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Posted By: Admin Back Plugged Receptacle Failure - 09/26/01 12:48 AM
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This pic was taken after I had merely removed the 6-32 screws and pulled the receptacle from the box. The "white" wires dislodged themselves, I did not remove them (and yes, they aren't very white anymore). To describe the picture in an effort to make up for the lack of resolution, the conductors were back-plugged #14 which had turned green due to corrosion and black due to heat on the bare copper, and with very charred insulation. This was the first receptacle in line that eventually fed a 15A Air Conditioner, with a very charred plug. The A/C was dropping the voltage down to 98V at the Receptacle that it used after the repair on the first one, so I will be replacing all receptacles in this mobile home. The switches aren't back-plugged, and seem to be in decent shape.

-Virgil


[This message has been edited by Webmaster (edited 09-25-2001).]
Posted By: sparky Re: Back Plugged Receptacle Failure - 09/26/01 10:57 AM
farily nasty,
however #14 is still ok per UL, the 'owner' of said MH should be glad this is not one of those self-contained devices, and let's not forget AFCI's are exempt for MH's ......
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Posted By: sparky66wv Re: Back Plugged Receptacle Failure - 09/26/01 11:58 AM
Here's the clincher:

After I had pulled the receptacle, I had asked the owner's permission to take the picture, and had explained the problem (which didn't take much convincing... the service call was "my outlet sparks when I push on the wall"). I also showed her the new receptacle with holes in the back, and I told her that ironically, it is still an accepted practice. Her response?

"Why?"

Why, indeed... (I was left speechless at that point)
Posted By: electure Re: Back Plugged Receptacle Failure - 09/26/01 12:15 PM
I once lived in a MH that had aluminum wiring. As the terminations went bad, the owner had replaced the recps....with stabbers. (He was even able to stab #10s!)
I was horrified to see evidence of smoke above each and every one of the recps that he had replaced. His comment was that they "Wouldn't sell them if they were no good." (never read the small print CU only)

He also drove a Ford Pinto.
Posted By: sparky Re: Back Plugged Receptacle Failure - 09/26/01 10:29 PM
LOL
with Firestone tires?
[Linked Image]
It'd be a different trade if this org. would poll us, or otherwise solict our input..... http://database.ul.com/cgi-bin/XYV/template/LISEXT/1FRAME/index.htm
Posted By: pauluk Re: Back Plugged Receptacle Failure - 09/26/01 11:22 PM
I understand from my reading that aluminum wiring was quite popular in homes for a while over there. Late 1960s/early 1970s ?

It never really caught on over here, not in smaller cables for residential anyway. Probably a good thing from what I've heard.

Quote
Originally posted by electure:
He also drove a Ford Pinto.

Isn't that the model that had the badly positioned gas tank that got hit in rear-end shunts?
Posted By: Bill Addiss Re: Back Plugged Receptacle Failure - 09/26/01 11:47 PM
Paul,

Yes, the Pinto was the car with the gas tank that would explode upon rear impact. I actually saw this happen up close. Bad scene. Instant fireball, no chance for anyone to get out.

Bill
Posted By: Scott35 Re: Back Plugged Receptacle Failure - 09/27/01 06:14 AM
Virgil,
You find some great photo opts!!! Keep up the good work!!!

You know, Bulls-Eye Barbecue sauce goes well with the Receptacle and Conductors shown in your photo!!! [joke]

Scott SET
Posted By: electure Re: Back Plugged Receptacle Failure - 09/27/01 10:21 PM
Virgil,
Do you suppose the AC at the end of line was the cause of these failures??
Posted By: golf junkie Re: Back Plugged Receptacle Failure - 09/28/01 02:04 AM
where are the posters who defended this practice in the thread we had a few months ago?

I hope this makes them reconsider.

GJ
Posted By: sparky66wv Re: Back Plugged Receptacle Failure - 09/28/01 03:25 AM
Scott W.,

Yes, the A/C at the end of the line definitely played a key role in the receptacle failure. When I replace the rest of them this weekend I'll have a better idea of where the damage is.

I wouldn't doubt that most of them will look as bad, especially kitchen and bath recepts (which, BTW, are fed via GFCI CB's).

GJ,
In one other poster's defense, he only used back-stabs for lightly loaded switches, which would be a little more acceptable. Ironically, the switches weren't back-stabbed in this MH, just the heavier loads...

[Linked Image]
Posted By: nesparky Re: Back Plugged Receptacle Failure - 09/30/01 03:24 AM
another reason to pigtail.
Posted By: Anonymous Re: Back Plugged Receptacle Failure - 09/30/01 05:39 AM
>another reason to pigtail.
Not really. Just a reason not to backstab.

