Appendix C - Functional Operation
150-231-165-01, Revision 01
50
September 22, 1998
HLU-231 List 6E
Power Consumption: With Doublers
One or two doublers may be used in the HDSL loops between the HLU-231 List 6E and HRU. See
for
general doubler deployment rules. This section addresses HLU-231 List 6E operation with the HDU-451 List 1,
2, 3, and 4 doublers, the HDU-437 and 439 mini doublers, and the HDU-404, 407, and 409 micro doublers. The
power consumption for the List 1 and 2 doublers is identical. The List 3 and 4 are low-power doublers, which
consume 40% less power than the List 1 and 2.
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 6E 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 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 and 4 doublers.
shows this CO current and other related power parameters for this
doubler application.
The maximum shelf current drain allowed is a function of the shelf -48 Vdc fuse.
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 the rated capacity of the shelf. Use
to select the
appropriate load fuses for the Building Distribution Fuse Bus (BDFB) when deploying the HiGain system
equipment in COs.
The maximum HLU-231 List 6E 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.
In CO locations, the maximum power dissipation for open faced, natural convection cooled mountings is 134.7
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 946 W. This limits the number of HLU-231 List 6E
units per bay to 90 when powering the List 1 or 2 doubler. This is a worst case situation since it assumes the entire
CO is subjected to the maximum power density. More favorable conditions permit increasing the number of
shelves per bay without jeopardizing CO thermal integrity.
M/M refers to the HDU-437 and HDU-439 mini doublers and the HDU-404, HDU-407, and HDU-409
micro doublers.
Table 16.
HLU-231 List 6E Power Parameters with HDU-451 Doublers (List 1, 2, 3, 4, and M/M)
60 mA CPE
Current
CO Voltage
Volts
CO Current Amps
Power Consumption Watts
HLU Power Dissipation Watts
List 1 & 2
List 3, 4, and
M/M
List 1 & 2
List 3, 4, and
M/M
List 1 & 2
List 3, 4, and
M/M
OFF
42.5
0.65
0.50
28
22
9.0
8.25
OFF
48.0
0.59
0.41
28
22
9.0
8.25
OFF
56.0
0.50
0.38
28
22
9.0
8.25
ON
42.5
0.80
0.58
34
25
10.5
9.0
ON
48.0
0.70
0.52
34
25
10.5
9.0
ON
56.0
0.60
0.43
34
25
10.5
9.0