Wago is better than sliced bread, the only people upset with them are just butthurt that their knowledge of how to use a wire nut is no longer a competitive moat.
It is much more convenient and I highly doubt anybody that can splice a couple of wires sees that ability as a means to keep the competition out. But there are drawbacks and you should be aware of them. When doing high current and tri-phase connections I will use a wire nut, otherwise I use a Wago.
Prove that. There is no evidence for that if they are used within spec - and if there was, UL and CSA would immediately pull their listings. There is however, plenty of FUD on the internet about Wagos being dangerous, even though plenty of tests have shown this is not true. For example, this test which showed a five-connector Wago running at maximum of rated limit releases about 1W of heat. A little warm, nothing dangerous.
https://www.youtube.com/watch?v=zgjo36-jaFY
https://www.youtube.com/watch?v=OhFwcEcNF2I
Also, you should look into how common electrical fires are in Germany if you really want to prove your case. Wago popularity over there is insane. Wire nuts are viewed as archaic and most homeowners don't even know they exist.
But Wago's really do have higher contact resistance (especially when they age), can have higher temps and I've personally seen more than one case of a molten Wago, including one where the whole metal part had molten its way out of the container, as well as one where the tabs had gone missing and were all locked in the 'open' position (no idea how that came to be).
I do a lot of house renovations, have installed a whole pile of solar gear (including some pretty heavy duty inverters), and have installed a complete machine shop. You're more than welcome to question all of that but I'm not in your pay and I don't need to prove anything, my personal experience is good enough for a forum comment. I use both, for where I think they are most appropriate and that's how I treat all tech: apply it for its strengths and be aware of the weaknesses.
I know that wire nuts can sometimes have a better failure rate when tested at much higher currents than either connector is rated for but this is equivalent of ingredients causing disease when you consume 1000 times more than is typical.
Or look at how romex/NM (doesn't) hold up to mild rodent activity.
I'm not saying that Wagos are in the same category as receptacle backstabs. The point is there are definitely quality/safety reasons to choose one approved method over another.
We had a mouse chew the romex going to the receptacle for our dishwasher (as well as the drain line). He must’ve gotten quite the shock, since the breaker tripped. The wire was charred and had exposed copper.
Motors and other large inductive loads are especially nasty in this respect, which is why there are several 'curves' in use for ground fault interruptors. The most common, the B curve will do a max or 3 to 5x for a short period of time before it kicks in, but a C or D curve can go much, much higher. And then that contact resistance (which wasn't such a huge problem so far) suddenly is a problem. Now you're generating serious Wattage in a small space that has no good way to get rid of the heat. Imagine an elevator motor or a shop lift or or something like that. This sort of application is where I would never use a Wago. But for regular low power stuff in my house I use them all the time, lights, bedroom outlets and so on. But my 17 KW Solar inverter is using crimped on joints and I checked the torque on the screws in the plug to make sure it's all up to spec. Those are not things to mess around with and hope it will hold.
If you want to have some fun take a FLIR across an older exposed installation, it will definitely help to visualize what contact resistance will do.
Wagos are hard to fuck up.
That's why wire nuts cause fires and wagos don't. If I had a dollar for every wire nut I've ever fished out of the bottom of an electrical box, I'd be able to buy a nice dinner for the whole family, whereas I'd leave the dollar store empty handed if someone had forced those numptys to use wagos.
> Wagos are hard to fuck up.
This we readily agree on, but I've seen both being fucked up enough to go over the electrical system with a FLIR for any new property purchase. The stuff you find like that you won't believe, including dead rodents, completely burned out junction boxes, arcing so strong that you could smell the ozone meters away from the junction box (essentially a matter of time), wire stripped bare over ridiculously long distances and so on. Other code violations such as using only black 1.5 mm^2 for a whole installation and non in-ground approved cable buried a couple of inches under a driveway.
My advice is to use both, each for their strengths. If you're wiring up an electric motor of any sizeable power I'd definitely do that using the best connection possible, so a crimped on screw terminal if that's a possibility, a wire nut if it isn't and a Wago if there isn't anything else. But I'd check the drop across the Wago before calling it a day, just in case. Start-up currents are pretty nasty. Also: anything behind a type C or D breaker.
Can't agree on this at all. You twist the wires together in the direction the nut threads on, then screw it on. After it's done give each leg a light pull to make sure it's secure.
Where and how are people fucking this up? I could see using the wrong size, leaving stripped wire outside the nut or stuffing way too many wires into one nut, but other than that I'm baffled.
- too small a diameter wire to properly engage the thread
- uneven insulation so only the tops get joined
- not enough twist so only the first couple of threads engage
- stranded wire cut through completely by the threads
- wrong kind of wire
(aluminum! which really needs its particular kind of connectors and is fortunately phased out but you may come across it in older installations).
- too many wires for the size nut (usually 5 is the max, depending on thickness)
- re-using oxidized wire ends because there isn't enough wire length
- wires not twisted at all before applying the nut
- leaving out the wire nut spring (!)
(presumably to make room for more wires...)
- spring upside down
- untwisting the nut and the spring, then untwisting the wires to add another splice
- bending the copper too often (metal fatigue)
- not inspected after twisting it on
- too much insulation stripped
- wire end damaged during insulation stripping
- wires twisted in the wrong direction
And so on... In comparison some of these will apply to Wagos but in general they have fewer ways of doing things wrong and adding another splice is much easier with a Wago. DIY electrical is great, it saves a ton of money. But the kind of stuff you come across can make your hair stand on end. The house I live in came with an electrical installation that was downright dangerous, I live here for 5 years now and I think I've fixed most of it but every now and then a new surprise pops up. Recently: a wall socket stucco'd over but before they stucco'd it over a piece of flex wire (twin strand) was connected through a groove cut into the wall to a brand new in-wall grounded socket of which the ground was left unconnected. Whoever made that (I suspect the previous occupant) is a complete idiot when it comes to electricity.