Backstabbing 15a receptacles and switches

[ChargedUp]

Why does UL rate and approve this method when using 14awg wire and Leviton manufacturers this if it's frowned upon? (please don't say money) Where are all the class action lawsuits against this method?

I hear all the stories but from my own experience I find it hard as hell to pull the conductors out unless of course putting a ton of pressure on the release pin. Are screwed terminations being torqued to spec on 15a circuits? I doubt it.

I also realize the surface area argument but these are rated for 15a otherwise UL wouldn't approve. I'm not powering anything that requires more than 12a.

Please prove me wrong with solid technical evidence other than stories passed down through thousands of years and the ol' "I would never use them because I've been doing it the 'proper' way and that's what I've been taught and I'm not going to change and I've seen or heard the evidence first hand of failure" (without potentially knowing all the causation variables).

If we are talking about larger circuits other than 15a, then I understand the argument. In closing, why is something so common and widely available UL approved and manufactured if it's going to kill someone by causing a house fire?

 

[Hv&Lv]

UL approved it and I’m sure their testing was more rigorous than real world circumstances.

Probably everyone here has seen a backstabbed switch or receptacle that was burnt. Especially in the late 80s early 90s.
Probably everyone here has seen a breaker burnt due to loose wire terminations, or a meter base or panel main that was burnt up due to loose connections.

Also those nice stab connectors that are supplied in the new can lights now. How many here has been up in a hot attic to cut them out and wire nut the terminations after one or more stop working...

The point is, things go wrong with new Style terminations AND old style terminations. All methods can cause a fire if something goes wrong.
Backstabbing has been proven to be a proper installation technique by a listing agency. I see no problem with it.




That being said, I don’t do it in receptacles, switches or the manufacturer supplied connectors. I don’t like to go back for free...
it’s just my preference.

 

[MAC702]

I've been paid a few thousand dollars over a few years' time to diagnose and fix burned up backstabs. And since I've yet to see it burn down a house, keep doing them....

 

[LarryFine]

Generally, I'll replace a stabbed device with stabs as a troubleshoot, unless the stabbing was the issue. On a new job, I use the screws or clamp-type back-wiring.

 

[hbiss]

Just remember, UL tests and approves AFCI breakers. We're waiting for class action lawsuits but don't hold your breath.

As for backstabs vs screws or plate type clamp terminations, with screws and clamps the connection is in plain sight so the only variable is not tightening it properly which can cause heating. With back stabs,all you have to do is stick the conductor in the hole and a low resistance contact is made, right? UL tested it? So how come any of them burn up?

Statistics and experience shows that backstabs have a higher incidence of overheating than receptacles with other terminations. Keep in mind also that backstabs are only available on the cheapest residential grade devices that are the least likely to have large loads (equal to their rating) connected to them.

-Hal

 

[oldsparky52]

My house was built in 1980. I purchased it in 1998. In 2012 I had new floors and inside paint plus new kitchen counters installed. In the process, I decided I would replace the receptacles and switches just as a precaution. The old receptacles were backstabbed and the new ones I installed were also backstabbed. I've never had a problem with any of these devices. The biggest continuous load on any 15-amp circuit is a TV that is rated 400 watts. (watch, now that I've typed this, I'll have a problem, ) .

I installed thousands of these in the mid 70's (back stabbed) and I think we had 2 service calls on any of our work. It would be interesting to know if the devices that had a problem had a conductor that was not inserted far enough. One thing I always did was give a slight pull back to be sure the device grabbed the conductor.

 

[kwired]

The connection is pretty reasonable on a new device.

20 years later is when the spring pressure against conductor isn't that strong anymore and the connection fails.

20 years later sometimes screw terminal connection fails also.

Same goes for breaker to bus connections, terminations of service/feeder conductors, etc.

The receptacle is often fine for most applications, but plug something in that draws heavy current for long periods of time (like a portable space heater) and that is when it fails pretty quickly. That failure may not even be the supply termination, could be the receptacle to plug connection or even a failure in the cord cap and heat is transferred to receptacle.

 

[PaulMmn]

With a screw or plate clamp-- the heating and cooling as the load cycles off and on will probably loosen a connection just as much as an aging spring in a back-stab...

I -like- plate clamps! No more curling the wire around the screw (in only the clockwise direction), maybe using a needle-nose to scrunch the loop closed tight, then tightening the screw...

 

[MAC702]

...I installed thousands of these in the mid 70's (back stabbed) and I think we had 2 service calls on any of our work...

When the failure happens ten+ years later, no one calls the installing electrician. The current residents call a troubleshooting electrician and he fixes it for you.

 

[oldsparky52]

When the failure happens ten+ years later, no one calls the installing electrician. The current residents call a troubleshooting electrician and he fixes it for you.

So, how long is your warranty?

I've seen back stab failures and I've seen side screw failures. It happens. I've never had one in any place I live. Maybe that's because I don't load them up? IDK. I just know I've not had any problems.

