We have seen good results with those. It makes sure all wires are in contact. Some times one wire will slip out of a wire nut or slide some when twisted and not make good contact. The biggest problems we see with wire nuts is over tightening and the center wire breaks off. This is a bigger problem with the cheap help installing winged wire nuts with battery drills.

The simplest explanation....and correct me if I'm wrong...

If the box has one 12/2 in and one 12/2 out

Black = 2 white = 2 ground =1

for a total of 5....yes?

Correct.

Some additional notes...
If there are any devices (receptacles or switches) each device counts as 2.
Internal cable clamps and fixture mounting studs that attach to the back of a box (not too common any more) count as wire fill.
A wire that enters a box and leaves a box without a splice (can be done in conduit wiring) counts as one.
Pigtails do not count as a wire count.

I heard good things about those connectors too. They appear to be more substantial than the push-ins on devices that often fail. Ideal has the In-Sure push-in connector, another brand is Wago. As said, wire nuts don't always go on correctly. Installers are pressured by their bosses to get the job done quickly, so that sometimes means a less than perfect splice. If I start the pre-twist and something came out of alignment I will re-do it, but many people will just continue. Sometimes bad splices are due to lazy installers, sometimes its due to companies making installers do it as quick as possible to maximize their profits.
A perfect wire nut splice is as strong as it can be, but perfect or even acceptable can't be guarenteed. Those push-in connectors provide an acceptable connection almost every time. Over-stripping can still be a problem. I wonder if the moving of the wires when placing them back in the box will cause a problem, if the wire bends to the side when shoved back into the box. I use wire nuts but those push connectors appear to be getting more popular. Time will tell if there will be failures, but so far so good from what I hear.

I gave those push in things a shot. I like em. I also worried a conductor could come loose when pushing everything back in. I verified none of them did as best I could. You have to turn the conductor back and forth and pull at the same time pretty hard to pull one out so in my amateur opinion, it's not likely to happen.

At local big box stores here, the biggest push in wire nuts I could find are 4 port.

The link I gave above for the push in... $.31 a piece...but $9 shipping for first $20. I can get them from Ebay 2 for $3 includes shipping.... or Amazon box of 50 for $11 including shipping.

Not sure I'd ever need 50 6-port pieces...but you don't necessarily have to use all 6 ports, do you?

No and i think the box stores sell a mixture kit with some of each. I think I have a hand full of samples some where I will have to look.

Ray needs a road trip.

Yea right, you are closer to him then I am...

Pardon my ignorance (have been out of the game for a while), but are they static connection terminals that are screwed fast (can't see the back) or a flat strip of copper that bites down when pulled taut?

Also, is it easy to avoid hard 90 bends when they are pushed into the box?

They seem like a great idea, but are they a novel idea?

Thanks.

There are no screws. Just push the wire in and it holds it in place. I use wire nuts but I bought a small package of those connectors just to look at them. They do appear to be stronger than the failure-prone push-in holes on backs of devices. I keep those connectors with me for those situations when there is a short wire in the back of a box where there is no room to put on a wire nut.






Contractors are starting to use them since its quicker, and there will be no immediate call backs for non-working circuits (like there is when a wire slips out from under a wire nut). They don't care if they fail years from now. But from what I hear they are promising.