lightingwiring
This picture is from a new building. It is not a 3-way light.
there are three black wires coming out from the wall. One runs directly to the light switch. Two get connected in the blue connector, and then one runs to the switch.
I can see the white neutral at the back.
Where is the ground?
And why are there three black wires?
I would like to replace this switch with a smart switch that requires neutral and ground connections.
Since you didn't provide a picture, or a very helpful description of what you're looking at. I'll try answering your question by explaining how the switch itself works, which will hopefully help you understand the problem better.
The pull chain switch that controls the light(s), is a single pole single throw (SPST) switch. It has two positions ON (Closed), and OFF (Open). Drawn simply, it would look something like this.
Switch shown in ON (Closed) position.
When the switch is in the ON (Closed) position, current is allowed to flow through the switch, through the light(s), and back to the the source (via neutral).
When the chain is pulled and released, the internal contact rotates 90° (1/4 turn) into the OFF (Open) position.
When the switch is in this position, current is not allowed to flow through the switch, and the light is not lit.
This is why the pull chain switch that controls the light(s) only has two leads.
The pull chain switch that controls the fan, is a single pole multiple throw switch. It has multiple positions, which allows it to control the speed of the fan. Draw simply, it would look something like this.
Switch shown in OFF (Open) position.
When the chain is pulled and released on this switch, the internal contact rotates 45° (1/8 turn) to the next position.
Another pull, another turn.
Pull again, turn some more.
One final pull brings the switch 180° around, and again to the OFF (Open) position.
By manipulating the output of this switch, the fan is able to whirl around at various speeds depending on the switches position. The number of output leads, will depend on the switch. How those leads are connected to the fan motor, will depend on the fan manufacturer. This simply illustrates the basic principle of how the switch works.
As always electrical work can be dangerous, never be afraid to contact a qualified Electrician
Turn off the breaker, undo both wires from the switch, then turn on the breaker. Get a NCVT (non contact voltage tester) and see which of the wires is hot. That will be the one back to the panel, the other one will be the load.
Yes, just connect the white to the other neutrals in the box, so they are all wire nutted together.
The programmable switch requires a neutral because it needs current itself all the time. If you just had the 2 black wires, there would be no current flow through the switch when it was off, so no way to power the electronics.
Best Answer
I see two ground screws on the metal junction box, and grond wires being affixed to both of them. Since there are three MC cables entering the box, either those screws support 2 ground wires per screw, or there is an invisible wire nut.