So, do I get any commission for the service work created from back stabbing?

 

[oldsparky52]

The connection is pretty reasonable on a new device.

20 years later is when the spring pressure against conductor isn't that strong anymore and the connection fails.

20 years later sometimes screw terminal connection fails also.

Same goes for breaker to bus connections, terminations of service/feeder conductors, etc.

The receptacle is often fine for most applications, but plug something in that draws heavy current for long periods of time (like a portable space heater) and that is when it fails pretty quickly. That failure may not even be the supply termination, could be the receptacle to plug connection or even a failure in the cord cap and heat is transferred to receptacle.

I think I've seen you write this before. Oh, and I agree.

 

[M_J_C]

To answer the original question, when U.L. or whichever listing agency approves a product that has passed a standards test, the product is deemed safe for the use intended and meets the currently accepted standard.

The listing in no way implies that the product is more efficient, longer lasting, or better/worse than any other product that has passed the test and gained an approval rating.

The same can be said of NFPA 70, as good responsible electrical contractors we will strive to provide a superior end product to our clients, not just the absolute minimum required by the code. For instance, we can supply and install the least expensive panelboards, switches, and receptacles, but if we are in the business for the long haul, we will educate the client, and demonstrate the difference between a .89 cent receptacle and one that costs $6.89. We can improve energy transfer efficiency and lower the POCO bill by increasing branch circuit conductors one AWG size.

The point is, a listed product met the minimums, is that what we should strive for?

 

[oldsparky52]

The point is, a listed product met the minimums, is that what we should strive for?

If the customer doesn't want to pay for the upgrade, you have three choices. Eat the cost of the upgrade, install the listed "minimum" product, or don't do the work.

 

[cpickett]

To answer the original question, when U.L. or whichever listing agency approves a product that has passed a standards test, the product is deemed safe for the use intended and meets the currently accepted standard.

The listing in no way implies that the product is more efficient, longer lasting, or better/worse than any other product that has passed the test and gained an approval rating.

The same can be said of NFPA 70, as good responsible electrical contractors we will strive to provide a superior end product to our clients, not just the absolute minimum required by the code. For instance, we can supply and install the least expensive panelboards, switches, and receptacles, but if we are in the business for the long haul, we will educate the client, and demonstrate the difference between a .89 cent receptacle and one that costs $6.89. We can improve energy transfer efficiency and lower the POCO bill by increasing branch circuit conductors one AWG size.

The point is, a listed product met the minimums, is that what we should strive for?

In industrial applications when you're talking about a large motor that runs 24/7, sure, but in a residential application would the savings (if any) amount to anything?

 

[ChargedUp]

Thanks for the responses. To M_J_C's last post, yes I understand the NEC is a minimum standards guide, not a design guide, and also the function of UL listing. I'm not a licensed electrician. I went to home depot and bought the preferred receptacles by Leviton and wired them in my house. If we are talking about circuits larger than 15A with high load, then I would agree backstabbing may not be best practice. But for 15A receptacles with cell phone chargers, TVs, lamps etc, even a heater for that matter, pulling less than 12A, I do not see the issue with using the quick connect ports that the manufacturer provided and UL approved, nor inefficient energy transfer, etc with such small loads.

Yes, there is always going to be something better with everything in life, but for the amount of comments on the web stating that back-stabbed receptacles are less than adequate, doesn't seem to line up with manufacturer and UL.

Screw connections can loosen and fail as well if not installed properly. Even if you pigtail around the screw, the connection can still loosen, and resistance can build up. And we also don't know what any given receptacle was exposed to in it's past life...was the faulty backstabbed receptacle in question connected to a fully loaded surge protector with 6 devices on it, etc.

Thanks again for the posts.

 

[MAC702]

...I'm not a licensed electrician. I went to home depot and bought the preferred receptacles by Leviton and wired them in my house. If we are talking about circuits larger than 15A with high load, then I would agree backstabbing may not be best practice. But for 15A receptacles with cell phone chargers, TVs, lamps etc, even a heater for that matter, pulling less than 12A, I do not see the issue with using the quick connect ports that the manufacturer provided and UL approved, nor inefficient energy transfer, etc with such small loads.

...

Screw connections can loosen and fail as well if not installed properly. ...

The underlined keeps getting brought up. Of course it's true. And the ratio is about 300:1 in the experiences of my wife and myself, both licensed electricians for twenty years each.

 

[hornetd]

Thanks for the responses. To M_J_C's last post, yes I understand the NEC is a minimum standards guide, not a design guide, and also the function of UL listing. I'm not a licensed electrician. I went to home depot and bought the preferred receptacles by Leviton and wired them in my house. If we are talking about circuits larger than 15A with high load, then I would agree backstabbing may not be best practice. But for 15A receptacles with cell phone chargers, TVs, lamps etc, even a heater for that matter, pulling less than 12A, I do not see the issue with using the quick connect ports that the manufacturer provided and UL approved, nor inefficient energy transfer, etc with such small loads.

