Potential electrocution hazard!
This procedure should only be attempted by a certified electrician.
Why is this important?
The most common installation issue with retrofit energy metering is known as a phase mismatch, which will cause incorrect power calculations and often lower-than-expected power factor. In addition, the power readings may be the opposite of expected polarity (based on CT orientation).
It's extremely important to verify correct phase-matching between CTs and associated line voltages when making power calculations using a retrofitted energy meter.
Method for verifying phasing on a CT:
Step 1: Using a handheld voltmeter set for the voltage of the system, place one probe on the L1 voltage terminal of the eGauge and the other probe to the conductor the CT is around.
Step 2: Check the Voltage reading between the two points. A reading of 0 VAC means they're on the same phase, while a reading of 208 VAC (or other phase-to-phase voltage) means they're on different phases and the conductor the CT is around is not landed on L1. Check the monitored conductor against L2 and L3 and look for a 0 V reading.
Step 3: For each installed CT repeat the steps above and record the CT + Line Voltage pairs where a 0 VAC reading is noted for use in the configuration portion of the setup.
