I’ve read enough bad things about backstab connectors on household light switches and outlets that I’m prepared to go through my house and change over any backstabbed connections I find to screw or clamp terminals.
The claim is that backstab connectors - the kind where you strip the wire and jam it into the back of the switch/outlet, and it’s retained by a spring-loaded backward-facing barb - result in a crappy high-impedance connection that’s prone to heating, arcing, and (in the worst cases) fire.
If backstab connectors are so bad, are they code-legal? If they are, why?
I haven’t heard anything bad about backstab connectors (but I believe you). When I finished my basement in 2009 I used theseinstead of wire nuts. They are the reverse barb you described in the OP. That said, the type of metal, amount of contact area, etc could be significantly different.
Personally I wouldn’t bother rewiring all of your outlets and switches. If one of your terminal screws is (or works itself) lose, you’ll be in the same arcing boat.
I have had good luck with wire nuts, when I use my own procedure:
Strip ends of wires.
Tightly twist the stripped ends of the wires together using a pair of duckbill pliers.
Screw on wire nut using fingers. Make sure it’s the right size wire nut, and make sure it’s on tight.
Grab a couple cable ties and wrap them around the insulated portion of the wires. One cable tie should be very close to the wire nut, and the other should be about one inch away from the wire nut.
They basically work, if done right. There are plenty of backstab connectors out there that aren’t causing problems.
That said, there are an awful lot of them that do cause problems, and as an electrical engineer my personal opinion is that they shouldn’t be allowed by code. I think they are a horrible idea. I will never have backstab connectors anywhere in my house, and if I moved into someplace that had them I would remove them ASAP.
If anyone in any thread ever mentions backstab connectors the first thing I do is tell them to get rid of the things (assuming someone else doesn’t beat me to it).
ETA: I personally wouldn’t use the push in connectors that TheBori mentioned either. I use wire nuts, basically the same as Crafter_Man except that I don’t bother with the wire ties at the end.
I have a friend who is an electrician and he says that properly done there is nothing wrong with backstab connections, except that he sees many that aren’t properly done. He also complains about DIYers that can’t properly strip wire, nicking it which can be a great way to cause heat and arcing. I prefer clamps myself but I’ve done plenty of screw terminals. Many new outlets have only the choice between clamps and backstab. Wire nuts are quick and simple. I always wrap them in electrical tape when I’m done. Proper stripping is needed also.
Years ago I was renting and had an outlet stop working. I threw the breaker, removed the plate from the wall and found craziness. Someone had twisted wires together for the connection, then wrapped it in a shit-ton of masking tape.
I was due to move out anyway, so I just mentioned it to the landlord and kept that particular breaker tripped.
backstabs can damage the wire and do not allow inspection of the connection. later movement of the device (receptacle or switch) can worsen the connection or damage the wire.
I recently brought and installed a new fluorescent fixture, and the connection to house power was designed to use “quick connect” push in connectors, similar to the ones linked to by TheBori (two part connector, you push the striped ends of the mains’ wire into their respective holes in one part of the connector, and then snap the two parts of the connector together). The reason I mention this is: I have read such quick connects are supposedly becoming common (standard?) on new fluroescent fixtures for simplicity and safety reasons (my particular connection was a Wago, 873 like this, designed with the capability of wiring fixtures in parallel), so unless the OP plans to start snipping off these connections when installing new lights, he may as well get used to them.
As overkill, even though they were nice and tight, properly inserted, and correctly stripped to the right length, I still covered the wires I inserted with liquid eletrical tape for added safety - I’d rather not worry about wires shorting out either.
That’s my feeling also, as an electrical engineer and electrician. There’s probably a reason do you don’t see backstab connections on circuit breakers.
I would never use backstab connections, and don’t think they should be allowed. It’s not always easy to change the wiring though. In my experience, someone who’s likely to take the shortcut of using a backstab connection is also likely to take the shortcut of cutting the wires short (which makes it easier to stuff back into the box), and probably nicked the wire when they stripped it. All that together makes it tough to redo.