dead outlets

[mike4326]

I have a customer that called me and has 3 dead outlets.....they had plugged a sweeper into one and a minute later, no power...check breaker and breaker is fine, these outlet are all with-in 3 ft of each other. Kinda stumped , everything else work just fine in the room. Any ideas?

 

[Dennis Alwon]

I bet the outlet is back wired. Pull the outlets out and make sure the wires are connected. It is probably the outlet where they plugged the vac into.

 

[480sparky]

There's a chance the problem exists in a receptacle that works... it's just the load side connection there has come loose.

Another thing to check is continuity between the neutral and ground. If there isn't any, you've got an upstream GFCI tripped.

 

[roger]

I have a customer that called me and has 3 dead outlets.....they had plugged a sweeper into one and a minute later, no power...check breaker and breaker is fine, these outlet are all with-in 3 ft of each other. Kinda stumped , everything else work just fine in the room. Any ideas?

As the others mentioned, it's probably time to use your skills to remove the receptacles and check them.

Rover

 

[growler]

I have a customer that called me and has 3 dead outlets.....they had plugged a sweeper into one and a minute later, no power...check breaker and breaker is fine, these outlet are all with-in 3 ft of each other. Kinda stumped , everything else work just fine in the room. Any ideas?

You should always start out with the basics. Just because an outlet doesn't work doesn't mean it's dead. You should check to see if there is still power and just the neutral is open ( same symptoms ).

 

[jeff48356]

Exactly! I just got a service call yesterday evening for the exact same thing. I solved the problem by determining what all is on the circuit, and using logic to imagine how the original electrician may have routed all the wires. I first look at a box or device close to the panel (upstream), and go from there. I found the fault to be in a bedroom outlet where the wires were loose, and the connection finally built up enough resistance from heating to stop working. I solved it by making a pigtail with all 3 of each wire (black and white), and connecting the pigtails to a new receptacle, this way the continuity of the circuit doesn't depend on the receptacle. This happened to be the one that contains the home-run for the circuit (most upstream), so the entire circuit was inoperative until I made the repair.

 

[gar]

191204-2005 EST

mike4326:

This thread is getting old, and you have not reported back with what you may have done or found.

I would not approach searching for the point of the problem like the average electrician seems to suggest. Usually they want to start pulling stuff apart. Sometimes that may be necessary, but I would prefer that you make measurements. Then you do not disturb items that are not the problem.

We can assume that three wires (conductors) go to the outlets. These would be hot, grounded current carrying (call it neutral even though it may not be a neutral), and EGC. The highest probability is that only one conductor of these three is the problem. The lowest probability is that all three conductors are open circuits. Thus, my expectation is at least one conductor is conductive with a low voltage drop at a current level of 10 A.

For testing I suggest you have a 3 conductor extension cord starting at a known good outlet, and extending to your problem area, a 1500 W space heater, a high impedance DVM (10 megohms input) that resolves at least 1 mV, misc wires, and plugs, and possibly a Kill-A-Watt EZ.

To start use the extension cord EGC as your voltage reference point. With no load on the problem outlets measure the voltage on each each of the three wires relative to extension cord EGC, record the values. Next plug the heater into one of the outlets, and remeasure the said three voltages. These measurements should already tell you something.

Suppose all were not more than a millivolt or so. Would mean the hot is not hot, and there is a very high impedance in the hot wire, a really open circuit. Without the heater load if you are in the millivolt range to the outlet hot, then it has to be very open.

All the other combination of results you could obtain would direct you to the problem, if you understand electrical circuit theory.

Some experimental results on two outlets of a working circuit with the outlet spacing being 5 ft, and an assumed wire length of 7 ft of #12 copper.

#12 copper wire is nominally 0.001588 ohms per ft at 20 C. Thus, I can assume the resistance of my 7 ft wire is 0.0111 ohms. However, when loaded with 12.2 A the wire temperature will be somewhat greater than 20 C. Also there will be some differences in actual wire diameter. At 12.2 A and 0.0111 the calculated voltage drop is 0.135 V. The 7 ft is a guess, and I don't know the wire temperature. Measured results --- hot 0.151 V, and neutral 0.154 V. Close to the calculated value.

Suppose we found that loading the hot slot of one of your nonworking outlets with 12.2 A to the extension cord neutral produced a voltage from another hot slot to the extension cord EGC of the expected nominal 120 V, then at least to the two selected hot slots we can assume the hot circuit is probably OK. From voltage measurements to the various outlets you can determine which is the first in the series.

If the above looks good, then you test the neutral in the same way except now you use the extension cord hot as your power source.

If you do not understand this, then ask questions.

.

 

[MAC702]

Yes, but I could remove and inspect three receptacles in the time to get the extension cord out of the truck. And experience tells me there is a high likelihood of finding the problem visually once I do.

Much less looking for the other stuff and assembling it all before having to do math. And I like math as much as the next guy.

But yes, the OP should have given us the resolution by now.

 

[gar]

191207-1652 EST

MAC702:

It is most probable you will find the problem faster with your pull apart method, and possibly it is the best way.

However, pull apart will do two things --- work harden solid copper wires, and with backstab receptacles possibly create problems where there previously may have been none. I think it is most likely in mike4326's case the problem is backstabbing, and thus the first receptacle in the series.

Before pulling things apart I think more information would be useful. Which is the first receptacle in the series? What is the magnitude of the open circuit? Is hot or neutral a high resistance or both? Several simple measurements can be used to get this information.

The problem may exist in some location prior to the first receptacle. Although it is most probable to be at the first receptacle.

Feedback from mike would be useful.

.

 

[Knuckle Dragger]

I wonder if Mike ever resolved the issue?

 

[LarryFine]

I have been using the extension-cord-reference method for decades, but I prefer using a solenoid tester over a high-impedance volt-meter. The only time I use a meter is when I need to know the exact voltage. The solenoid is more "accurate" for testing.

Second method I use is to use an incandescent-equipped lamp, first plug in and confirmed on, then plug into a dead receptacle, and use a plug-in tester to wiggle other receptacles. If I'm alone, an extension cord lets me take the lamp into other rooms.

 

[Little Bill]

With the basic question from the OP and lack of response back, it smells an awful lot like either a DIY or handyman posted this.

 

[Knuckle Dragger]

I have a customer that called me and has 3 dead outlets.....they had plugged a sweeper into one and a minute later, no power...check breaker and breaker is fine, these outlet are all with-in 3 ft of each other. Kinda stumped , everything else work just fine in the room. Any ideas?

It's probably on a switch.
I will check for the simplest possible resolves first. Then start taking off plates and looking inside the boxes with out dismantling too much.

480 Sparky mentioned this as well: There's a chance the problem exists in a receptacle that works... it's just the load side connection there has come loose.

 

[LarryFine]

Agreed; when part of a circuit is out, the problem can either be in the last receptacle that works or the first one that doesn't.

Of course, the tricky part is deducing how the circuit was run, which is where experience and intuition come into the mix.

It's really fun troubleshooting older houses where the wiring was often run up and down between floors, not just horizontally.

 

[roger]

I think Mike is probably a DIYer and we should close this thread

Roger