Why does Delta's Power Meter DPM measure a higher input current compared to a generic clamp meter?
When a current transformer, or CT, steps down a large current for measurement, errors may occur. The higher the CT step-down ratio is, the more significant the error can be. It is advisable to use solid core CTs for large current measurement to avoid errors. In addition, users can calibrate the DPM by adjusting the CT ratio for error correction.