Application Examples

Power group overview

Most basic power group channels are also calculated in the power group realtime analysis. The power instrument only shows normal power group channels and cannot display the realtime channels. Any realtime channels is available in the channel list and can be used in other instruments.

A list of available channels is listed below figure Fig. 10.

Realtime OXYGEN overview

Fig. 10 Example of power group realtime channels on the measurement screen.

Setting up a 3-phase line-line power group

Figure Fig. 11 shows an example 3-phase line-line wiring. If the fundamental frequency gets detected based on the first voltage e.g. U1, the power values are calculated and can be previewed below the LOAD.

Realtime OXYGEN wiring

Fig. 11 Example of power group 3-phase line-line configuration

Power group settings

Efficiency tab

The first relevant tab for the power group realtime analysis is the Efficiency tab see figure Fig. 12.

  • DC power analysis requires an analog input for Voltage U_DC and for Current I_DC.

    • Create up to 6 DC power analysis and assign a DC voltage and current to each.

  • Mechanical analysis requires a analog input for the Rotational speed and for the Torque

    • Create up to 6 mechanical power analysis and assign a analog torque und speed intput to each.

Hint

The speed usually is a software channel, but for the realtime calculation a hardware input e.g. CNT 3/1 is required. The next figure Fig. 13 shows how to configure the counter input to be usable for the realtime calculation.

Realtime OXYGEN efficiency

Fig. 12 Example of power group efficiency tab with DC and mechanical efficiency

Configure counter for realtime speed input

Example how to set the counter input CNT 3/1 to be usable as the power group realtime speed channel is shown in figure Fig. 13.

  1. Change the counter mode to Frequency

  2. Set the unit to rpm

  3. Set the scalling to 60/(pulses per rotation), e.g. 4 pulse per rotation results in a scaling of 15.

Realtime OXYGEN speed via scaled frequency

Fig. 13 Example of speed via scaled frequency channel

Realtime tab

The final tab to configure the power group realtime calculation is shown in figure Fig. 14.

With OXYGEN 8.2 and higher, the AUX channels tab enables to include some additional analog inputs in the realtime output options.

Realtime OXYGEN Realtime tab

Fig. 14 Example of power group realtime tab