Phase wiring correction

Phase wiring correction puts the AC conductors at the inverter output back into the right order, so the inverter sees a positive A-B-C phase rotation. Use it when the inverter reports a reverse phase condition. In that state it is wired with the wrong phase order and will not run. On some large inverters, a negative A-C-B sequence stops the unit from running. A phase lock loop error or odd frequency and voltage readings are signs that the rotation should be checked. To fix it, an electrician swaps the positions of two phase wires at the inverter AC output terminals and then restarts the inverter. Swapping any two of the AC conductors reverses the phase rotation. Some inverters work with any phase rotation, but the local utility may still require a specific order or a record of it. A phase rotation test after connection is recommended. Other three-phase equipment, such as surge protective devices wired to a panelboard, also needs the A-B-C connection order kept during installation.