Half-Baked Electric Outlet

[sleddriver]

First, Happy Thanksgiving to my fellow BITOG'ers.

I hope you're having more fun than I.....

I went to turn on a surround-sound pre-amp, quickly heard a "bzzzzt", then it failed to light. So I checked a power strip in the rear of the large entertainment center I built and saw it was dead. The internal breaker wasn't blown, so I looked further.

There is another power strip located behind the TV, and it too was dead. Yet both power amps & the active filter crossover, had power through a power switcher. All of the audio/video equipment is dead, save for these last three. Odd that......

As if that isn't odd enough, all equipment is fed from the same outlet! Yep, one duplex "port" is live. The other is dead. Go figure......

I also noticed the front porch lights, master bedroom lights, and several outlets were dead in both rooms. Problem is getting to this outlet is a major PITA as it entails disassembling a very large & heavy custom built entertainment center and moving over the even heavier base full of records, tapes, and accessories. Worse it's sunk deep into carpet.

Given that there is another outlet in the master, on the other side of the wall, I thought I could remove the box and go through that hole to pull the other box, rather than disassemble everything else. No joy.....turns out sparky put the faulty outlet on the opposite side of the stud! I didn't particularly want to cut the sheetrock.

I managed to move the base cabinet out a few inches by jacking up one end with two crowbars while a neighbor slid a piece of 1" Sch40 PVC pipe under it. This gave me a slick surface to slide on, though considerable effort was still required.

So, it's time to disassemble rather than eat.........







Per the other one I removed, this outlet is such cheap, junk that it doesn't even HAVE screw terminals! I didn't think that was possible! No screw terminals AT ALL??? No wonder the custom-builder-in-name-only chose this sparky due to his low bid. I'm surprised he even used 12ga. wire...and copper at that! Note he also pulled a hot runner off (red wire).

Needless to say but I'll be going back in with a spec-grade, reinforced nylon outlet WITH SCREW TERMINALS. I'll bet I can shatter the old one with one throw on a brick wall.....

Also see: https://bobistheoilguy.com/forums/ubbthr..._pi#Post4246913

 

[Al]

Yea and get a 20 amp one. No point skimping.

 

[mk378]

That looks like a split-wire system. The wiring in the walls is 12/3(*). The top (black wires) and bottom (red wires) of the outlets are fed from opposite phases in the breaker box. This allows the two circuits to share the neutral wire. You can also draw 20 amps from the top outlet, and another 20 from the bottom outlet. There should be a two-pole 20 amp breaker used. This guarantees the two feeds are on opposite phases (which is very important, otherwise the neutral wire will be overloaded), and also makes it safer that turning off the breaker will kill both sides of all the outlets.

You should go through the house and replace all those push-in outlets. Likely the problem is not at this outlet, but in one of the ones along the line from the breaker box to it.

When you replace the outlet you need to break off the tab that normally connects the hot side of the top and bottom outlets together. Leave the tab for the neutral side in place.

* Split-wiring fell out of favor when it was realized that it is cheaper to run two runs of 12/2 than one run of 12/3.

 

[CT8]

There must be a heavy load on the circuit.

 

[KJSmith]

Originally Posted By: CT8
There must be a heavy load on the circuit.


Heavy load or poor connection.
Wires have been getting pretty warm.

 

[mk378]

Push-in outlets make a poor connection automatically. This one does not look that completely burnt up. The break is probably somewhere earlier in the circuit.

 

[zzyzzx]

Originally Posted By: mk378
Push-in outlets make a poor connection automatically.


I agree. I really hate those puch in terminals and get rod of them and replace whenever possible with spec grade stuff.

 

[sleddriver]

Originally Posted By: mk378
That looks like a split-wire system. The wiring in the walls is 12/3(*). The top (black wires) and bottom (red wires) of the outlets are fed from opposite phases in the breaker box. This allows the two circuits to share the neutral wire. You can also draw 20 amps from the top outlet, and another 20 from the bottom outlet. There should be a two-pole 20 amp breaker used. This guarantees the two feeds are on opposite phases (which is very important, otherwise the neutral wire will be overloaded), and also makes it safer that turning off the breaker will kill both sides of all the outlets.

You should go through the house and replace all those push-in outlets. Likely the problem is not at this outlet, but in one of the ones along the line from the breaker box to it.

When you replace the outlet you need to break off the tab that normally connects the hot side of the top and bottom outlets together. Leave the tab for the neutral side in place.
Interesting....upon further examination, testing and having a look at the breaker box, it appears this outlet was wired as one receptacle always-HOT and the other (red) switched from a wall. The switched leg was the one that kept working, the other died. A good look at the removed duplex outlet revealed that indeed the HOT connecting tab was broken off. Good call there MK!

