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CT Sensors - More than one line through a sensor?
CT Sensors - More than one line through a sensor?

Possible to monitor multiple lines with a single sensor? Yes, with a few key points.

Updated over 3 months ago

Utilizing Current Transformers (CTs), the Vue: Gen 3 accurately measures the amperage or current flowing through circuit lines in your electrical panel. A crucial aspect of achieving precise measurements lies in the correct placement of these CTs, particularly in relation to the phase of power.

Correct Sensor Placement and Phase Awareness

When installing the Vue: Gen 3 Home Energy Monitor, it's essential to understand that each CT sensor is designed to measure current from a single line. Misplacement of these sensors, especially involving lines from different phases of power, can lead to inaccurate measurements due to phase angle conflicts.

Single Line per Sensor

- Recommendation: As a rule, each sensor should encircle only one line. This ensures the most accurate current measurement for that particular line.

Multiple Lines Through a Single Sensor: The Exception

- Same Phase Only: It is permissible to run multiple lines through a single sensor if, and only if, these lines are from the same phase of power. Under these conditions, the sensor will aggregate the total energy usage from all lines, displaying it as a single measurement within the Emporia app.

The Issue with Different Phases

- Avoid Combining Phases: Placing a sensor around wires from both Phase A (L1) and Phase B (L2) simultaneously is strongly discouraged. Such configurations result in measurement inaccuracies due to the cancellation effect caused by the conflicting phase angles of different circuits.

Amperage Limitations

Please note that there are standard amperage or usage limitations for the sensors:
- For the original Gen 1 model, the maximum is 50A per sensor.
- For both the Vue 2 and Vue 3 models, the side sensor can handle up to 75A in total.

Understanding these limitations is crucial to prevent overloading the sensors and to ensure the longevity and accuracy of your energy monitoring system.

Simplified Illustration: Phase A (L1) and Phase B (L2)

For a clearer understanding, consider the configuration of a single split phase panel, which is standard in most North American homes. Remember, sensors must not encircle wires from both Phase A and Phase B simultaneously to avoid the inaccuracies mentioned.

Breakers and Phases.png

Your Feedback Is Valuable

At Emporia Energy, our commitment is to empower you with comprehensive insights to manage your energy usage more effectively. This knowledge base is continually evolving, and your feedback is instrumental in this process. If you have suggestions for improvement or require further clarification on any points discussed, please do not hesitate to contact our Customer Support team. Your insights will aid us in enhancing the quality and utility of our guides, ensuring you have the information needed to make the most of your Vue: Gen 3 Home Energy Monitor.

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