The screw contacts are design to haul the full circuit current.

The springs in the back are designed to power clock radios.
Posted By: sparky66wv Re: Back Plugged Receptacle Failure - 09/30/01 07:29 AM
Dspark,

I guess if one pigtailed and backplugged (backstabbed) then the damage would remain in the receptacle with the heavy load rather than every one in line. I think that's what nesparky was getting at. But yes, I agree, anything more than a clock radio or such is too much amperage for back-stabbing over the long haul.

Also, You bring up an interesting question.

I've seen 15A GFCI Receptacles with markings indicating a rating for 20A "feed thru"...
Do regular 15A duplex recepts have the same 20A feed thru rating? I haven't seen it listed as plainly as the GFCI's.



[This message has been edited by sparky66wv (edited 09-30-2001).]
Posted By: Redsy Re: Back Plugged Receptacle Failure - 09/30/01 01:59 PM
Quote
Originally posted by Dspark:
>[b]another reason to pigtail.
Not really. Just a reason not to backstab.

The screw contacts are design to haul the full circuit current.

The springs in the back are designed to power clock radios.[/B]
Dspark,
Where did you get the information that the screw terminal are rated for the full circuit current, but the spring contacts are not? It would seem to me that if this is the case, the listing information would make it clear.
Posted By: Bill Addiss Re: Back Plugged Receptacle Failure - 09/30/01 10:42 PM
As a side note, I just noticed a full page ad on the back of a magazine for Wago brand push-in connectors that say they're good for a range of wire sizes in solid and stranded wire too!

Bill
Posted By: sparky66wv Re: Back Plugged Receptacle Failure - 10/01/01 12:35 AM
Stranded?!?! That's like trying to play pool with a rope for a cue stick!
Posted By: Bill Addiss Re: Back Plugged Receptacle Failure - 10/01/01 03:24 AM
This is an address to a page containing some technical info.

Technical Info
Posted By: sparky Re: Back Plugged Receptacle Failure - 10/02/01 10:57 AM
Stranded?!?! That's like trying to play pool with a rope for a cue stick!

rack em'up
[Linked Image] [Linked Image] [Linked Image]

[This message has been edited by sparky (edited 10-02-2001).]
Posted By: Redsy Re: Back Plugged Receptacle Failure - 10/02/01 11:32 AM
Quote
Originally posted by Bill Addiss:
As a side note, I just noticed a full page ad on the back of a magazine for Wago brand push-in connectors that say they're good for a range of wire sizes in solid and stranded wire too!

Bill

If you think about it, it seems stranded wire would provide better contact due to the flattening out of the wire, and therefore, increased surface area contact.
That being said, I still won't use them!
Posted By: electure Re: Back Plugged Receptacle Failure - 10/02/01 12:00 PM
I've tried to put a stranded #12 into a Wago, just to see how it works.
The result was that 1/2 the conductor went into the connector, the other half formed a "beard" outside the Wago.
Hardly a timesaver. Cut it off, throw it away, restrip, try again, twisting wire with lineman's first. 3/4 in, 1/4 beard.
They're junk.
Posted By: pauluk Re: Back Plugged Receptacle Failure - 10/02/01 04:55 PM
Quote
Originally posted by sparky66wv:
Stranded?!?! That's like trying to play pool with a rope for a cue stick!

Hehe.....

Maybe it's just that we've never used push-ins here, but I just don't like the idea of such a connection carrying 15A.

Clamp 'em tight!
Posted By: mickky Re: Back Plugged Receptacle Failure - 10/02/01 08:44 PM
Glad to see some hard evidence. My hunch was right; but then again, anything can be unsafe in the wrong hands...
Posted By: Anonymous Re: Back Plugged Receptacle Failure - 10/04/01 08:03 PM
>Where did you get the information that the screw terminal are rated for the full circuit current, but the spring contacts are not?
Empirical evidence.

>It would seem to me that if this is the case, the listing information would make it clear.
Nope. The listing info states 15 A maximum.
But that is apparently overstated by about a factor of 10.
Posted By: Theelectrikid Re: Back Plugged Receptacle Failure - 07/17/05 11:32 PM
Virgil! Have you been in my MH again!?! [Linked Image]
Posted By: Larry Fine Re: Back Plugged Receptacle Failure - 07/21/05 02:52 AM
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I've seen 15A GFCI Receptacles with markings indicating a rating for 20A "feed thru"...
Do regular 15A duplex recepts have the same 20A feed thru rating? I haven't seen it listed as plainly as the GFCI's.
It's hinted at in the exception that allows 15-amp receptacles on 20-amp circuits. 15- and 20-amp receptacles of a given type ("pro", residential, spec, etc.) are internally identical.

