Which item can be used to verify CT polarity during installation?

• A. Envoy power supply
• B. CT sensor
• C. Solar panel
• D. Neutral and grounding bar

Answer: (B)

CT polarity matters because the current transformer defines the direction of current flow that the monitoring system uses to assign positive or negative readings. The CT sensor is the only item that directly defines and communicates this polarity to the gateway; it has labeling and wiring conventions for I+ and I−, and it is placed around a conductor to sense its current. To verify polarity during installation, place the CT around the conductor you want to monitor, wire it to the monitoring device, and energize a known load. If the display shows a positive value when current flows in the expected direction, the polarity is correct. If the reading is reversed, rotate the CT or swap its leads so that the measurement aligns with the actual direction. The Envoy power supply only provides power to the gateway, the solar panel is unrelated to CT polarity, and the neutral and grounding bar is used for safety and grounding rather than sensing polarity.