair. Refer to
Table 2-1.
According to the laws of probability used to formulate Erlang tables, rarely are all channels
transmitting at the same time. We can use Erlang tables to predict typical maximum current
usage. Table 2-2 and Table 2-3 describe the current load (at 120 Watts typical) for a 3 sector
(70%), 2 sector (80%) and omni (90%) site in two different configurations. Based on table 2-2, a
600-ampere power plant may suffice in a macro-cell site, whereas, a 200-ampere or smaller
power plant may be adequate in a micro-cell site, based on the equipment configuration.
Battery backup or UPS systems should be installed in remote sites or in sites that experience
brownout conditions or generator switchovers. Adding this equipment should eliminate the need
for site visits by technicians after brownouts or power outages. Battery backup systems also
provide excellent DC filtering as a side benefit.
Table 2-2. 4-Way Combining Averaged DC Current Load
Amplifier
Power
No. Of
Amplifiers
3-Sector (70%)
Averaged Current
2-Sector (80%)
Averaged Current
1-Sector (90%)
Averaged Current
100%
Typical
120 12 *348 A 409 A
120 8 *232 A *254 A 273 A
120 4 *116 A *127 A *130 A 136 A
120 1 *29 A *32 A *33 A 34 A
* typical, based on given % of output power)
Table 2-3. 4-In/4-Out Non-combining Averaged DC Current Load
Amplifier
Power
No. Of
Amplifiers
3-Sector (70%)
Averaged Current
2-Sector (80%)
Averaged Current
1-Sector (90%)
Averaged Current
100%
Typical
120 4 *99 A *114 A
120 3 *87 A *95 A *102 A
120 2 *58 A *63 A *65 A *68 A
120 1 *29 A *32 A *33 A *34 A
* typical, based on given % of output power)
2-4 Air Conditioning
Each G3L-850-135 amplifier generates 3,074 BTUs of heat at full 135-Watt power. A 1-ton air
conditioner offsets 12,000 BTU’s of heat. The G3L-850-135 amplifier is designed to operate
within the extended low temperature and high temperature environments defined in table 1-2.
In keeping with Paragraph 2-3, Table 2-4 and Table 2-5 describe the heat load (at 120 Watts
typical) for a 3-sector (70%), 2-sector (80%), omni (90%), and typical (100%) site. Perform a site
survey to determine actual air conditioning needs.
2-2 Installation and Service Manual - G3L-850-135 Multi-Carrier Power Amplifier