The slot shape is the difference; they're rated by the plugs they are designed to reject. Note that 125- and 250-volt 20-amp receptacles both accept 15-amp plugs.
Posted By: Texas_Ranger Re: Back Plugged Receptacle Failure - 07/22/05 06:32 PM
Regarding the Wagos mentioned above, the standard ones are _not_ rated for stranded wire! There are new-fangled ones with release buttons that are rated for stranded!

In Austria and Germany back-plugged receptacles (16A 250V rating, actual use 230V 16A) have more or less replaced any device with screws, Devices with open screws you have to bend the wire around actually havee been outlawed (at least in Germany) for a reason I don't remember.
The number of failures didn't increase damatically, so i assume the quality of the springs is simply better. :andy: (think it was him) once compared opened US and German backplugged sockets, and noticed the US one had brass springs that weakened over time whereas the German one had steel springs that hold up much better.
My opinion: I never had one fail and they are definitely very nice to wire. They're only a pain to get out again.
Posted By: :andy: Re: Back Plugged Receptacle Failure - 07/31/05 07:23 PM
hey ranger [Linked Image]

haven't been here for a while, and my favourite topic is hot again.
I believe the Screw/Pigtail system was discounted because it's not possible to make it protected of touching with your fingers. There are still some VERY cheap on-wall receptacles around in diy stores, that have screws and a square nut in an "U" shaped sheet, where you lay the wire in. They're junk, the sheet is too soft and widens when fixing the screw, the wire can jump out.

I have seen brass springs on connectors of very cheap 10A Light switches here, but not on Receptacles.

A very big & HiQ manufactor of receptacles, Busch&Jaeger, use spring contacts made by wago. Btw still not seen a molten wago yet [Linked Image]

I've bought a few receptacles on my US vacation in may, I tried to remove a wire with pushing the metal release lever down, the wire came out but the (brass?) lever stayed in the "pushed" position smirk.
Busch&Jaeger Parts have plastic Levers pushing the Spring to remove a wire, it works just fine.

Wagos for junction boxes are suitable for rigid-stranded conductors as it says on the box, but even I believe that's not a good way. Solid for regular push-wagos, nothing else. I use only the see-through ones, i don't know where the wire's at with the gray ones.

The new wago 222 series have levers for every connection and can grab stranded wires fine. But they're rather big.

[This message has been edited by :andy: (edited 07-31-2005).]
Posted By: SvenNYC Re: Back Plugged Receptacle Failure - 07/31/05 08:51 PM
Andy, I thought the preferred method for European devices like switches and sockets was the following.

Insert wire into a little hole. Tighten the grub-screw (set screw for americans).

The screw clamps against the bare end of the wire.

Obviously the screws are recessed deep enough (like on terminal strips -- the famous U-boats) so that you can't touch them with a finger.

I have a socket made by ABL-Sursum (a very reputable and quality manufacturer in my experience) that uses such an arrangement.

Receptacles and switches used in South Korea (and manufactured domestically) use the back-stab method, with the wire being clamped down by spring action from the terminal.
Posted By: renosteinke Re: Back Plugged Receptacle Failure - 07/31/05 09:56 PM
Here we go again.....

I have taken apart the "trash" receptacles, and I find that they don't have much of a grip on the wire, usually only two thin points of contact. Many times, I am able to pull the wires out- easily. I also note they are listed these days only to #14, and solid wire at that.

I have never used "WAGO" brand connectors, but I did just use about 800 of the Ideal "In-Sure" variety on a job recently. Looking into the case, it appears that there is a lot more metal contacting the wire. Of the 800, I found only one bad connection after assembly, and maybe discarded a dozen during assembly.

As for stranded wire....Ideal set up a 'demo' at the local parts house, and the stranded wire was more than stiff enough to enter the connector easily. In the field has been a different matter. Using #12 MTW, I had some difficulty getting the wire to enter the throat of the connectors; #14 entered without a problem.
I don't know what wire Ideal used in their display, but it entered the connectors a LOT easier than the wire I got from the parts house!


Tex, the arguments you ascribe to Germany (steady spring pressure, etc.) have all been made here in favor of the 'back stab' devices. They have not been born out by experience.
One thing I really like about your "choc block" strips is that each wire is held by a separate screw.....even wire nuts don't always grab all the wires. You can also add/remove wires without disturbing power to the other wires (what makes you think I ever work 'hot?" :-) )
Posted By: Texas_Ranger Re: Back Plugged Receptacle Failure - 08/01/05 02:31 PM
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Insert wire into a little hole. Tighten the grub-screw (set screw for americans).
Pretty uncommon for Austrian/German devices. Plugs and inline cord switches usually have set screw terminals.
There are two kinds of screw terminals that were used until the end of screw terminals. Either the compression plate variety where the wire is pushed into a hole and tightening the screw pulls a compression plate onto the wires or a stabdard screw with a big head where the wire is pushed under the head of the recessed screw, so it can't escape sideways. The latter method was very very common, the first was mostly used for the ground terminals.

