Take the 2-minute tour ×
Home Improvement Stack Exchange is a question and answer site for contractors and serious DIYers. It's 100% free, no registration required.

I just bought a recently renovated house and the house inspector said that all the plugs in the basement worked.

Well... I plugged in several devices into the plugs and they don't power on. If I use my voltage tester I can see that the plugs are indeed 'hot', however they do not actually provide any juice.

All of the affected plugs are on the same breaker as well as the lights for the basement. The lights have no issues turning on.

What are some steps I can take to figure out what the problem is?

Update:
I opened up one of the plugs to see if there was anything visibly wrong. All of the contacts appeared to be wired correctly. I swapped out the receptacle for a new one I had purchased and I wired it into place. I attempted to plug a small test lamp into the new receptacle without fully screwing it into place and a bolt on the hot side that wasn't fully tightened brushed the side of the metal box thingy and caused a spark! eep! I'm guessing that means the power and the ground are working. I turned off the breaker and screwed the receptacle in properly and tried the lamp again and still nothing.

Update 2:
I purchased a receptacle tester and the receptacles all show blank, yellow, yellow which seems to indicate that they are wired correctly. Next step I will hook up a volt meter.
Receptacle Tester

Update 3:
Ok I plugged in the multimeter and it only goes to 30... to make sure my multimeter wasn't out of whack I plugged it into my working outlets and the needle went to 120V. Soo, for some reason I only have a quarter of the voltage I should have, weird.

Update 4: Resolution, so I caved and hired an electrician. It turns out the wiring for the plugs ran through a light fixure. Inside the light fixture all of the neutrals for the plugs were wired to each other, however, they were not wired to the main neutral! The electrician screwed a wire nut on the 2 bundles and low and behold, working plugs everywhere. Thanks for the help everyone!

share|improve this question
    
Do the receptacles work when the lights are on? The outlets could be wired in after the switch, so the switch has to be on to supply power. If that is not the case, pick up a Receptacle Tester and check that the receptacles are wired correctly. –  Tester101 Mar 12 '12 at 19:15
2  
What type of voltage tester are you using? Where are you measuring? –  Tester101 Mar 12 '12 at 19:16
2  
How can a plug be "hot" without "providing juice"? –  Jay Bazuzi Mar 12 '12 at 20:18
4  
A plug can have poor continuity with the house wiring, so it's energized as far as an NCVT or plug tester can tell, but won't support a real load. The plug contacts can also be broken or the neutral disconnected, so it looks energized to an NCVT but doesn't make contact with the plug's blades (a plug tester would correctly diagnose a problem like this). –  KeithS Mar 12 '12 at 23:19
add comment

3 Answers 3

up vote 11 down vote accepted

As I said in the comments to the OP and to Aaron's answer, there are several wiring failures that could cause an NCVT (non-contact voltage tester; usually a pen-looking thing that beeps when you point it at a live electrical wire) to light up, and some that even a plug tester can miss, but that would prevent a "real" load from being plugged in. The first thing to do is get a 3-lamp outlet tester (preferably with GFCI testing) to supplement your NCVT. The tester will correctly diagnose most of these things:

  • Open Hot: the black wire is present in the box but disconnected from the plug (or otherwise not making good contact). An NCVT can still light up if the wire is close to the faceplate. However, a plug tester will diagnose the issue. The fix is to flip this outlet's breaker, open up the plate and make sure all wires are firmly connected to the proper terminals on the outlet.
  • Open Neutral: the white wire is present but not properly connected to the outlet. Again, a NCVT will light up if the hot is properly connected (maybe even if it isn't), but a plug tester will properly diagnose the issue. The fix is the same as for an open hot.
  • Broken/Worn/Bent Outlet Contacts: The wires are hooked up correctly, but the outlet's contacts have poor or no continuity with the plug's blades. You may hear arcing (a rough crackle) as you plug in the tester or an electrical device. A tester MAY show correct wiring at a glance, but if you jiggle the tester the lights will blink off. Replacing the outlet is the solution here.
  • Neutral-Ground Swap and High-Resistance Ground: This would tend to affect an entire house's wiring, but it can be localized as well. What is happening is that the white and bare wires have been switched, and in addition, the ground (which normally ties back to the bus strip in the service panel and has full continuity with the neutral) has lost some continuity back to the service panel. There are several situations in which this can happen, most of them involving attaching grounds to house plumbing and then changing that plumbing along the way. An outlet tester may not diagnose this; the expected read is an "open ground" or "open neutral" (remember this would mainly be a problem if the neutral and ground are switched), but if there is some continuity then the tester may not show a problem.
  • Poor Continuity Of Hot Or Neutral With Outlet: One or more wires is making very poor contact with the outlet terminal. A plug tester may miss this; there is enough continuity for the tester (which only draws a few milliamps for its LEDs) but even a clock radio would have issues with the load induced by the poor continuity. The solution is to rewire the outlet securely, and if the wiring is sound on the plug then to check other wires in the box (with the breaker off of course). The next most likely culprit is the "bundle" of neutral leads that's normally in an "upstream" J-box; make sure all wires are wound tight and properly secured with a wire nut and electrical tape.
share|improve this answer
    
I don't think think there is anything better than a Wiggy or Knopp! The old solenoid testers. –  lqlarry Mar 13 '12 at 0:22
    
Wiggy & Knopp –  Tester101 Mar 13 '12 at 12:10
    
Any interest in submitting this answer for the blog? –  Steve Jackson Mar 13 '12 at 12:18
    
Awesome, I'll try this out and let you know my results. –  Biff MaGriff Mar 13 '12 at 14:49
add comment

A short answer if your voltage tester (non-contact beeper?) indicates "hotness" could be that the neutral return is open - it does not go back to the panel.

Turn off the breaker, open up a receptacle, unwire the hot and neutral sides from it, leave them bare, turn on the breaker, and take a multimeter and check the volts between the hot and neutral. If it is not 120 (assuming you are in a 120 location), but the non-contact tester indicates hotness, then most likely the neutral return is open.

share|improve this answer
    
Why would you unwire to test this? I would start with a multimeter just checking between hot/neutral, hot/ground, and neutral/ground without even taking the face plate off. If that works, whatever you're plugging in is probably broken. If not, check for obvious broken or bad connection, and THEN disconnect the receptacle to test. –  gregmac Mar 12 '12 at 21:50
    
True enough - I guess I just prefer to get the clutter out of the way and start with the simplest thing possible to find out what works. But you can certainly do some of the above testing without unwiring it, just if the wiring in the receptacle is all over the place, you might be chasing a dead end for a bit. –  Aaron Mar 12 '12 at 21:56
    
Ensure mutilmeter is set for AC and more than 120V then stick the probes in the outlet. (I always forget to set for AC and get zero volts.) –  dbracey Mar 12 '12 at 22:53
2  
The probable cause is good, so +1, but I would first grab a $5 outlet tester, plug it in and see if you get two amber lights. A plug tester will diagnose open hot, open neutral, etc that could be causing the problem. If the plug tester doesn't indicate a problem, then you can open up the receptacle and do further testing with a multimeter. –  KeithS Mar 12 '12 at 23:22
add comment

Sounds to me like your plugs could be connected to one of the light switches meaning that when you turn on a switch it will operate the plugged in appliances as well; some people do this when you do not have a decent light source in a certain area they can plug in a lamp and use the switch to turn it on/off or a radio or something of that nature. Test the light switch with something plugged in this may answer some of your issues.

share|improve this answer
1  
If you read update 4 by the OP, you'll see that the problem was a bad neutral connection. –  BMitch Mar 19 at 16:47
add comment

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.