Wiring:The iWave-R includes a patented universal voltage 24VAC to 240VAC input ability. The black wire (marked ‘AC’ on label) is for 24VAC to 240VAC voltage enter. The white wire (marked ‘N’ on the label) is definitely the neutral leg for 24VAC or 120VAC; or another warm leg for 208/240VAC. https://charliengaqj.dm-blog.com/18432102/i-wave-an-overview