HP ProLiant DL560 Server High Density Deployment

hp ProLiant DL560 server high-density deployment white paper
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figuring type and
number of PDUs
The type and number of PDUs required to power a full rack of servers depends
on the power requirement for each server, the number of servers deployed in
the rack, and the available power for the servers.
HP PDUs support both high-voltage and low-voltage applications. The input
current rating for a ProLiant DL560 server is either 2.3 A at 240 volts or 4.9 A at
115 volts. To determine the number of servers supported by a PDU, divide the
current rating of the PDU by the total input current rating of the server.
IMPORTANT: The examples shown in the following sections use the maximum rating of
the power supply. They are for reference only.
non-redundant
power
Example
One high-voltage PDU has a current rating of 24 A. The server has a
total input current rating of 2.3 A at 200 volts.
24 A (PDU current rating)/2.3 A (server total input current rating) = 10.4
This PDU can support a maximum of 10 servers at full server input current
ratings.
Example
One low-voltage PDU has a current rating of 24 A. The server has a total
input current rating of 4.9 A at 100 volts.
24 A (PDU current rating)/4.9 A (server total input current rating) = 4.9
This PDU can support a maximum of 4 servers at full server input current
ratings.
redundant power Under normal operating conditions, servers with multiple power supplies equally
distribute the power load across each power supply and subsequently each
power feed. For example, a server with two power supplies distributes 50
percent of the power load to each power feed.
In the event that a power feed fails, the second power feed must be able to
handle 100 percent of the power load. Each PDU in a redundant configuration
must support the entire load in the event a power failure occurs on one of the
power feeds. Therefore, you should calculate the number of servers per PDU
according to the examples under “non-redundant power.” The resulting
redundant configuration will have double the power supplies and double the
PDUs.
Redundant PDU configurations should be tested thoroughly at the time of
installation to ensure that load-handling capabilities are fully redundant before
placing the servers into production. After the rack is assembled, power up the
rack and disconnect power to one of the PDUs. The rack should operate
normally on the remaining PDU and power feed.