To verify wire phasing, two measurements are taken: L1 at the main breaker and L1 at the Envoy's power terminal block. If phasing is correct, what should the readings be?

• A. 240 volts, 0 volts
• B. 0 volts, 120 volts
• C. 0 volts, 240 volts
• D. 120 volts, 120 volts

Answer: (C)

Phasing checks confirm that the Envoy is connected to the correct hot leg relative to the main service. In a typical 240/120 V split-phase system, the two hot legs are 180 degrees apart. When you compare the L1 point at the main disconnect with the L1 point at the Envoy’s power terminal block, a correctly phased install places these two L1s on opposite legs. That means, with respect to the same reference (like neutral or ground used during the test), one measurement will show essentially 0 V and the other will show about 240 V. This 0 V / 240 V pattern indicates the two L1 points are on opposite phases and the wiring is correct. If both readings were around 120 V or both were near 0 V, that would signal a phasing issue.