dsen31
 
Reply Mon 15 Jul, 2013 08:09 am
So I just purchased a property and I am having issues with the kitchen light, it doesn't turn on, and I am going to try my best to describe the problem. One of my coworkers came over and he pulled out a wire tester to see if there was power running to where you screw the bulb in. Sure enough, there is power to it and all the wires are live. Then we tested each of the two switches and there is power there as well, and for some reason the lights won't turn on (and yes I changed the bulb to a new one). The weird thing is is that there is still power running to it, even when the switch is turned off. I am hoping with my description someone can offer some insight. I need this to work!
  • Topic Stats
  • Top Replies
  • Link to this Topic
Type: Question • Score: 6 • Views: 3,103 • Replies: 22
No top replies

 
BillRM
 
  1  
Reply Mon 15 Jul, 2013 08:16 am
@dsen31,
Let see the switch could be bad and the reading of voltage at the socket is cause by the switch having a little leakage of current through it at all times.

A meter will draw a mill amp or less of current so that might be why you are getting a voltage reading at the socket but the leakage is not in the many amps range needed to light a bulb.

Carefully try shorting around the switch and see if a bulb will light.
0 Replies
 
Ragman
 
  1  
Reply Mon 15 Jul, 2013 08:17 am
@dsen31,
Is it a fluorescent or incandescent fixture?
dsen31
 
  1  
Reply Mon 15 Jul, 2013 08:19 am
@Ragman,
Incandescent
Ragman
 
  1  
Reply Mon 15 Jul, 2013 08:22 am
@dsen31,
Having a technical background (computers) I can only take a guess. I'll offer a guess and say the socket has some connectivity (corrosion or an open when the bulb is screwed in) problem. Why not hire an electrician?
dsen31
 
  1  
Reply Mon 15 Jul, 2013 08:30 am
@Ragman,
It may come to that. After buying the house I'm strapped for cash.
BillRM
 
  1  
Reply Mon 15 Jul, 2013 08:53 am
@dsen31,
As I said there is a good chance the switch is bad and shorting around the switch or replacing the switch for a few dollars would be my first troubleshooting step.

PS I am not an electrician either, however I do have an electronic engineering degree
0 Replies
 
BillRM
 
  1  
Reply Mon 15 Jul, 2013 08:55 am
@Ragman,
Quote:
socket has some connectivity (corrosion or an open when the bulb is screwed in) problem


Take note he is seeing voltage on the sockets at all times so once more that sound like a bad switch to me that is allowing a small current to flow at all times.
0 Replies
 
dalehileman
 
  1  
Reply Mon 15 Jul, 2013 10:07 am
@dsen31,
31, Bill is quite right. Another possibility is capacitive coupling: One of the two wires, probably neutral, is broken but at some distance from the outlet so that there's enough capacitive coupling between it and ground to yield a substantial reading on a voltmeter, esp one of "vacuum-tube" or "emitter-follower" circuitry not imposing a substantial load
BillRM
 
  1  
Reply Mon 15 Jul, 2013 10:44 am
@dalehileman,
Quote:
"vacuum-tube"


Lord you are dating your self over the used of the term vacuum tube as it been thirty or even forty years since I had my hands on a vacuum tube volt meter--------- Drunk Drunk

However you are right that a high input meter such as a meter with a FET input stage would show such coupling.

I will however stand with my suggestion of looking at the switch as a first stage in troubleshooting the problem.

PS I can still remember receiving for a birthday present on my 12 or 13 birthday a wonderful vacuum tube VOM from my parents.


BillRM
 
  1  
Reply Mon 15 Jul, 2013 10:58 am
Quote:
When I took my amateur radio operators license in 1964 the tech questions were on tube theory.


When I took my FCC first class license exam in the early 1980s there was a lot of tube theory still on it.

I wonder if the FCC have updated their tests to this day!!!!!!!!!

Remember high freq "light house tubes" for example as that was one of the questions on the test I still can recall.
Ragman
 
  2  
Reply Mon 15 Jul, 2013 11:07 am
Re the questions posted by OP, feel free to ignore my commentary. Others are more informed.

As long as we're letting our blue hair down, is this the meeting of tube-tapper's anonymous?

I recall bringing iffy tubes over to Ligetts/Rexall drug store and testing tubes on their free tube tester ... oh..somewhere around 1964 (I was newborn, of course). When I took my amateur radio operators license in 1964 the tech questions were on tube theory.
BillRM
 
  1  
Reply Mon 15 Jul, 2013 11:14 am
@Ragman,
I wonder how the postings had gotten out of order on this thread that is a first time I saw that happening.

