We’ve been back-stabbed…
I’m not talking about the hurtful betrayal from an otherwise presumed friend.
But I am talking about the quick installation method of wiring an electric receptacle that many “production” contractors employ. It’s a method of installing a receptacle quickly and efficiently, and saves contractors time when wiring a home. After all, time is money!
Most 15 amp rated electrical receptacles (and even switches) manufactured today include or provide a couple options for connecting the conductor (electric wire) to the device:
- The traditional method of wrapping/looping the conductor around the side screw terminal and tightening the screw to the proper torque.
- Or “plugging” the stripped end of the wire into the proper hole in the back of the device.
Any layman can readily determine which method is easier and provides for more speedy production in a home full of literally hundreds of such electrical connections. It’s the latter method of course!
Commonly referred to as “backstabbing”, but also known as “quick tap” or “quick wire” methods, the wire end is stripped of insulation and inserted into a provided hole in the back of the device. Done! Mount the device to the wall and move to the next! The conductor is internally “pinched” in place by spring metal tension via an engineered piece of metal inside the device.
Manufacturers promote it and market the option as a benefit. Building codes and UL listings approve it. And contractors embrace it as a time and money saver! But this practice can result in dire consequences as can be seen below…
As a residential and commercial property inspector, I utilize my infrared thermal imaging technology to discover concerns which may otherwise be overlooked. Such a concern includes overheating electrical devices or components. This overheating is typically caused by two concerns…
- An overloaded electrical circuit
- Or a high resistance (loose) electrical connection
The latter is commonly observed on back-stabbed electrical receptacles and switches. As part of the inspection process, I scan surfaces within the home or building looking for thermal exceptions which require closer scrutiny. A “hot” receptacle or switch is just one of these thermal exceptions. Especially if said receptacle has no visible load on the circuit (appliances or devices plugged in)
In the image, the arrow points to a “warm” receptacle in a vacant property. The dotted box highlights the apparent route of the electrical wire down the wall to the receptacle.
Upon closer examination we can see the apparent temperature of the receptacle at 98.3°F.
But this is only an “apparent” temperature and does not accurately depict what is occurring beneath the cover plate.
On a recent service call, a Dayton area client described intermittent power loss at a kitchen counter receptacle. Having identified a warm receptacle, we removed the cover plate and the screws securing the device to the wall. Pulling the device away, one of the neutrals pulled free from the back-stab and revealed a potentially catastrophic detail.
The exposed conductor had been arcing inside the device at the spring metal clip where it had been back-stabbed. Temperatures had elevated enough to scorch the wire insulation, and the conductor itself was damaged. (image right)
To note, prior versions of model building codes (National Electric Code) allowed 20 amp circuit receptacles to be back-stabbed with 12AWG (American wire gauge) conductors. This practice is no longer permitted under current revisions of the model code…. but still permissible for 15 amp circuits with 14AWG conductors. Apparently a 12AWG back-stab makes for a weak (high resistance) connection whereas a 14AWG back-stab does not. It’s been my experience that what holds true for the larger wire gauge is also true of the smaller wire gauge… regardless of what the model codes permit.
So I raise the question again… have you been back-stabbed? If so, be aware of the potential hidden hazards within your walls! It may be prudent to have your electrical system and components inspected just to make sure all is in order.