Schneider Electric iEM3200 Power factor PF, True PF and displacement PF, PF lead / lag convention

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).

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)

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.

P

PF = --

S

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

Current and voltage in phase (resistive)		Current leads voltage (capacitive)			Current lags voltage (inductive)
V	Vb	V	Vb		V	Vb	Ib
	Ib		Ib	Ia
I	Ia Va
				Va			Va
	Ic	I				Ic	Ia
				Ic		I
	Vc		Vc			Vc

90° 270°

90° 270°

90° 270°

106 DOCA0005EN-04