Schneider Electric iEM3200 Manuale Utente

106

DOCA0005EN-04

Power, energy and power factor

iEM3100 / iEM3200 / iEM3300 series user manual

Energy delivered (imported) / energy received (exported)

The meter interprets energy delivered (imported) or received (exported) according to the direction of
real power (P) flow.

Energy delivered (imported) means positive real power flow (+P) and energy received (exported)
means negative real power flow (-P).

Power factor (PF)

Power factor (PF) is the ratio of real power (P) to apparent power (S), and is a number between
0 and 1.

An ideal, purely resistive load has no reactive components, so its power factor is one (PF = 1, or unity
power factor). A purely inductive or capacitive load no resistive components, so its power factor is
zero (PF = 0).

True PF and displacement PF

The meter supports true power factor and displacement power factor values:

•

True power factor includes harmonic content.

•

Displacement power factor only considers the fundamental frequency.

PF lead / lag convention

The meter correlates leading power factor (PF lead) or lagging power factor (PF lag) with whether the
current waveform is leading or lagging the voltage waveform.

Current phase shift from voltage

For purely resistive loads the current waveform is in phase with the voltage waveform. For capacitive
loads, current leads voltage. For inductive loads, current lags voltage.

Current lead / lag and load type

Quadrant

Real (P) power flow

Energy delivered (imported) or

received (exported)

Quadrant 1

Positive (+)

Energy delivered (imported)

Quadrant 2

Negative (-)

Energy received (exported)

Quadrant 3

Negative (-)

Energy received (exported)

Quadrant 4

Positive (+)

Energy delivered (imported)

P
S

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Current and voltage in phase (resistive)

Current leads voltage (capacitive)

Current lags voltage (inductive)

270°

90°

270°

90°

270°