I have a situation that I have never run into: the customer is asking for multiple ways to control the lights in a large complex. This is what they want.
- first the simple part: 1 photocell that will turn on all the contactors at one time.
- second: be able to turn on any one contactor without turning on the others (this is for maintenance of individual areas during the day). I figured simple enough, use a 3-way or 3-position switch on all the contactors so I can have them all on photocell and can switch to manual control with any switch to the contactor of choice.
- now they want the big part: also be able to turn on any individual contactor with a remote computer or phone. They have the relays to do it.
But the question is how to keep them all separate. If I tie the relay to the photocell side, then they all will come on. If I tie to the manual side then they would need to flip the switch to manual, meaning the remote from the phone would be useless.