On November 25, 2018 at 08:04, Ernie Gilman said...
A crucial point is that the Lutron note you linked to talks about a Lutron In-wall Sensor, while we're talking about an Occupancy Sensor Switch, that is, the sensor is buried inside the switch enclosure, with no access to the actual sensor wiring. As you saw, that means is no possibility of putting the SENSORS in parallel.
In the link to the Lutron Forum, the OP is asking the same thing you're asking. The responder says "no" by explaining what would happen if the 2nd switch is fed from the output of the first - not understanding the question where he wants to feed both switches with a hot wire and use both load wires for the load. The responders answer includes part numbers which match what I suggested - a wireless Maestro, a companion Maestro and a wireless occ sensor.
People normally don't put lighting and outlets on the same breaker, but I bet there will be complaints, and I can even see this product being recalled, if anyone ever installs a MS-OPS2H on a circuit protected by a GFCI. It should instantly pop a GFCI.
Yes, you would think that the small current flow on the equipment grounding wire would be enough to trip the GFCI. An ammeter and the GFCI specs would tell you.
Or am I wrong and lighting circuits must be separate from outlet circuits?
For dwelling units they are often on the same branch circuit unless it's a dedicated kitchen appliance circuit or laundry circuit for example. But general purpose outlets and lighting are typically together on a circuit. In commercial buildings it's a different story. This is because the lighting may be 277 volts. I don't believe the NEC prohibits this mix in commercial buildings but it's pretty much standard on every electrical drawing I've ever seen. That way, a short at an outlet doesn't leave the area in the dark. I suppose that could cause panic in a commercial space.
Did you ever see if the existing load is greater than 2 amps? If so then I would suggest the battery operated occ sensors and a wireless Maestro at one end and a companion Maestro at the other. The battery in the occ sensor lasts for ten years I think. You can install several of them to control the same switch.