The main “in principle” complaint I’ve heard about the Wago’s is that the springs may lose strength with repeated heat cycles in high-current operation. This doesn’t apply when used with grounding wires or with most modern lighting systems. They’re especially convenient in older/smaller boxes. When putting newer larger devices into an older box, they may be the only alternative to ripping out the older box and sticking in a new one.
BTW, I’m referring to _actual_ Wago’s like the German-made 221, not the Chinese knock-offs or the “twisty-lock” push-in’s.
Last edited by Doug Dawson; 03-03-2021 at 11:35 PM.
Just by coincidence, a youtube popped up a couple of days ago that tested Wago vs wire nuts. The guy was running massive overcurrent through & measuring the temp rise. The Wagos did heat up a little more than the wire nut connections, but that was at something like 60A running through a 20A connector.
We think we know that something will fail, but until there is evidence of that, it's just a guess. To make an accurate assessment, one needs data and I haven't been able to find any that says a Wago is less reliable than a wire nut when used within the ratings. I don't think it can be argued that there is more chance of an incorrectly done connection with a Wago though. I'd love to see a study that compares the reliability of statistically significant numbers of both types of connections.
When I wired my new home under a homeowners permit I didn't twist the wires first. Inspector didn't have a problem with it. That was about 1975 when the prevailing wire nuts had a soft plastic coating, not the wingnuts like you see now. I have since found two that failed open with one short wire not engaging the nut properly. Since then I always twist them first. Now I have Klein lineman's pliers which work good. My good Knipex lineman's are now a handy dandy stripper after cutting a live 20 amp circuit that had a bad breaker that didn't trip. All breakers have since been replaced.
NOW you tell me...
If Wagos are approved to be used in code applications, I would expect that the manufacturer would have to provide documented extensive testing to prove their reliability. They are CSA and UL approved in addition to any testing documented by the manufacturer. Now do you push the wires in or stand on the other side and pull them in?
Never heard of Wagos until this thread. Here's the video I think Frank is referring to.
I had an electrical safety class years ago taught by a retired New York Power and Light construction supervisor. He said that NEC code required all connections had to be mechanically secure before the wire nut went on. That meant twisted. He had stories of electricians getting knocked off of ladders because of wires popping out of wire nuts.
I don't know if it's in NEC code or not but I've always twisted the wires.
-Tom
An issue with not twisting is that when there are more than a couple of wires, it can be tough to twist the wire nut on hard enough to make the twist & hold the nut on securely. the 'wings' on some help a lot, but if you don't have strong hands, you better be twisting with pliers.
I don’t think wire nuts are even permitted for use in UK or Continental Europe, all lever or screw terminal block connectors nowadays. The only downsides to Wagos that I can see are the cost and that they’re a bit fiddly to use with stranded wire.
Another advantage of Wagos - unlike wire nuts, you can actually see quite clearly whether you’ve got the wire end seated all the way inside the connector.
While working in transportation any wiring with high voltage or current would be spliced with crimp connectors using precision jaws and a pneumatic driver.I have made splices on loads as large as 2000 amps. These are all 3 phase, 480 volts. In every case the focus has always been on maximizing the surface contact between the conductors and making sure the connection is very tight. Loose connections always fail, eventually.
Do they make Wago connectors for such loads?
jtk
"A pessimist sees the difficulty in every opportunity; an optimist sees the opportunity in every difficulty."
- Sir Winston Churchill (1874-1965)