wiring
#1
04-12-03, 07:07 AM
wiring
My house was built in 1968.The wiring has three wires .One is black one is white one is red.Which is the hot and which is the ground?
#2
04-12-03, 08:25 AM
Member
The red and black are both hot, either on the same leg of the power or on opposite legs, depending on what the wiring you are looking at is used for. The white is neutral. None are ground -- you may or may not have grounding through metal conduit.
Give us more information about why you are asking and what changes you are considering and we might be able to provide more help.
Give us more information about why you are asking and what changes you are considering and we might be able to provide more help.
#3
04-12-03, 08:47 AM
wiring
I am planning to install a dimmer switch in my dineing room.There are 2 switches in the room.Each switch controlls the light in the ceiling.There are 4 wires out of the dimmer switch.2 red 1 black one green.How do I connect these to the 3 wires in the box?
#4
04-12-03, 08:59 AM
Member
Hopefully, you have not yet removed the old switch.
What you have is two travelers and a common. All three wires are hot. The white wire is not a neutral as I previously guessed.
Before disconnecting the old switch, turn off the breaker and pull it out. Look carefully to see which of the three wires is connected to the common terminal. The common screw is usually black in color and/or you may see the marking "COM" on the back of the switch next to one of the screws. Mark this wire somehow before removing the wires. Then disconnect just the three wires connected to the old switch. If there are other wires in the box, leave them alone. Do not disconnect any more than you have to to get the old switch out.
The new dimmer should also come with markings or directions telling you which wire is the common. You will connect this to the wire connected to the common on the old switch. You will connect the other two non-green dimmer wires to the other two wires that your old switch was connected to.
If the box that this switch goes into is metal, attach the green wire to the box with an approved grounding screw (ask for one at your home center). If the box is not metal, simply cap or tape off the green wire and do not use it.
What you have is two travelers and a common. All three wires are hot. The white wire is not a neutral as I previously guessed.
Before disconnecting the old switch, turn off the breaker and pull it out. Look carefully to see which of the three wires is connected to the common terminal. The common screw is usually black in color and/or you may see the marking "COM" on the back of the switch next to one of the screws. Mark this wire somehow before removing the wires. Then disconnect just the three wires connected to the old switch. If there are other wires in the box, leave them alone. Do not disconnect any more than you have to to get the old switch out.
The new dimmer should also come with markings or directions telling you which wire is the common. You will connect this to the wire connected to the common on the old switch. You will connect the other two non-green dimmer wires to the other two wires that your old switch was connected to.
If the box that this switch goes into is metal, attach the green wire to the box with an approved grounding screw (ask for one at your home center). If the box is not metal, simply cap or tape off the green wire and do not use it.
