Also, to ensure detection of a reversed phase sequence, C 1 =C 3, and R 1 =R 3; that is, the components in the third branch are identical to those in the first branch.The phase-sequence-detection ...

The Inverter Phase Check, an electronic indicator, can help contractors troubleshoot when an inverter-controlled a/c unit fails. The unit can pinpoint whether the compressor or inverter is faulty.