Measurement

Settings

• Nominal values

  • Nominal frequency

  • Nominal current TDD L1..L3

• Current transformer

  • Channel name

  • Voltage reference

  • Swap s1(k) and s2(l)

• Current channel L1-L3

• Voltage transformer

  • Measuring mode

  • Connection

• Main measurement L1-L3

  • Primary

  • Secondary

Nominal values

Enter the nominal values of the mains to be measured here. These nominal values are required for the measurement and calculation of measured values.

Nominal frequency

Automatic: The measurement device can automatically determine the mains frequency if a sufficiently high voltage is present at the voltage measurement input V1: at least 20 V_eff for 4-wire measurement; at least 34 V_eff for 3-wire measurement.

If the measured voltage is not sufficiently high, the device cannot determine the mains frequency automatically and thus cannot measure it.

50 Hz/60 Hz: If the measurement device cannot determine the frequency (in the case of poor power quality, the sine wave of the voltage may be distorted to such an extent that double zero crossings occur, for example), you can set a fixed nominal frequency. If the frequency setting is fixed, the measurement device does not determine the actual frequency.

Nominal current TDD L1..L3

TDD stands for Total Demand Distortion and is similar to THD (Total Harmonic Distortion). TDD is a characteristic parameter for the harmonic current distortions that occur in relation to the maximum current of the system that occurs. To be able to calculate this characteristic parameter, you must set the maximum current that occurs in the system here. The measurement interval for TDD is 15-30 min. The characteristic parameter TDD is widely used in North America and elsewhere.

So while TDD refers to this fixed nominal current, THD is a dynamic characteristic for harmonic distortion in relation to the actual measured current.

• Enter the maximum primary side current that occurs in the system (nominal current under full load) in the input field and select the appropriate unit.

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Current transformer

In the device screen, click on a current channel L1..L3.

Channel name

Name of the current channel selected in the device screen.

Voltage reference

If you have swapped the current channel (e.g. L1 and L3 swapped), you can correct this here.

Swap s1(k) and s2(l)

If you have connected the current transformer of this channel incorrectly, you can correct this here.

Current channel L1-L3

The current transformers for channels L1 to L3 must have the same transformer ratio.

• Select the checkbox Current channel L1-L3.

• In the Primary and Secondary fields, enter the current transformer ratio according to the specification on the rating plate of the current transformer.

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Voltage transformer

In the device screen, click on a voltage connection L1..L3.

If you use voltage transformers, you must enter the transformer ratio.

Measuring mode

The Voltage transformer configuration card can be shown or hidden depending on whether you are working with or without voltage transformers.

• Click on a voltage connection L1-L3 in the device image.
  The Measuring mode drop-down list is displayed.

• To show the Voltage transformer configuration card, select Voltage transformer from the drop-down list.

• To hide the Voltage transformer configuration card, select Direct connection from the drop-down list.

Connection

If you have swapped the phases when connecting, you can correct the phase assignment here.

Main measurement L1-L3

The ratio of the voltage transformers must be identical for all three phases.

Primary

Specify the input voltage according to the rating plate of the voltage transformer.

Secondary

Specify the output voltage of the voltage transformers, i.e. the voltage applied to the measurement device at terminals L1-L3.

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