Just installed a lighting contactor for parking lot lights at 480 volts. I used a 277 volt coil using the line 1 voltage of 277 volts to send thru a photo-cell on the line side. When the photo-cell is activated it would pull in the contactor on the load side, turning the lights on. When testing this after completion by putting the box over the cell to similate darkness, the photo-cell was blown apart after the lights had switched off for approximately 20 - 30 seconds. One side of the coil was connected to a common as well as the photo cell white wire being connected to the same common. Any ideas as to why it blew apart? Any suggestions for a remedy? Thank you.
Just finished a job like that. (see the job comes together thread of a few weeks ago.)Make sure that you are running the other side of your sensor to the neutral line. If it's not your putting 480 across the light cell. Sorry if I'm being elementry but you always double check yourself when the troubleshooting starts. Next question, where in the scheme of things is the light sensor? Is it in a building where you are pulling the power, or is it mounted to one of the light poles. If you have room for it I think I would recommend a transformer to take your control voltage down to 110 or less. That way the guy behind you changing the sensor doesn't get a rude suprise. Good luck, troubleshooting is always the fun part. Trainwire