Power calculation, Assumptions, Power delivery device voltage discovery – HP Insight Control Software for Linux User Manual
Page 11: Power delivery device total capacity calculations
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Rack PDU
: Rack Power Distribution Unit - This represents the input power and multiple outputs to load
segments.
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Load Segment
: This represents each of the outputs of the PDU that can be monitored. HP PDU
Management Module discovers up to the Load Segment level of the power topology.
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Outlet Bar
: This represents the division of the load segment into multiple outlets.
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Outlet
: A circuit with one input and one output that can be monitored.
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Load
: The power consumer connected to the outlet. The load can be a system, enclosure, or
undiscoverable system.
Power Calculation
Assumptions
Insight Control power management assumes the following for calculating power:
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1-phase is treated as 1-phase NA/JPN (line-to-line). You cannot change this to INT 1-phase.
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The load factor is 1. So, VA and Watts units are the same.
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All loads are balanced.
Power calculation
The power calculation in general can be categorized as:
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Power delivery device voltage discovery
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Power delivery device total capacity calculations
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Converting watts to amperes
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Converting amperes to watts
Power delivery device voltage discovery
If you know the power hierarchy of a power delivery device, the missing voltages can be found during
discovery phase. Insight Control power management finds the missing voltages for 1-phase, 3-phase Delta,
and 3-phase Wye PDUs made up of 1-phase sub-circuits assuming the usage of the device is balanced.
If you know the input (line) voltage of the device, the output (phase) voltage of each sub-circuit is defined
as:
1-phase - The input (line) voltage
3-phase Delta - The input (line) voltage
3-phase Wye - The input (line) voltage / sqrt(3)
If you know the output (phase) voltage for the sub-circuits, the input (line) voltage of the device is defined
as:
1-phase - The output (phase) voltage
3-phase Delta - The output (phase) voltage
3-phase Wye - The output (phase) voltage * sqrt(3)
Power delivery device total capacity calculations
If you know the line current (lineCurrent), line voltage (lineVoltage), and type of phase for the device, the
total capacity of a power delivery device can be calculated using the following formulas:
For 3-phase Wye:
phaseVoltage = lineVoltage / sqrt(3)
phaseAmps = lineCurrent
phaseWatts = phaseVoltage * phaseAmps
TotalCapacity = 3 * phaseWatts
For 3-phase Delta:
phaseVoltage = lineVoltage
phaseAmps = lineCurrent / sqrt(3)
Power Topology
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