HP ProLiant DL380 Generation 3 Server High-Density Deployment 
 
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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 
Input Power  Derated  Full Rating 
  Minimum Configuration  Maximum Configuration   
Input Power at 115 VAC  1.9 A  4.1 A  4.9 A 
Input Current at 240 VAC  0.9 A  1.8 A  2.3 A 
Thermal Dissipation  747 BTUs/hour  1560 BTUs/hour  1927 BTUs/hour 
 
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.