The two black wires are attached to the trans transformer terminal on the doorbell unit and to the front or front doorbell terminal.
Front trans rear doorbell wiring.
Usually the chime unit has screw terminals that are labeled front rear and trans which indicate the front doorbell wire rear doorbell wire if you have one and transformer wire respectively.
The wire from the front door push button goes to terminal 2 marked front ignore the terminal marked trans.
Adding a second doorbell chime.
Connect the input wires on the transformer to the source circuit using the black to black white to white and ground to green method.
Try turning on lights in the area to make sure the power is shut off.
Typically doorbell chimes have three terminals labeled rear trans and front that correspond with each connection.
Loosen the screw terminals and disconnect the wires.
If you have hardwired doorbell buttons at the front and back of your house and one of them works you can be sure that the non working button or the wiring connected to it is bad.
For instance if you re wiring a doorbell to your front door flip off the switch that controls power there.
The wire from the rear door push button goes to terminal 1 marked rear on the doorbell.
Locate the doorbell transformer in the outlet box near the door.
The color of the wire doesn t matter.
Wiring diagram for a two chime doorbell.
Terminals on the bell unit are marked front back and trans for transformer.
Located on the central hub of a doorbell chime the doorbell terminals are where the wires from the doorbell push button s and transformer connect to the chime.
A spool of 18 gauge wire is available at hardware stores and home centers.
Depending on which doorbell you are replacing will decide if you need to use the front or rear connector but you will need to use the trans connector.
The second black wire comes from the doorbell button.
One for the front door the other for the back door.
Many doorbell units make two sounds.
Wiring for two doors is the same as for one with the transformer hardwired to the 120 volt source from a house circuit.
A doorbell transformer is an electrical component that literally transforms power from a higher.
One wire from the transformer goes to the trans terminal and one wire from each button goes to either the front or back terminals.
The rear terminal is where the rear doorbell push button if you have one connects to the chime.
Use tape to label these wires accordingly so you can remember which is which.