User's Manual

ADCP-75-132 • Issue 2C • August 2006

Page 20

The DC power cable and optical fibers should be routed to the DRU front panel for connection.

The antenna coaxial cable should be routed to the DRU rear panel for connection. A minimum of

3 inches (76 mm) of clearance space should be provided on all sides of the DRU (except the

bottom) to ensure there is adequate air circulation for cooling. In addition, at least one surface of

the DRU installation area must be open to the interior of the building. If a portable/flexible

antenna will be installed, a minimum of 9 inches (229 mm) clearance should be allowed on the

surface that is perpendicular to the antenna. Refer to Figure 4 for the DRU dimensions.

3.3 Powering Requirements

3.3.1 DHU and DEU Powering

The DHU and DEU are powered by 120–240 VAC (50/60 Hz) which is supplied through a

standard three-conductor 120 VAC power cord. The power cord is provided with the unit and

is 98 inches (2.5 m) long. Both the DHU and the DEU have a current rating of 2.0 Amps at

120 VAC input. Each unit should be located so that an AC outlet is within the reach of the

power cord.

If back-up powering is required, it is recommended that the building Uninterruptible Power Supply

(UPS) system be used to provide back-up power to the DHU and DEU in the event of an AC power

outage. This will also power all the DRU’s that are powered by the DHU or DEU.

3.3.2 DRU Powering

The DRU is powered by 48 VDC power which is input to the DRU through the front panel RJ-

45 connector. Power to the DRU may be provided by the DHU, DEU, or by a 120 VAC to 48

VDC power converter (available separately as an accessory item) plugged into a properly

grounded 120 VAC outlet. The DRU has a current rating of 400 mA at 48 VDC input.

If the DRU will be powered by the DHU or DEU, the power cable must be fabricated on-site by the

installer. Category 3 or 5 twisted pair cable should be used for the power supply cable. The maximum

recommended length of the power cable is 500 meters. The power cable must be routed between the

DHU or DEU and the DRU. Both ends of the power cable must be terminated with a male RJ-45

connector. If the DRU will be located more than 500 meters from the DHU or DRU, it must be locally

The DRU may be powered locally by the AC/DC converter, shown in Figure 10, which is

available as an accessory item. The converter is a UL Listed stand alone Limited Power

Supply (LPS) unit with a rated output of 48 VDC at 1.2 Amps. The converter is equipped

with a 6-foot (1.8 m) DC power cable which is terminated with an RJ-45 male connector. The

converter is powered by 120–240 VAC (50/60 Hz) power which is supplied though a standard

three-conductor 120 VAC power cord. The power cord is 6 feet (1.8 m) long and is provided

with the converter.