Section 150-231-164
Revision 04
Page 32
C. APPLICATIONS USING HIGAIN DOUBLER
HDU-451
1. GENERAL
1.01
For Doubler applications, one or two Doublers
may be used in the HDSL loops between the
HLU-231 List 6D and the HRU-412. When using two
Doublers in a HDSL loop, the HRU-412 must be locally
powered. This section addresses HLU-231 List 6D
operation with the HDU-451 List 1, 2, & 3 doublers. The
List 1 and 2 doublers have identical power
consumptions. The List 3 is a low power doubler which
consumes 40% less power than either List 1 or 2. The
Power Consumption section addresses both the high
and low power doubler versions.
2. POWER CONSUMPTION
2.01
The maximum current drain is the current drawn
from the shelf power supply when it is at
minimum voltage (-42.5 VDC) under a worst case
application. The worst case application for the HLU-231
List 6D occurs on a loop with one HDU-451 Doubler,
four 9000 foot, # 26 AWG spans, and an HRU-412 that
is providing 60 mA of CPE current. Under these
conditions the HLU-231 List 6D current drain from the -
42.5 VDC battery is 0.80 A for the List 1 and 2, and 0.58
A for the List 3 doubler. This CO current and other
related power parameters for this doubler application are
listed in Table 11.
2.02
The maximum shelf current drain allowed is a
function of the shelf -48 VDC fuse. Table 12
lists the doubler shelf deployment guidelines, as a
function of the shelf fuse, for the more popular Type 220
configuration shelves. These guidelines limit the
maximum fuse load to 85% of shelf rated capacity. Use
Table 12 when selecting the appropriate load fuses for
the Building Distribution Fuse Bus (BDFB) when
deploying the HiGain system equipment in COs.
2.03
The maximum HLU-231 List 6D power
dissipation is the power that is converted into
heat within the unit. It contributes to the total heat
generated and is used to determine the maximum
number of shelves per bay that do not exceed the
maximum power dissipation density in Watts/sq. ft.
2.04
In CO locations, the maximum power dissipation
for open faced, natural convection cooled
mountings is 120 Watts/sq. ft. as stated in NEBS
standard TR-NWT-000063 section 4.2.3. The footprint
of a 13 slot 23” SXSS shelf is 7.024 sq. ft. Thus the
maximum allowable dissipation is 840 W. This limits the
number of HLU-231 List 6D units per bay to 80 when
powering the List 1 or List 2 doubler, and to 93 when
powering the List 3 doubler. Note that this is a worst
case situation since it assumes the entire CO is
subjected to the maximum power density. More
favorable conditions would permit increasing the number
of shelves per bay without jeopardizing the CO thermal
integrity.
TABLE 11. HLU-231 LIST 6D POWER PARAMETERS WITH HDU-451 DOUBLERS (LIST 1, 2, & 3)
60 mA CPE
Current
CO Voltage
Volts
CO Current
Amps
Power Consumption
Watts
HLU Power Dissipation
Watts
List 1 & 2
List 3
List 1 & 2
List 3
List 1 & 2
List 3
OFF
42.5
0.65
0.50
28
22
9.5
8.25
OFF
48
0.59
0.41
28
22
9.5
8.25
OFF
56
0.5
0.38
28
22
9.5
8.25
ON
42.5
0.80
0.58
34
25
10.5
9.0
ON
48
0.70
0.52
34
25
10.5
9.0
ON
56
0.60
0.43
34
25
10.5
9.0
