[jmckenna]

I have a boat dock that has three lamps on the dock that are controlled by a photoelectric sensor. the lights run parallel along the water side of the dock. The photoelectric sensor is mounted in the second light's fixture.

The photoelectric sensor has 3 wires - one black, one gray/green and one white. The box has 4 wires - black, white and 2 blue.

How should the wires be connected?

Thanks for your help.

 

[mpoulton]

There's no way to tell based on the information provided. We'd need to know what the wires in the box go to. It's not even clear that it's possible to install the photoelectric sensor in that box. Was there one installed there before? If so, just connect the new one the same way - they are pretty much universal. If not, why are you installing it there instead of at the beginning of the run where power enters the first light?

Unrelated but important: is this circuit GFCI protected either at the breaker or at least before the power reaches the dock? Dock wiring is dangerous, and there is absolutely no good reason not to have ALL OF IT GFCI protected before power even reaches the shoreline. These kinds of things happen often, and are preventable: http://wqad.com/2015/07/10/lake-of-the-ozarks-death-motivates-east-moline-families-to-make-a-change/