How to Properly Wire Terminals
To know the proper method of back wiring an outlet, you must know what type of back wire terminals the outlet has.
Two Types of Wire Terminals
There are two types of back wire terminals: Quickwire, and screw & clamp wire terminals. The back of the outlet will be labeled with the word “Quickwire” if the connection is Quickwire.
Which Type is Better?
Quickwire terminals aka “back wire” or “back stab” clamp the wire with only tension from a copper tab built into the contacts of the outlet. These tabs are not adjustable and have a high likelihood of getting loose over time if the following occurs: the wire is removed and reinserted, the outlet is not securely fastened to the wall, or the tab is subjected to excessive heat.
When the outlet is not secured to the wall properly and a plug is inserted and removed, it causes the potential for the wire to shift in the Quickwire connection, weakening the connection over time. A weak connection can cause excessive heat and/or arcing at the connection point.
Screw & clamp terminals
Screw & clamp terminals have an extra plate inside the outlet that is attached to the side screw terminal. When the wire is inserted into the back of the outlet and the side screw is tightened, it pinches the wire between two plates.
The screw & clamp terminal is a better alternative to the Quickwire terminal because the clamping force of the screw & clamp terminal will no fail from heat or outlet movement. Additionally, the screw & clamp terminal can be periodically checked for tightness and adjusted if necessary.
Important Tip for Both Terminal Types: Use the outlet’s built-in wire strip gauge to know if you’ve stripped the wire far enough to make a proper connection when back wiring an outlet. The gauge is always located on the back of the outlet, and looks like a rectangular box with some variation of the phrase “strip gage” or “strip gauge”.
Now that you’ve identified the correct type of terminal, ensured the wire is stripped properly, and know which side of the outlet the wire will be inserted into, insert the wire into the hole in the back of the outlet. Do the same for the other wire.
If the connection is Quickwire, all that needs to be done after pushing the wire in is to hold the outlet and pull the wire. This checks that the wire has a good connection and will not pull out of the outlet.
If the connection is screw & clamp, insert the wire and tighten the side terminal until it is tight. Then hold the outlet and pull the wire. This checks that the wire has a good connection and will not pull out of the outlet.
Now that electrical outlets are de-mystified and you have an in-depth knowledge of them, understanding when they are worn and need to be replaced will be much easier. Don’t forget, the single most important thing to do before repairing any outlet is to ensure the breaker is turned off and to double-check with an electrical meter that there is no power at the outlet.