Section 150-619-100
Revision 01
Page 6
4.23 The Maximum Power Dissipation measures
the power that is converted into heat buildup within
the unit. It contributes to the total heat generated in
the space around the unit. It is used to determine
the maximum number of fully loaded shelves per
bay that does not exceed the maximum allowable
power dissipation density in Watts/sq. ft.
4.24 In Central Office locations, the maximum
power dissipation for open-faced, natural convection
cooled mountings is limited to 120 Watts/sq. ft. per
Section 4.2.3 of the NEBS standard TR-NWT-
000063. The footprint of a 28-slot 23-inch HLU-619
shelf is 7.024 sq. ft. Therefore, the maximum bay
dissipation is limited to 840 Watts. At 7 Watts per
slot, this limits the number of loaded HLU-619 slots
to 120 per bay.
4.25 Insert the heat deflecting baffles between
every other shelf to reduce excess heat build-up.
4.26 To determine the thermal loading limitations,
apply the HLU-619’s power parameters to the
manufacturer’s requirements for each specific
housing.
4.27 The Maximum Power Consumption is the
total power that the HLU-619 consumes or draws
from its -48 V shelf power source. This parameter is
important when the HLU-619 is remotely located to
its serving CO. It determines the battery capacity
required to maintain an 8-hour standby battery
reserve for emergency situations; this limits the
maximum number of plugs per remote enclosure.
Use the above data to perform this analysis on a
case-by-case basis.
4.28 The Maximum Current Drain is the
maximum current drawn from the shelf power supply
when it is at its minimum voltage (42.5 V). It
determines the shelf fusing requirements. All HLU
shelves are partitioned into two equal halves. Each
half should be fused at 10 A for a total of 20 A per
shelf. A fully loaded shelf draws 10.5 A worst case.
This is within the 20 A fuse limit.
4.3 USING THE RS-232 CONNECTION
4.31 A female 9-pin (DB-9) RS-232 connector is
provided on the front panel (see Figure 3). This
connector provides asynchronous access to the
HiGain-2 system maintenance provisioning and
performance monitoring software. The port is
configured as DCE with 8 data bits, 1 stop bit and no
parity. You can connect an ASCII terminal or a
Personal Computer loaded with or using
communication software.
5. USING ALARMS
5.01 Pin H is the HLU-619 minor alarm (MNRALM)
output pin, which replaces the Local Loss of Signal
alarm on normal High Density (3192) repeaters. Its
normally floating output can connect to pin 1 of the
1184 or 3192-9F Alarm Card in position 29 of the
High Density (HD) shelf. This pin must never be
taken above +5 V or below -60 V. The HLU-619
forces pin H to +5V (maximum of 10 mA) for any of
the conditions listed below. More than one alarm
condition can exist at any one time, but only one
message can be displayed. For multiple alarms,
only the highest priority alarm is displayed. The
alarms are listed in their order of priority:
ALRM LOSW
The VHDSL loop lost sync
ALRM LLOS
Loss of HLU DSX-1 input
signal
ALRM RLOS
Loss of HRU DSX-1 input
signal
ALRM TLOS
A user option that causes the
loss of the HRU DS1 input
from the NI to initiate a logic
loopback in the HRU.
ALRM HES
VHDSL loop has exceeded
the 24-hour selected Errored
Seconds CRC threshold.
ALRM DS1
The total number of bipolar
violations (BPV), at either the
HLU or the HRU DS1 inputs,
have exceeded the 24-hour
selected threshold.
ALRM MAL
The margin on the VHDSL
loop has dropped below the
minimum threshold value set
by the RS-232 terminal
Margin Alarm Threshold (see
Section B Paragraph 9.09).
