ask the electrician
Electrician Training Electrical Certification wiring recessed light fixtures Electrical Wiring Electrical Troubleshooting and Electrical Repairs wire outdoor light fixture Home Electrical Wiring Diagrams
wiring home generator and transfer switch wiring a 220 volt range cord outlet Wiring for GFCI Outlets Wiring Outlets and a Switched Outlet Wiring and Installing Ceiling Fans and Remote Controls wire dimmer switch wiring diagrams for switches wiring a dryer cord and 220 outlet circuit breaker panel
Electrical Wire and Cable

2 Wire and 3 Wire Cables


home electrical wiring By
Summary: Electrical Wiring Question:
How do you know when to use 12-2 versus 12-3, 14-3 versus 14-2. I keep on getting confused on when to use 2 wire versus 3 wire.

When to Use 2Wire and 3Wire Cables


Electrical Troubleshooting Question:
My question is, how do you know when to use 12-2 cable versus 12-3 cable, 14-3 cable versus 14-2 cable. I keep on getting confused on when to use 2 wire versus 3 wire.
Thank You,Matt W.


Hi Matt - Great Electrical Repair Question!
2 and 3 wire cables can have several uses such as home run power feeds going back to the panel, branch feeds, single switching, 3-way switching, 4-way switching etc. It all depends on what you are wiring and what the electrical application will be.

Circuits Installed from the Electrical Panel

2-Wire Circuit
A 2-wire (black and white with the ground) cable will be used for one hot and one neutral or one circuit.

3-Wire Circuit
A 3-wire circuit (black, red, white and the ground) cable can be used for feeding two circuits that will share the neutral and ground wire.

Multi-Wire Configuration
The 2 circuit multi-wire configuration requires that the black and red hots be attached to a two-pole circuit breaker that has a tie-bar so that these two circuits are not fed from the same buss in the panel.

This will ensure that the neutral wire load will be balanced and not become overloaded under normal circumstances.

Voltage Readings
The voltage reading from black to red will be 240 volts because they are attached one to the two separate busses or phases, but the voltage reading from black to white/neutral or ground will be 120 volts and the same for the reading for the red wire to white/neutral or ground.

Be Careful and Be Safe, never work on energized circuits!



Electrical Wiring Tips for Home Electrical Wiring Projects

Tripping Circuit Breaker, Outlet at a Wall Switch, Light Fixture without a Ground Wire, Help with Home Electrical Wiring Projects.

See more House Wiring Videos from Ask The Electrician:

Home Electrical Wiring Videos


Learn more with my Home Electrical Video Course:

Basic Home Electrical Wiring by Example


» You Can Avoid Costly Mistakes! «

Here is How to Do It:
Wire It Right with the help of my Illustrated Wiring Book

Great for any Home Wiring Project.


  electrical wiring  

Complete Guide to Home Electrical Wiring

Perfect for Homeowners, Students,
Handyman, Handywomen, and Electricians
Includes:
Wiring GFCI Outlets
Wiring Home Electric Circuits
120 Volt and 240 Volt Outlet Circuits
Wiring Light Switches
Wiring 3-Wire and 4-Wire Electric Range
Wiring 3-Wire and 4-Wire Dryer Cord and Dryer Outlet
How to Troubleshoot and Repair Electrical Wiring
Wiring Methods for Upgrading Electrical Wiring
NEC Codes for Home Electrical Wiring
....and much more.