Wiring:The iWave-R features a patented universal voltage 24VAC to 240VAC enter capacity. The black wire (marked ‘AC’ on label) is for 24VAC to 240VAC voltage enter. The white wire (marked ‘N’ on the label) may be the neutral leg for 24VAC or 120VAC; or another warm leg for 208/240VAC.Highest temperatures have been recorded across the nation