ptonsparky
Tom
- Occupation
- EC - retired
That about right.
I was more concerned with the aluminum that was used on BC here for a few years.
Back stab receptacles
- Thread starter nizak
- Start date
I was more concerned with the aluminum that was used on BC here for a few years.
Since they’re 15A circuits, likely lighting, and with the low power requirements of LEDs, they’ll probably last forever.For the record, I love back stabbing devices.
I won't stop unless they're made unavailable.
For me it's a combination of ease of install, time of install, and longevity of finished product.
I mean, we don't think anything of a power tool failing after 10 years of daily use.
But let a back stabbed receptacle fail after 47 years and the sensationalists come unglued
James L
Senior Member
- Location
- Kansas Cty, Mo, USA
- Occupation
- Electrician
Biggest factor I've assessed is installer error. Namely, wires that are kinked or otherwise no straight, or jamming them in. Same with push-in Wagos
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I believe this is more a UL thing than a Code thing.
No. When they first appeared back in the 1970's I argued with fellow sparkies and told them when they approve back stab for ground wires I might use them. Only good thing devices now only accept #14 guage copper solid wire. I posted where I ran #2 copper THWN for two plastic injection machines that were made in Europe that had flimsy back stabs terminal strip for the 480 volt 70 amp load. I refused to use them and had the service tech install the wires. First machine burnt out the flimsy back stabs within a week.
I recall back stabs just one time when one of the teachers did them for school concert. That was around 1960. At that time we had 250Vac so maybe a bit risky for back stabs. I haven't seen them since.
Rick 0920
Senior Member
- Location
- Jacksonville, FL
- Occupation
- Electrical Instructor
What I find ironic is that I know guys that are against back-wiring of devices (I am too), but they use WAGO connectors instead of wirenuts. I've replaced a few melted WAGO connectors on 20 amp circuits. I agree that they have their uses. I love them for low amp applications like changing ballasts. But I feel they are the same as back-wiring a device.
kwired
Electron manager
- Location
- NE Nebraska
- Occupation
- EC
They are not the same. Back wired devices is all one piece design. The Wago's have a bus and a separate spring steel piece to provide contact pressure press conductor against the bus. They have more contact area as well.
ModbusMan
Senior Member
- Location
- Cleveland, OH
- Occupation
- Building Automation Engineer
- Location
- Tennessee NEC:2017
- Occupation
- Semi-Retired Electrician
I disagree! Back stabs are different in a few ways.
The clamping area is more and stronger on Wago (and other push-in brands)
With a backstabbed receptacle, the receptacle is pushed/pulled everytime something is plugged/unplugged. This can loosen the connection between the conductor and spring. Similar with switches
With a Wago, the splice is independent of the device, so pressure on the device doesn't cause any disturbance on the conductors.
I've used them for years with zero problems. Well I did have one problem, but that was installer error. I didn't push the conductor all the way in.
The newer Wago connectors are even better as they use spring levers to hold the conductor instead of just the push-in action.
I would wager that if you found a melted Wago on a 20A circuit, the conductors were probably not pushed in all the way, causing a loose connection and high resistance causing heat build up.
I've seen tests where a Wago was subjected to the same voltage and current as a wirenut. The plastic on the Wago melted a little sooner than the wirenut but was way more current then a 20A breaker would trip at. However,the metal connection to the conductor held up as good as the metal spring did in the wirenut.
kwired
Electron manager
- Location
- NE Nebraska
- Occupation
- EC
I been using them for probably at least 5 -8 years now. Had one lever nut fail in non dwelling application where it was subjected to what was likely a pretty high fault current passing through it. Breaker did trip but still was not all that far downstream from the service equipment and I'm sure the available fault current at that location was likely rather high. Other connection methods could possibly failed in this situation as well.
Haven't had any other failures I am aware of .
James L
Senior Member
- Location
- Kansas Cty, Mo, USA
- Occupation
- Electrician
I've seen Wagos melted for what I believe is the same reason that I've seen backstabbed receptacles melted. Number one issue I've seen is the people don't make sure the wire is straight. Whether it's curved or kinked or whatever else, they just shove it in there without any kind of thought.
But that's not necessarily an indictment against a push-in connection, because I've seen side wired receptacles and switches with the wire not stripped long enough. So the insulation is under the screw, the wire loop not tight enough so it's not around the post of the screw, the wire wrapped around backwards, the screw loose.... all kinds of installer issues.
At that first company I worked at, the one I mentioned earlier in the thread, there was a kid who started working there and he was super fast. We were still using those receptacles that would accept a backstabbed #12
We had one house with none of the general lighting/receptacles working at all. We opened up a whole bunch of them and they looked fine. But up on closer inspection I realized he had been pushing in all those #14 wires without stripping them. He thought it would somehow Pierce the insulation and make a connection.
That's not the fault of the backstab receptacle. Somebody didn't teach him right
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Rick 0920
Senior Member
- Location
- Jacksonville, FL
- Occupation
- Electrical Instructor
I haven't taken the time to research them as you have. But I still don't trust them simply based on what I have had to replace out in the field. I think it has to do with heat that is generated with higher currents. I'm sticking with my Ideal Twisters and I'll use the WAGO connectors on ballast changes.
Rick 0920
Senior Member
- Location
- Jacksonville, FL
- Occupation
- Electrical Instructor
Maybe so. I wasn't the installer. Only the guy called to remedy the problem. I can only imagine the problems that might happen if a multi-port WAGO were used on the grounded conductor of a multi-wire branch circuit. I guess I'm old school and stubborn, but I like to see those conductors with a good twist on them.
ptonsparky
Tom
- Occupation
- EC - retired
I short circuited the 24 volt secondary on a .5 KVA transformer. Brain malfunction. THHN Conductor insulation was melting. Lever Lock was fine. No fusing is needed for a shop workbench project. Right?
kwired
Electron manager
- Location
- NE Nebraska
- Occupation
- EC
Those are only as good as the care taken when installing them and I've seen many twist on connector failures over the years as well. Most being installer issues, some being environmental issues which would been potential problem with many connection methods.
ModbusMan
Senior Member
- Location
- Cleveland, OH
- Occupation
- Building Automation Engineer
What’s different about the grounded conductor on a MWBC?
- Location
- Illinois
- Occupation
- retired electrician
The damage to the loads on a MWBC when the neutral is open because of the resulting series parallel circuit which drops the most voltage across the loads with the higher resistance..typically letting the magic smoke out of the more expensive equipment on the circuit.What’s different about the grounded conductor on a MWBC?
But that makes the grounded conductor carry zero current. The comment I replied to inferred that the grounded conductor would be more likely to be a problem.
Edit - I see what you mean. If there is a failure of the grounded conductor connection, it wreaks havoc. I was thinking he meant that it was more likely to fail, which isn’t the case.