Home inspector flagged multiple neutrals on single lug in breaker panel

[ARCOgraphite]

Not unless they are a two pole breaker. Some Square D breakers may be designed to allow to wires, but it is NOT up to code. Everyone should have a current copy of Wiring Simplified if they are going to mess with electricity.

What is the NEC violation? The circuit branching hijinx the goes on inside 1 and 2 gang boxes around the home is the real threat. I had a smoking duplex a few years ago due to a branched circuit pigtailed to a backstab. That pigtail would get red hot at the pinch when loaded with a vacuum cleaner or portable heater.
I don't have any double-lugging in my load center, but I did find a 20A breaker installed by previous owner on a massively branched 14/2 circuit.. That is a house fire waiting to happen. Wire overheating.

 

[y_p_w]

Backstabbing is "fine" in the sense that it technically meets code, but it's not good practice and it opens the door for potential issues with loose connections. I think the fact that you can't backstab 12awg for 20A and grounds says enough. Going through my home's 40 year old wiring, I found many loose backstabbed connections that pulled right out without any effort. Unfortunately the new Decora Edge receptacles with the Wago style lever connectors weren't available at the time, otherwise I would've used those instead of J hooking and side screwing a billion wires...

I would definitely check receptacles that see high loads and make sure they aren't backstabbed. I would also address any daisy chained back stabs and pig tail those instead.

I've been redoing the backstabbed connections in a house and these are older ones (installed mid-90s) where the instructions say that 12 or 14 AWG are OK. Most of this was on a 20A circuit. But I've also been replacing some receptacles/switches for various reasons and the newer ones with backstab connections say "#14" is OK and the hole is clearly too small to accept 12 AWG. The istructions clearly state that 12 AWG should go in backwire clamps or screw terminals. It's weird too with a new Leviton Decora switch having a combination screw terminal backwire clamp and backstab holes.

As for backstab reliability, the big problem is that it's reliant on using the piece of brass for the contacts and the spring mechanism. Brass is a lousy . It should also only be used once, if at all. Just pressing into the release hole will permantly deform the spring, although it's also permanently deformed . A screw terminal can be reused indefinitely although I think it's probably better to not reuse a loop since soft copper makes for a better contact (like an oil gasket).

I'm kind of torn on backwires with a clamp. A lot of commercial grade receptacles/switches use them, but I'm not sure how secure they are long term. Many of these clamps seem kind of wide and I'm not sure how secure the wire can be depending on the location of the wire - especially 14 AWG.

Theoretically a new backstab connection should be at least as safe as the wire coming into it. The problem wouldn't necessarily be if it just pulls out completely since that would just break the circuit (other than a live wire touching ground or something else where it blows a fuse or trips a breaker). The big problem would be a marginal connection where there's a huge resistance and it just gets hot with a high load.

 

[atikovi]

Kind of doubt a large manufacturer would produce a dangerous product and risk liability suits over something as simple as this. I'm thinking that 50 years ago or whenever these first came out, all the old electricians got angry saying, how dare they come up with a new (easier) method of installing switches and outlets. It's can't possibly be safe. By golly we have been installing wires with screw terminals forever, this new push in system is just for the lazy electrician. And that mentality has stuck around. Same as how some plumbers insist copper is better than plastic for piping.

 

[SHOZ]

We used Hubbell at work and the backstab was tightened with the same screw as the outside terminal.

https://store.hubbell.com/product/158195