Can a 3 Phase Data Logger Be Used for Single Phase?

We often get asked the question, whether our 3 Phase Data Logger instruments can be used with Single Phase circuits, and particularly whether they can be used to monitor multiple single phase circuits at once. The question arises because the instruments have 3 Current Transformers and 4 Voltage Probes, which would appear to be enough to monitor 3 separate single phase circuits.

3 Phase Configuration

LDW-6092K 3 Phase Data Logger

LDW-6092K 3 Phase Data Logger.

Normally these instruments are used for monitoring one 3-phase circuit. In this case your electrician would put one Current Transformer (CT) around the current carrying cable on each phase, and would connect the voltage probes to the three phases plus the neutral. Press the “1ø3ø” button repeatedly to switch the instrument’s mode until it displays “3P/4W” at the bottom of the screen.

Single Phase – 1 Circuit

If you only want to measure one Single Phase circuit, then the instrument is relatively easy to set up. Ask your electrician to put the L1 current transformer around the current carrying wire to be measured, and to connect the V1 voltage probe to the active, and the N voltage probe to the Neutral. Press the “1ø3ø” button repeatedly to switch the instrument’s mode until it displays “1P/2W” at the bottom of the screen.

Now you can see the instantaneous measurements on the screen. If you want to record the data, we recommend following the tips in this blog post: 9 Tips for Successful Data Logging .

Single Phase – 3 Circuits

If you have 3 different loads on the same phase (or on different phases), all drawing different currents, and the phases have a common neutral return or common ground, then you can monitor them using our 3 phase data logger. 

Ask your electrician to put the three current transformers around the current carrying wires in the three circuits. Connect the V1, V2 and V3 voltage probes to the phases that correspond to the circuits you’re measuring (which may be all the same terminal if it’s all one phase). Ensure the N voltage probe connects to the Neutral.

Press the “1ø3ø” button repeatedly to switch the instrument’s mode until it displays “3P/4W” at the bottom of the screen. Note that this is the same mode as the 3-phase configuration above. The only difference is that you need to ignore several of the measurements reported by the instrument. All the “voltage difference” measurements are meaningless (e.g V1-V2 etc), and all the “summation of phases” measurements (such as PΣ and WH) are meaningless in this scenario. However the individual phase measurements are all OK and can be relied upon, and these are the measurements that one would require when monitoring 3 separate single phase circuits.

Now you can see the instantaneous measurements on the screen. If you want to record the data, we recommend following the tips in this blog post: 9 Tips for Successful Data Logging .


About Chris Dobbie

Chris Dobbie is an experienced Systems Engineer focused on Industrial Technology. As the owner of Esis (Sydney, Australia) he has had exposure to a wide range of industrial electronic equipment in a variety of applications, and also has extensive system design and C/C++ programming experience. Contact Chris if you want to chat about your project!

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