ADC H2TU-C-388 Manuel D’Utilisation

Page de 66
152-388-100-02, Issue 2
 
Appendix A - Specifications
H2TU-C-388 List 1
June 6, 2000
 49
P
OWER
 C
ONSUMPTION
The maximum power consumption and heat dissipation depends upon the type of remote units in the system and 
the CPE power setting.
The three most important power parameters of an H2TU-C are its maximum power consumption, its maximum 
power dissipation and its maximum current drain. 
 describes line-powered circuits on 9 kft, 26 AWG loops.
M
AXIMUM
 P
OWER
 D
ISSIPATION
The maximum power dissipation measures the power that is converted into heat that builds up 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 per square foot to comply with GR-63.
In COs, the maximum power dissipation for open-faced, natural convection-cooled mountings is limited to 
134.7 watts per square foot per GR-63-CORE. The footprint of a standard 28-slot, 23-inch HMS-317 shelf is
7.024 square feet. Therefore, the maximum bay dissipation is limited to 946 watts. Use this limit and the 
parameters in 
 to determine the maximum number of H2TU-C circuits that can occupy one CO bay. 
The thermal loading limitations imposed when using the H2TU-C in a Controlled Environmental Vault (CEV) or 
other enclosures are determined by applying its power parameters to the manufacturer's requirements for each 
specific housing.
The -48 Vdc power consumption is the maximum total power that the H2TU-C-388 consumes or draws from the 
shelf power source. This parameter is needed when the H2TU-C-388 is in a location remote to the CO it is serving. 
It determines the battery capacity required to maintain an 8-hour, standby battery reserve for emergency situations. 
Battery capacity, therefore, limits the maximum number of line units which can be installed in a remote enclosure. 
Use the data in 
 to perform this analysis. 
M
AXIMUM
 C
URRENT
 D
RAIN
The maximum current drain is the maximum current drawn from the shelf power supply when it is at its minimum 
voltage (-42.5 
Vdc
). This determines the shelf fusing requirements. Use the -42.5 Vdc current data in 
 to 
determine the shelf fusing requirements for your particular H2TU-C applications.
Table 18.
H2TU-C-388 Power Parameters
-48 Vdc Power 
Consumption 
(Watts)
Heat Dissipation 
(Watts)
-42.5 Vdc Current 
(mA)
Remote Power Source
Maximum
Maximum
Maximum
Line powered
12.5
7.0
294.0
Local powered
5.0
5.0
117.0
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.