Power Consumption; Maximum Power Dissipation; Maximum Current Drain - ADC H2TU-C-202 User Manual

LTPH-UM-1072-03
P C
OWER ONSUMPTION
The three most important power parameters of an H2TU-C are its maximum power consumption, maximum
power dissipation, and maximum current drain.
Table 26 describes line-powered and locally powered circuits on 9 kft, 26 AWG loops.
Remote Power Source
Line-powered
Locally powered
M P
AXIMUM OWER
The maximum power dissipation measures the power that is converted into heat and 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 in accordance with GR-63-CORE. The footprint of a standard 28-slot, 23-inch
HCS-417 shelf is 7.024 square feet. Therefore, the maximum bay dissipation is limited to 946 watts. Use this limit
and the parameters in
CO bay.
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.
The thermal loading limitations imposed when using the H2TU-C in a Controlled Environmental Vault (CEV) or
in 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 consumes or draws from the shelf
power source. This parameter is needed when the H2TU-C 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.
Perform this analysis using
M C
AXIMUM URRENT
The maximum current drain is the maximum current drawn from the shelf power supply when it is at its minimum
voltage (-42.5 ). This determines the shelf fusing requirements. Use the -42.5 Vdc current data in
Vdc
above to determine the shelf fusing requirements for your H2TU-C applications.
H2TU-C-202 List 2F
Table 26. H2TU-C Power Parameters
-48 Vdc Power Consumption
(Watts)
Maximum
12.0
8.6
D
ISSIPATION
Table 26 above to determine the maximum number of H2TU-C circuits that can occupy one
Table 26 above.
D
RAIN
October 25, 2002
Heat Dissipation -42.5 Vdc Current
(Watts) (mA)
Maximum Maximum
7.0 286.0
6.7 205.0
Appendix A - Specifications
Table 26
63