Maybe a tube had gotten weak in one of Robert servers........ Laughing
0 Replies
 
mesquite
 
  2  
Reply Mon 15 Jul, 2013 11:55 am
@dsen31,
Since you mentioned two switches, I assume your light is a two way light. Here is a diagram of a two way setup.
http://3.bp.blogspot.com/-u6laJ6xF_RU/Th2FYfChY0I/AAAAAAAAAE0/uKLZy4DRf0o/s640/TWO+WAY+WIRING.bmp
As Dale and Bill had mentioned, there are many reasons for you to get a false indication of power to the lamp at all times. Without knowing what was used as a "wire tester" and the skill of the operator, it is hard to comment on.

One other reason to get an indication of power all the time is that the line (hot) wire could be connected to the light and the switching done on the neutral side. I have seen this in some older houses.

Since the most common cause of the problem is a switch, I would test them first with an ohmmeter being sure to kill the power to the circuit first. Check that each switch is capable of opening (high resistance) and closing (less than 1 ohm) the connection between the common to A and common to B terminals of the switch.

One other possibility if the light has never worked since you got the property... the previous owner may have tried to replace a switch and wired it incorrectly. Use the above diagram to see how it should be wired.
engineer
 
  1  
Reply Mon 15 Jul, 2013 11:58 am
@dsen31,
I'm really surprised by your problem. You have 120vac at the fixture of an incandescent light but you can't get it to work? If it was a fluorescent fixture, I'd blame the starter on the fixture but an incandescent fixture is the simplest circuit imaginable. My suggesting is to buy a light socket adapter for $3. (You could probably return it when you are done.) Plug it in and check the voltage again at the outlet. If you still have power, plug something into the outlet and try to draw a load. If that works, sell the house, it is haunted. If it doesn't draw current even though you have a voltage signal, you might have a short to ground somewhere on the downstream side of the wall switches. Use your voltmeter to check the resistance on the downstream of the wall switch with no light bulb installed.
0 Replies
 
DrewDad
 
  1  
Reply Mon 15 Jul, 2013 12:03 pm
@dsen31,
I suspect you're not getting good electrical contact when you screw the bulb in.

Either the contacts are corroded, or something is preventing the bulb from being screwed all the way in.

And did you test your new bulb in a known-good socket both before and after trying the non-working socket?


Edit: Oooooops. I see Ragman beat me this.
0 Replies
 
dsen31
 
  1  
Reply Mon 15 Jul, 2013 12:06 pm
@mesquite,
Wow this was a massive help. Thank you! When I looked at the building, the light worked, and it was working for a bit when I was moved in, and now its not.
0 Replies
 
dalehileman
 
  1  
Reply Mon 15 Jul, 2013 12:39 pm
@BillRM,
http://able2know.org/topic/218182-1

Quote:
"vacuum-tube"


Quote:
Lord you are dating your self …..
At 82 it feels like day before yesterday

Quote:
……. such as a meter with a FET input stage would show such coupling.
Indeed Bill you're a step ahead of me there, where I was thinking of emitter follower…….

Quote:
I will however stand with my suggestion of looking at the switch……...
The breaker too. I've been flummoxed by the one appearing to be ON when it really isn't

Quote:
….. on my 12 or 13 birthday a wonderful vacuum tube VOM from my parents.
Ah the good old days when we had to plug it in. But remember that huge meter…..
0 Replies
 
dalehileman
 
  1  
Reply Mon 15 Jul, 2013 12:48 pm
@BillRM,
Quote:
Quote:
….. 1964 the tech questions were on tube theory…...1980s there was a lot of …...
As I remember I won mine in 1945 give or take a year or so

http://applevalley-review.com/node/777

Quote:
I wonder if the FCC have updated their tests to this day!!!!!!!!!
Might make interesting sub for new thread

Quote:
Remember high freq "light house tubes" for example…...
Ah yes I do remember, it was a funny looking affair
0 Replies
 
Placid Carcass
 
  1  
Reply Tue 16 Jul, 2013 01:58 pm
A good start as mentioned is to check the neautral connections to make sure they are done correctly. It seems to be the most likely problem considering you have power at the socket.

If you indeed to have a 3-way setup for the light, i would also make sure it wired correctly as that would explain why you have power at the socket at all times.

So to sum up, check neutral connections and 3-way switch connection if present.
 

Related Topics

Main Breaker Tripped 2x - Question by decadent
240 Why - Question by lenchase
Electrical Wiring Question - Question by cdime
electrical showers - Question by grains93
6000W cooktop circuit - Question by 1hairycanary
Tempory power supply - Question by 51 nelson
 
  1. Forums
  2. » Electrical issue
Copyright © 2020 MadLab, LLC :: Terms of Service :: Privacy Policy :: Page generated in 0.03 seconds on 08/06/2020 at 06:46:39