Personally I've yet had to see a (European) backstabbed receptacle fail! With those I used (both cheapest Kopp and very reputable (and helluva expensive) Berker) It is close to impossible to pull out the wire without pushing the lever, you'll more likely break the wire.
Besides... you can't buy anything else here any more, so it's useless to complain! Apart from walmart-like Aldi/Hofer products no receptacles or switches have screw terminals or have had for years! 15 years ago most reputable manufacturers had already switched over to push-in terminals!

Regarding the choc blocks: you usually insert several wires (depending on the size) into one hole, so it's not as if each wire got it's individual screw! And adding or especially removing wires hot... yeah, it can be done, but removing wires will most likely cause at least some flickers to the other wires.
Posted By: SvenNYC Re: Back Plugged Receptacle Failure - 08/01/05 03:19 PM
Ragnar said:

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Apart from walmart-like Aldi/Hofer products no receptacles or switches have screw terminals or have had for years! 15 years ago most reputable manufacturers had already switched over to push-in terminals!


I guess then, these ABL brand sockets must be fairly old sockets. I bought them two years ago from an American supplier ( http://www.interpower.com ).

NIKO, the Belgian manufacturer, also sent me some surface-mount sockets as a sample about two years ago. They also use the little clamp method with the square washer under the screw.

I dunno what your experience with this brand is, but NIKO seems to be pretty good quality.

Are surface-mount sockets and switches still readily available in Germany & Austria? You know the kind used for the parallel wires stapled to the walls.

[This message has been edited by SvenNYC (edited 08-08-2005).]
Posted By: Texas_Ranger Re: Back Plugged Receptacle Failure - 08/05/05 05:19 PM
Yup, every hardware store still carries them, but hey are never used with flat cable, only with round NYM style cable or surface trunking. They're quite often used for additions to existing wiring where customers (or in many cases DIYers) don't want to open walls.
Posted By: Texas_Ranger Re: Back Plugged Receptacle Failure - 08/05/05 05:22 PM
Yesterday I _did_ have a backplugged receptacle blow up... but that was only partially the receptacle's fault. I had to install it hot, had already pushed all wires in but the phase wouldn't go in all the way, so I pushed the release button to get it out again. The instant I pushed the button there was a loud bang and flash just an inch from my finger, breaker, GFI and main fuse blew and the ground scraper was noticeably scorched. Yuck! Still haven't managed to figure out what actually happened.
Posted By: SvenNYC Re: Back Plugged Receptacle Failure - 08/08/05 08:44 PM
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Yup, every hardware store still carries them, but hey are never used with flat cable, only with round NYM style cable or surface trunking. They're quite often used for additions to existing wiring where customers (or in many cases DIYers) don't want to open walls.

What kind of terminal do they use? Screw or also the stab-in quick connect type?

If the surface mount devices used quick-connect terminals, that would most likely prevent them from being used by hobbyists for wiring up work-bench receptacles or even small temporary projects.

That would suck for people like me. [Linked Image]

I sometimes use ordinary lamp-cord for hooking up surface mount receptacles for use on my work-bench, for connecting small things like fans and soldering irons.

The ones sold here use screw terminals, which lets you use either solid or stranded (like lamp-wire) conductors.

[This message has been edited by SvenNYC (edited 08-08-2005).]
Posted By: Texas_Ranger Re: Back Plugged Receptacle Failure - 08/11/05 08:33 PM
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What kind of terminal do they use? Screw or also the stab-in quick connect type?
The very common Kopp brand surprisingly still have screw terminals, even quite nice ones. Recently I installed a flush mount three way receptacle that fits a single gang box (brand new from the store) and it had screw terminals. The way the terminals were built indicated you could just insert a straight wire and tighten the screw, upon trying that the wire escaped from under the screw head. So I pulled the wire back out again, bent it around the screw and everything worked fine.

Last week I tried using one of the Hofer screw terminal receptacles... and immediately sent the entire pack to the trash! Very thin brass everywhere, the plastic so soft the compression plates would spin freely when the screw was tightened... no way that could result in a safe and solid connection! So an 8 pack of never used receptacles ended up in the trash can... and if I _ever_ find the other pack we bought a year ago it's going to go the same way, i swear!!!
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