True or False: When setting up the consumption CTs, you can use the L1, L2 measurements to aid you in determining potential installation errors with the CTs?

• A. False
• B. True
• C. Not applicable
• D. Not sure

Answer: (B)

The idea is to use the actual currents on the two live conductors to verify that the consumption CTs are installed correctly. When you set up CTs around the hot conductors for each leg, the readings on L1 and L2 should correspond to the real loads on those legs. By checking how the two phase currents behave, you can spot installation mistakes such as a CT being placed around the wrong conductor, around multiple conductors, or with incorrect polarity.

If everything is wired as intended, L1 and L2 will reflect the true current on each leg and will respond to changes in load on that leg. A mismatch—like one leg showing little or no current while there is noticeable load on that leg, or readings that don’t align with how the house is actually drawing power—signals an installation issue with the CTs. If the polarity is off, rotating the CT or correcting the orientation will bring the readings into correct relation with the actual currents. Using L1 and L2 measurements in this way provides a practical check to ensure the CTs are measuring the intended conductors and that the monitoring system will give accurate results.