The insulation material on the stranded material may have a lower melting point in addition to less thermal mass. Just a thought.
I don't see them coming loose with the tape wrapped around them, but un-taped, the little tabs could release when one is pushing them around in the box. Most of those I've used are in "yuge" boxes which feed out to machine locations, so it's not a tight space. I'm not personally worried about them. A number of electricians around here use them and when I asked the electrician who installed my service, he offered no cautions.
--
The most expensive tool is the one you buy "cheaply" and often...
Given the number of failures of joints made with wire nuts I've seen personally over a couple decades of home renovations the Wago's would have to be pretty terrible to be worse. They seem less subject to user error in installation (I just received my first box of lever lock Wagos, haven't used any yet). There's a phenomenon with almost every new technology where someone's uncle's brother in law heard of a failure of the new product and now everyone thinks it's junk. The introduction of PEX would be a good example, or the utter nonsense that circulates about electric cars. Of course the stories of polybutylene and cPVC water pipes might be a good counterexample. The lever connectors have been used since 2003, if they failed at an unusual frequency I think the NFPA/code folks would have noticed by now.
A few weeks ago, I lost a ballast in one of the 15, 4 bulb T-8 lights in my shop. When I replaced the ballast, I discovered the Wago connects. In my 40+ years servicing everything from radars used in air traffic control to CT and MR scanners, I used a lot of twist on connects. I like the Wago connectors!
Last edited by Ken Fitzgerald; 07-12-2023 at 7:45 PM.
Ken
So much to learn, so little time.....
My friend is an electrician and uses them all the time. He says they are great for tight places and are code approved. We used them in my shop for the 240V because they are a lot cleaner when wiring 10 or 8 gauge wire. They're not coming lose any more than a properly installed wire-nut with the ends pre-twisted beforehand.
I disagree with this- stranded wire wrapped under a screw head is a mess and tinned is better. Likewise tinned stranded wire is better in a wire nut or in a crimped connector (but matters less there).
I've used Wagos and have somewhat mixed opinion. Good for switch boxes (they take up less room, not more), and fine for connecting a light fixture, but they are basically the same mechanism as push in connections on the back of household switches and receptacles, which while approved, are the cause of many electrical problems and something that I never use.
(I am an electrician- well, general contractor with 45+ years in electrical)
The missing strands that were cut in stripping is not a factor, IMO. Wire connections in switch boxes often get compromised from pushing the wires back into the box, especially if they were not planned to go in without stress. I never tape wire nut connections- just makes a sticky mess and doesn't add anything. Never see it in professional installations. Since your load is up there & there's been a problem, it would be good to check the current draw- lots of clamp on units around for borrow or buy.
While I agree with never using push-in connections on switches and outlets, Wagos are not quite the same. While you "can" use them as push in, if you flip the lever, you can easily insert the bare wire end and then put the clamp in place positively so it bites as it's supposed to do. The wire remains nearly pristine. You do have the advantage of disengaging a wire if you need to by flipping the lever to release it. Of course, that's also why I recommend taping them, too.
--
The most expensive tool is the one you buy "cheaply" and often...
Roger, I believe the device failed internally increasing the resistance resulting in high amperage needed to provide required amperage out to lights. I base this on a situation back in the 1990's on a Chiller feed with 4/0 wire to a circuit breaker, factory provided on the Chiller. The insulation melted back on the wire feeding the circuit breaker, one of three, the wire leaving the circuit breaker was never damaged. I had installed 3 split core current switches per control drawings. Once the chiller ran for less than a day, I had to use a hammer to break the melted plastic cases to remove the current switches. Only after the circuit breaker was changed out did the wire remain undamaged. there was a measurable voltage drop thru the circuit breaker when the chiller was operating.
To me it looks like the failure was a really cheap and undersized wire nut. Note that the wire nut that failed is smaller than the others in the box. Most likely it was the wire nut supplied with the switch intended for connecting the switch to a single wire, not gripping the three wires of the connection.Attachment 504137 Attachment 504138
Lee Schierer
USNA '71
Go Navy!
My advice, comments and suggestions are free, but it costs money to run the site. If you found something of value here please give a little something back by becoming a contributor! Please Contribute