[jacquesm]

What a silly response. No, Wago has in some cases higher contact resistance than other means of splicing hard copper wire. And in those cases it can lead to an increase in temperature, arcing and possibly fire.

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.

[gjsman-1000]

> And in those cases it can lead to an increase in temperature, arcing and possibly fire.

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.

[jacquesm]

Wago's fail all the time, as do wire nuts. Both need to be applied properly. Applying a Wago properly is easier than applying a wire nut properly.

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.

[btbuilder]

Could you elaborate? All connectors regardless of type have current rating and specify what wire gauges they are compatible with. It seems like it would be a big deal if a properly installed Wago could catch fire.

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.

[mindslight]

Code and device approval are basically minimum standards. For example it's common wisdom to avoid "backstab" connections on receptacles, yet (at least one) NRTL keeps their approval, and they keep selling them. Go image search for "receptacle backstab" and see all the melted ones.

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.

[organsnyder]

> Or look at how romex/NM (doesn't) hold up to mild rodent activity.

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.

[jacquesm]

Wago use a spring loaded contact to touch the wire and there are at least two of these in series for every connection. This works quite well for currents up to about 20 A, and if the Wago is applied properly: straight wire, right thickness and proper length stripped. Obviously if you mess any of those up all bets are off. But assuming proper installation that 20A is still a potential issue: lots of gear has a multiple of that for a short time when starting up. That's when contact resistance starts to become important, and as connections age mechanical resilience comes into play and what was borderline before may become a problem. Contact resistance is ideally constant but as connections age they are pretty much a factor of how much copper is in contact with each other and this is where wire nuts do a better job. So a brand new Wago splice and a wire nut splice will probably have approximately the same contact resistance, but several years down the line it may well be quite different.

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.

[jjoonathan]

Wire nuts are easy to fuck up.

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.

[jacquesm]

> Wire nuts are easy to fuck up.

> 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.

[bbradley406]

> Wire nuts are easy to fuck up

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.

[jacquesm]

Here are some of the ways in which I've seen people mess this up:

- 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.

[aidenn0]

Just because you seem to have a lot of experience, any thoughts on the old-style grey Wago vs the new-style clear ones?

[jacquesm]

New ones for sure. Those stab-ins come loose much easier and are harder to get right. There are some stab-ins that are transparent, those at least allow you to inspect that the wire is seated properly. But be careful when you manipulate them to close a junction box because any twisting of the wire can cause them to slip loose.

[aidenn0]

Oh, I meant the gray 222s vs the clear 221s. The whole "I can see it right" thing is nice with the 221s, but I've had people tell me that the 221s don't hold as well as the 222s.

[jacquesm]

I couldn't tell you without bench testing them and that - done right, not just for youtube views and clicks - is a whole pile of work.