HP ProLiant DL380 Technical White Paper page 11

HP ProLiant DL380 Generation 3 Server High-Density Deployment
Table 4 demonstrates how calculating the derated input power of the system can significantly reduce
input current and thermal dissipation.
Table 4. Derated Current and Thermal Dissipation for Reduced input Power Assumptions
The derated input power values of the maximum and minimum configuration wattages can be
correlated with the measured input power values for the minimum and maximum configurations of the
server. However, the derated input power value must be high enough to account for any future
upgrades.
As stated earlier, the power supply is designed to support future processor and hard drive upgrades.
When installing 21 servers, the number of PDUs to be installed will depend on the support for the
input current requirement. Carefully derating the input power may very well satisfy the deployment
needs and reduce the numbers of PDUs per rack. Reducing the number of PDUs has a direct impact
on the deployment time and maintenance of an installation.
The remainder of this section explains the input power relationships to input current and thermal
dissipation to aid customers in derating the input power.
Input Power
Input Power at 115 VAC
Input Current at 240 VAC
Thermal Dissipation
Derated
Minimum Configuration Maximum Configuration
1.9 A 4.1 A
0.9 A 1.8 A
747 BTUs/hour 1560 BTUs/hour
Full Rating
4.9 A
2.3 A
1927 BTUs/hour
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