Power Quality Logger

Methods of Logging

Current Logging

The maximum values of the currents (L1 or A, L2 or B, L3 or C, and N) are measured, and the interval value of the current is calculated using the mean value over the RMS values of the interval defined in PQ Log.

Logging Function A

If a 3-phase current sensor is connected, the neutral current is calculated on a sample basis from the phase currents. If a 3-phase+N sensor is detected, you can select between logging and calculating the neutral current in PQ Log.

Ipeak

The peak values of the current (samples, not RMS values) are averaged in the PQ Log software over the predefined measuring interval.

Note

Short peak values do not contribute much to the average value, and so Imax can be higher than Ipeak.

Crest Factor (CF)

The crest factor (CF) of the currents (L1 or A, L2 or B, L3 or C, and N) is the ratio of current peak value divided by current RMS value, and is averaged over the interval length defined in PQ Log. For sinusoidal signals: CF = 1.41, and for square waves: CF = 1.00

Power

The power values (L1 or A, L2 or B, L3 or C and N) are averaged over the interval length, and the maximum value of each is recorded.

The response time can be set to 1 second or 1 minute, and is independent of the response time for voltage and current.

In logging function P, the active power, apparent power, and reactive power of the phases and total power of all three phases is calculated.

Logging function A also calculates the distorting power D of the phases, and

Dtotal.

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