Outlet with power won't supply power to anything plugged in

Question

Today we came back from church and our bedroom outlet did not supply power to the tv or cable box. Breakers were fine but reset. Power tester (stick like unit that sticks into the slot and buzzes) shows power on both leads of outlet. When breaker is off no power.

What could be causing anything plugged into it not to work? I'm guessing the tester is only testing HOT and not full circuit? (flow of electricity).

PS: Tried portable heater that works in another outlet and it too does not work, so it's not a failed cable box and TV from power surge or something.

Answer 1

You lost a neutral somewhere between that outlet and the panel.

The hot wire reads "hot" because you did not lose the hot; it really is hot.

The neutral reads "hot" because either there, or downline, there is at least one load plugged into the receptacle. This load connects the neutral to the hot, making the neutral hot too.

Follow the outlet chain back toward the main panel and find the first place it is dead (nearest to panel) and last place it still works (farthest from panel). Then disassemble and check both those places. The problem will be there.

The usual cause is a "back stab". Get rid of those.

This is not an emergency, because neutral is considered a conductor and is carefully insulated the same as a hot -- now you see why. On the other hand, if someone was bootlegging ground, this would be super bad news.

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"How can the load pull the neutral up to 120V? Normally it drops (reduces) the voltage from 120V to zero." That's true, the load limits current with a fairly high resistance However, the circuit is broken so zero current is flowing. What happens in that case? Ohm's Law tells the tale:

 E = I R 
 E (Voltage drop) = I (current in amps) x R (resistance in ohms)

Normally the load flows, say 2 amps across 120V, so E=120, I=2 and R =

 120 = 2 * R 

R is 60 of course, and that is a physical characteristic so it won't change. But with the broken circuit, current is zero, so look what happens to voltage drop:

  E = 0 * 60

That's right, E is 0, so the voltage drop between the load's hot and neutral will be zero. Since hot is 120V, so then must neutral.

Answer 2

1: You should really use a meter instead of those plug in devices - they do not tell you much.

A cheap analog meter might cost $5 and make sure it is analog - a gauge with a physical needle. I know the clerk at a store will tell you the goods on the digital but skip that the analog meter will measure correctly with no phantom voltages, the digital unless it has Lo-Z will not measure accurately.

Is it just this one outlet or all the outlets on that circuit breaker circuit ? If all outlets behave the same way - Replace the Circuit Breaker - it is defective. If only one outlet is defective read on.

Test Method 1: Using that meter you can measure for 120VAC between the hot and neutral connections and also test hot to ground. Anything less than 110 VAC means you have a problem with that circuit.

Test Method 2: Place an LED night light in the socket and see if it lights or even better a cell phone charger that has a little power light indicator to show that it is 'working' (don't plug the other end into your cell phone!) , if the charger indicator light is on or the LED night light is on - it does mean you have power there but does not tell you how much. Since you never said if one or all outlets on this circuit breaker circuit are affected, this test merely declares the possibility of a misbehaving breaker - Led charging light lit (lo current draw - probably a bad breaker).

If Test Method 1 Showed less than 110VAC or Test Method 2 the light on a cell phone charger lit up or even did not light - you have one of Five possible things going on.

1. A Bad Outlet.
2. A Bad Connection at the outlet.
3. A Bad Connection up stream from this outlet.
4. A Bad Connection in the Circuit Breaker Panel.
5. A Bad Circuit Breaker.

For items 4 and 5 I would check the other outlets controlled by that circuit breaker to see if they behave the same way. If they do 4 or 5 is your problem. If not 1 through 3 is your answer.

Answer 3

I had the same problem where the hot wire is hot on the whole circuit but nothing plugged in worked.

I am not very good with electrical but moving my breaker to a different slot in the panel fixed the problem.