Back Stab Receptacles

[LarryFine]

I've seen enough problems with stabbed connections that I won't let anyone who works for me do it. I see stabbing as also risking a dollar to save a dime.

 

[PetrosA]

The more expensive Hubbles have a back stab of sorts in that you can install the wire from the back but you are screwing it down in the terminal. These connections are very reliable. But the receptacles are expensive.

Ooooohhhh, I disagree. They may be more reliable than a spring clip back stab, but it VERY easy to strip the screw when you back screw (?) one of those Hubbels with a single wire.

 

[LarryFine]

Ooooohhhh, I disagree. They may be more reliable than a spring clip back stab, but it VERY easy to strip the screw when you back screw (?) one of those Hubbels with a single wire.

Then you're over-tightening them, and I can say that, having a gorilla grip myself. Just like most GFCI terminals, they're very reliable.

 

[LawnGuyLandSparky]

I've seen enough problems with stabbed connections that I won't let anyone who works for me do it. I see stabbing as also risking a dollar to save a dime.

I have a home that had devices that had NO screws - backstab ONLY. (Except the ground screw)

 

[brantmacga]

I saw one old salt rebel against the #14 limitation. He actually drilled out the holes in the back of the new devices so that #12 would fit in there ...

I had an electrician tell me that one of his coworkers forces #12 into the #14 backstabs.

 

[LawnGuyLandSparky]

I had an electrician tell me that one of his coworkers forces #12 into the #14 backstabs.

Sounds like foreman material...

 

[JohnJ0906]

I have a home that had devices that had NO screws - backstab ONLY. (Except the ground screw)

When I started in the trade (1990) I remember using the receptacles that had 4 backstabs per side, no screws.

 

[PetrosA]

Then you're over-tightening them, and I can say that, having a gorilla grip myself. Just like most GFCI terminals, they're very reliable.

I'm sure I over-tightened them, the problem though is that if I wrap the wire around the screw, it takes way more torque to strip the screw than if you have a wire cocking the rear plate. I did it once, and those recepts are now together with GFCIs on my list of "around the screw only" devices

 

[roger]

I'm sure I over-tightened them, the problem though is that if I wrap the wire around the screw, it takes way more torque to strip the screw than if you have a wire cocking the rear plate. I did it once, and those recepts are now together with GFCIs on my list of "around the screw only" devices

Do you also strip breaker screws that utilize presure plates?

Roger

 

[tkb]

The more expensive Hubbles have a back stab of sorts in that you can install the wire from the back but you are screwing it down in the terminal. These connections are very reliable. But the receptacles are expensive.

That would be "back wire" not "back stab".

As far as I know there are four types of connections for a switch or receptacle.

1. Side wire - screws on side
2. Back wire - screws with pressure plates
3. Back stab - hole to insert wire with a spring clip
4. Plug tail - wires for a splice that plugs into the back of device

I prefer the back wire type.

 

[George Stolz]

Funny this should come up, I recently changed all the devices in a home where all the connections were backstabbed, and had remarkably few failures related to it. They were the devices without screws on them at all.

As I worked my way around the house, I was kinda chuckling to myself, thinking I would start a thread about it, saying how that house didn't have a problem. About that time, I pulled out a receptacle that by all rights should have smoked itself - the conductors looked gorgeous, but simply slid right out of the back of the receptacle as I pulled it out of the wall.

Sometimes, lightly loaded circuits don't fail despite favorable conditions to fail, I guess.

 

[PetrosA]

Do you also strip breaker screws that utilize presure plates?

Roger

That design is different. In the breaker, you have the plate floating below the screw head and the threaded plate is stable, so no shear force is applied. In the recepts, the threaded plate is what floats, so it takes very little pressure to shear the brass threads in it.

 

[don_resqcapt19]

That design is different. In the breaker, you have the plate floating below the screw head and the threaded plate is stable, so no shear force is applied. In the recepts, the threaded plate is what floats, so it takes very little pressure to shear the brass threads in it.

Assuming that the thickness of the threaded plate is the same, then the torque required to strip the threads will be the same. It really doesn't matter which piece is fixed and which piece is floating. I don't really see much in the way of shearing forces here...they are mostly in tension.

 

[satcom]

The Back Stab Receptacles issue is easy, after many years of doing service calls, we found, the number one problem would be, trouble with a back stab Recptacle. I think they are great, they make plenty of work for us, if they stopped using them, our service call work load would take a hit.

 

[roger]

Assuming that the thickness of the threaded plate is the same, then the torque required to strip the threads will be the same. It really doesn't matter which piece is fixed and which piece is floating. I don't really see much in the way of shearing forces here...they are mostly in tension.

I agree with Don and another problem with the screw being stripped would mean that the torque specs that come with the device are not being followed.

That design is different. In the breaker, you have the plate floating below the screw head and the threaded plate is stable, so no shear force is applied. In the recepts, the threaded plate is what floats, so it takes very little pressure to shear the brass threads in it.

I have a Hubbell Spec Grade receptacle in my office right now that has a floating plate under the screw the same as a breaker does.

Roger

.

 

[ultramegabob]

I saw one old salt rebel against the #14 limitation. He actually drilled out the holes in the back of the new devices so that #12 would fit in there ...

just how did that save any time or labor?

 

[PetrosA]

Assuming that the thickness of the threaded plate is the same, then the torque required to strip the threads will be the same. It really doesn't matter which piece is fixed and which piece is floating. I don't really see much in the way of shearing forces here...they are mostly in tension.

Recept in question was a 30A 120V twist-lok. I hadn't even applied as much force as I would to a 15A duplex when the thread crapped out. The difference in shear force is that the screw itself becomes a fulcrum, and the thread on the wire side and that opposite are taking the bulk of the pressure. If the wire is twisted, or two wires are inserted, then the force is evenly applied to the entire thread.

I agree with Don and another problem with the screw being stripped would mean that the torque specs that come with the device are not being followed.



I have a Hubbell Spec Grade receptacle in my office right now that has a floating plate under the screw the same as a breaker does.


Roger

.

Or, the material specs were not followed... It really didn't take a lot of force (screw was still tightening easily) to break the thread.

The one I had had a threaded plate floating inside the recept like a GFI

 

[Power Tech]

Thanks for all the info. I used to run service in the LA area for years. Seen just as many problems with side wired as back stabbed. And yes, I did find many stranded wires back stabbed, also stranded wrapped around the screw.

 

[-=PEAKABOO=-]

If it has the means for it, and generally they only allow for #14 solid copper.

But I wouldn't recommend it - 90% of the service calls I go on where someone is reporting a section of lights and/or plugs in their house that stopped working, it usually winds up being a receptacle or switch with a back-stap connection that went south. I don't trust them and I always wrap the wires on the screws.

That is strange, I rarely see this as a problem unless someone is running a window ac unit, 1500 watt heater etc. etc.

Usually when the issue is due to an issue with a receptacle that has been "stabbed" it is because the wire was not inserted into the actual connector but only into the plastic hole or the someone stabbed the wire into the release part next to the proper hole.

 

[-=PEAKABOO=-]

Oh. Well I was talking about receptacles.