So now I have to trace the faulty hot leg backwards as it appears the problem lies upstream! My plug-in AC tone set won't work. However, I do have a low-voltage "fox & hound" that I've used. First, I'll need to turn off the Master Breaker to ensure the whole house is de-powered.

 

[sciphi]

Just about the lifespan of this old builder-grade stuff. It's why I'm going through my house and replacing all of it with new.

mk378, thanks for the reminder to check the connecting tabs. Several outlets in my house's bedrooms are wired like that, and I'd hate to make that mistake!

 

[eljefino]

Originally Posted By: Al
Yea and get a 20 amp one. No point skimping.


only if there's a 20 amp breaker, which OP *should* have.

There are also pro-grade 15 amp outlets that would be quite appropriate. If they're "winking" they're 20s.

 

[GatorJoe]

Originally Posted By: eljefino
Originally Posted By: Al
Yea and get a 20 amp one. No point skimping.


only if there's a 20 amp breaker, which OP *should* have.

There are also pro-grade 15 amp outlets that would be quite appropriate. If they're "winking" they're 20s.


Agree. Look for NEMA 5-20R receptacles.

 

[Donald]

Those speed wire connectors on the outlet are cheap and have little surfac contact area to allow the current to flow. Usually found in developments where they are in a rush.

The newer outlets have better connection methods that are quick and provide adequate current transfer.

 

[sleddriver]

temporarily surfacing for some air!

Shut down the confuser and cut off all power. Brkr #1 is labeled Mstr Bdrm. Had trouble with it resetting after manually exercising it a few times. Instead of latching, it would default to "limp". Exercised all and found two more that balked. One appeared nearly new. Might have replaced it years ago, but don't remember. Pulled the troubled ones out and discovered this:

Not sure how long she's and her friend have been hiding in there. No evidence of arching.

I rigged the low-volt fox-n-hound but the results were unsatisfactory. Wasn't able to detect any signal at any other outlets in either room, nor the BB. Very odd. Then I noticed a problem with my F77 DVM. It wasn't reading "infinity" on open. Switched to an old WaveTek.

Back at the "faulty" outlet, I discovered the 12/2 wht/blk wires are shorted (5.2 Ohms). Further, the resis. between the copper gnd wire & wht is OPEN. 12/2 wht to 12/3 wht is OPEN. Something's FUBAR.

How does a neutral & a hot suddenly become shorted? And remain so? Perhaps this short took out Brkr1.

I removed an X10 switch to the front porch lights as they lost power. I wanted to rule it out as the possible cause of the short. When I rechecked the wht/blk wires were still shorted. This explains why the fox-n-hound didn't work too well: the output was shorted. Most output-stages don't like that!

I need a new breaker. I also need to get up in the attic and trace Brkr1 wire from the box downstream.

Any other ideas?

 

[DBMaster]

Man, those house geckos get into everything, don't they?

 

[Al]

Originally Posted By: eljefino
Originally Posted By: Al
Yea and get a 20 amp one. No point skimping.


only if there's a 20 amp breaker,

Why?

 

[eljefino]

Originally Posted By: Al
Originally Posted By: eljefino
Originally Posted By: Al
Yea and get a 20 amp one. No point skimping.


only if there's a 20 amp breaker,

Why?


The presence of a 20 amp outlet implies 20 amps are available, so the whole system has to be up to snuff, so it can take one of these:

 

[JHZR2]

Originally Posted By: eljefino
Originally Posted By: Al
Yea and get a 20 amp one. No point skimping.


only if there's a 20 amp breaker, which OP *should* have.

There are also pro-grade 15 amp outlets that would be quite appropriate. If they're "winking" they're 20s.


+1.

 

[Al]

Originally Posted By: eljefino


The presence of a 20 amp outlet implies 20 amps are available,

"Implies" to whom? People look at an outlet and decide whether it can handle 20 amps?lol.
No one knows that. It is built to safely handle 20 amps so it is better able to handle 15 amps.
Your house..do as you please.

 

[tom slick]

A 20 amp receptacle is not inherently more heavy duty than a 15 amp, it just accepts a 20 amp plug. You have to buy a better "grade" such as "spec grade" or "hospital grade".

Back wire receptacles are 15 amp only and they only accept 14 awg wire, 12 awg doesn't fit.

 

[eljefino]

Originally Posted By: Al
Originally Posted By: eljefino


The presence of a 20 amp outlet implies 20 amps are available,

"Implies" to whom? People look at an outlet and decide whether it can handle 20 amps?lol.
No one knows that.


The people that designed 20 amp outlets know that.

You won't be "Unsafe" with 15 amp breakers and 12 ga wire, but you'll go nuts blowing breakers if you draw 20 amps.

Some copiers and welders have the funny winky plug I posted up. It's rare but out there and there are reasons.