Yes, there is always going to be something better with everything in life, but for the amount of comments on the web stating that back-stabbed receptacles are less than adequate, doesn't seem to line up with manufacturer and UL.

Screw connections can loosen and fail as well if not installed properly. Even if you pigtail around the screw, the connection can still loosen, and resistance can build up. And we also don't know what any given receptacle was exposed to in it's past life...was the faulty back-stabbed receptacle in question connected to a fully loaded surge protector with 6 devices on it, etc.

Thanks again for the posts.

UL does not in fact "Approve" anything. They list devices and assemblies in the Building Materials List if the item conforms to an industry standard for that item. UL does not write the standards. UL tests for compliance with a standard. All the listing asserts is that the item complies with a specific standard. There are undoubtedly thousands of items which were once listed in the Building Materials List which would not test successfully to presently accepted standards.

Are you aware that the "Back Stab" receptacles are now only listed for #14 American Wire Gauge? The side mounted terminal screws, if provided, are listed for #12 AWG as well as #14. Initially the spring terminals were listed for both gauges. Since they had to be made with a hole large enough for the larger gauge, but were mostly used for #14 wire, they allowed #14 to move too much as it expanded and contracted from the regular cycling of various loads going on and off. The presently manufactured spring terminal receptacles will not pass the listing standard if the holes into the terminal are large enough to except #12 wire. The smaller hole forces the #14 conductors to remain in position under the contact spring. There is no longer any room for them to shift out of full contact. The spring configuration has also been altered to provide more contact area with the conductor. No conductor movement and a larger contact area equals adequate real world performance. The new ones are much better than the old dual gauge type but the truth is that until they have provided 20+ years of service without a significant number of failures I won't trust them so I won't use them.

I am retired out of both the electrical craft and fire and rescue service. With 5Ø+ years of electrical installation experience on 3 continents I have seen how the earlier versions of several devices did not stand the test of time. Towards the end of my active electrical work I avoided early adoption of new technology as if it were bubonic plague. I never regretted not being a test technician for the latest and allegedly greatest speedier to install device or luminaire.

--
Tom Horne

 

[M_J_C]

In industrial applications when you're talking about a large motor that runs 24/7, sure, but in a residential application would the savings (if any) amount to anything?

The POCO metering device generally uses CT's at the service entrance point to measure how much $$ is passing through, the greater the voltage drop at the point of use, the more current the device uses (generally, but not always) to achieve its rated output. Ever notice a motor that has a two amperage ratings, one for 230V and and one for 208V? The same is true for most loads, as voltage drops, current goes up, not to mention incidental heating of the structure, something we don't need in the south!. Here are some references:
https://www.ecmweb.com/electrical-testing/minimize-voltage-drop-upsizing-your-conductor-size
https://www.copper.org/environment/...y-efficiency/education/archive/onesizeup.html
https://www.energy.gov/sites/prod/files/2014/04/f15/motor_tip_sheet8.pdf
https://iaeimagazine.org/magazine/2009/07/16/energy-loss-global-warming-and-voltage-drop/

 

[MAC702]

... Initially the spring terminals were listed for both gauges. Since they had to be made with a hole large enough for the larger gauge, but were mostly used for #14 wire, they allowed #14 to move too much as it expanded and contracted from the regular cycling of various loads going on and off. The presently manufactured spring terminal receptacles will not pass the listing standard if the holes into the terminal are large enough to except #12 wire. The smaller hole forces the #14 conductors to remain in position under the contact spring. There is no longer any room for them to shift out of full contact. The spring configuration has also been altered to provide more contact area with the conductor. No conductor movement and a larger contact area equals adequate real world performance. The new ones are much better than the old dual gauge type ...

Thank you very much for this. I will start looking for the difference when I see these from now on. I did notice that receptacles I buy would only accept #14 in the stabs, but I hadn't noticed what the old ones were like.

 

[Hv&Lv]

The POCO metering device generally uses CT's at the service entrance point to measure how much $$ is passing through, the greater the voltage drop at the point of use, the more current the device uses (generally, but not always) to achieve its rated output. Ever notice a motor that has a two amperage ratings, one for 230V and and one for 208V? The same is true for most loads, as voltage drops, current goes up, not to mention incidental heating of the structure, something we don't need in the south!. Here are some references:
https://www.ecmweb.com/electrical-testing/minimize-voltage-drop-upsizing-your-conductor-size
https://www.copper.org/environment/...y-efficiency/education/archive/onesizeup.html
https://www.energy.gov/sites/prod/files/2014/04/f15/motor_tip_sheet8.pdf
https://iaeimagazine.org/magazine/2009/07/16/energy-loss-global-warming-and-voltage-drop/

That’s some funky math on some of those articles... not enough information to achieve some of their results.
It makes sense the copper industry says to upsize the wire. Their figures are with a 15 amp load running continuously. Plus everything else in the house... you can afford that, $17 more ain’t gonna hurt you...