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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.

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.

Outlet Bar

: This represents the division of the load segment into multiple outlets.

Outlet

: A circuit with one input and one output that can be monitored.

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:

1-phase is treated as 1-phase NA/JPN (line-to-line). You cannot change this to INT 1-phase.

The load factor is 1. So, VA and Watts units are the same.

All loads are balanced.

Power calculation

The power calculation in general can be categorized as:

Power delivery device voltage discovery

Power delivery device total capacity calculations

Converting watts to amperes

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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