Electrical question.

Farmhand

Super Member
My middle daughter mentioned that her iphone doesn't charge in a certain outlet in her room. She has a lamp plugged into it, and that works, but if she plugs her phone charger into that outlet, her phone doesn't charge.
Any ideas? I mean beyond the obvious, "Use a different outlet!"
 
I have the same issue with one outlet in my house so will wait for other helpful replies.
 
Sometimes the outlets are "split fed' where one half is always on and the other is controlled by a wall switch.
Maybe that's it!

Bob
 
Good suggestion, Spartanmanor. It's reading bang on 120 volts. However, it's an old 2 prong outlet- our house is 100-odd years old. I wonder if the contacts are worn to the point that the charger isn't making a good connection? I'll put in a new outlet this weekend and see what happens. Probably ought to do them all while i'm at it. My teenagers would appreciate having usb outlets in their rooms.
 
I bet it's an improperly grounded neutral and the charger can't get a good reference to ground. I'm kinda making that up, as I don't know enough to prove the theory. If I'm right, it's possible the neutral isn't bonded to ground at the panel?

Nevertheless - change the outlet, make sure it has a good ground and check polarity. That will fix your issue, I'd bet.
 
Good suggestion, Spartanmanor. It's reading bang on 120 volts. However, it's an old 2 prong outlet- our house is 100-odd years old. I wonder if the contacts are worn to the point that the charger isn't making a good connection? I'll put in a new outlet this weekend and see what happens. Probably ought to do them all while i'm at it. My teenagers would appreciate having usb outlets in their rooms.

Try to use extension cord plugged into that outlet, and plug charger into it. If it will work - its time to replace the outlet.
 
I bet it's an improperly grounded neutral and the charger can't get a good reference to ground. I'm kinda making that up, as I don't know enough to prove the theory. If I'm right, it's possible the neutral isn't bonded to ground at the panel?

Nevertheless - change the outlet, make sure it has a good ground and check polarity. That will fix your issue, I'd bet.

If the "neutral" connection was bad it's likely the light would be flakey too. Probably even more likely since the light draws more current, unless it's a LED bulb then probably similar current.

And, for the charger, the two or three I have are all non-polarized from what I recall off top of my head. So, while the receptacle certainly needs to be wired properly, that generally doesn't matter for this type of charger.
 
Last edited:
Good suggestion, Spartanmanor. It's reading bang on 120 volts. However, it's an old 2 prong outlet- our house is 100-odd years old. I wonder if the contacts are worn to the point that the charger isn't making a good connection? I'll put in a new outlet this weekend and see what happens. Probably ought to do them all while i'm at it. My teenagers would appreciate having usb outlets in their rooms.

Before you go off to buy new USB receptacles check the size of the wall boxes - primarily the depth. Older homes typically have fairly narrow and shallow boxes, just big enough for a standard receptacle and a bit of wire. The USB receptacles I've seen are a lot bigger than a standard receptacle.

I bought two USB receptacles to put in a couple key locations and they were too big to fit inside the existing wall boxes. Width wasn't the show stopper (although close), depth was the big road block. Ended up returning them since it would have been more work than it was worth (to me anyway) to make them fit.
 
Last edited:
Another possible consideration -

To use the phone charger in that receptacle, does it require the charging cord to be bent/twisted/pulled moreso than using a different outlet? If so, maybe the charger cord has a bad spot in it.
 
Sometimes the outlets are "split fed' where one half is always on and the other is controlled by a wall switch.
Maybe that's it!

Bob

Yeah, ran into that at a friends place. He did some rearranging and reversed the plugs (top to bottom) for a lamp and his TV. He couldn't figure out why the lamp worked but the TV didn't.

It didn't dawn on him right away to try the wall switch since the lamp that always had been controlled by the switch was already on. It was one of those "D'oh!" moments.
 
If the "neutral" connection was bad it's likely the light would be flakey too. Probably even more likely since the light draws more current, unless it's a LED bulb then probably similar current.

And, for the charger, the two or three I have are all non-polarized from what I recall off top of my head. So, while the receptacle certainly needs to be wired properly, that generally doesn't matter for this type of charger.

I thought of that with the light, but if the neutral were floating, the AC light wouldn't care - it would still light. But the floating neutral might be too much for the DC to maintain reference? As I mentioned, I'm just guessing - I'm out of my field here somewhat (I'm a building automation tech). But I do know that a floating neutral (or ground) can certainly mess with our DC control circuits. It's in our spec's, in our drawings and everyone is told - no floating transformers. In fact, we even tie our ground and neutral together at the control panels just to be sure.
 
I thought of that with the light, but if the neutral were floating, the AC light wouldn't care - it would still light. ...

The light and the phone charger are both AC-powered. If the light works properly then there is nothing wrong enough in the basic wiring of the circuit to preclude the charger from working. It's a more localized issue with the receptacle contacts, charger prongs, maybe the charger cable. Something like that.
 
The light and the phone charger are both AC-powered. If the light works properly then there is nothing wrong enough in the basic wiring of the circuit to preclude the charger from working. It's a more localized issue with the receptacle contacts, charger prongs, maybe the charger cable. Something like that.
I think that you are correct, Occam's Razor and all that.
But I had fun thinking about it, and so will stick to my exotic, enhanced version of the solution.
.
;
;
;
;
;
;
;
;
;

Oh, and when I said floating - I am referring to the primary (AC) side of the transformer. Messes with our DC signals, the zero mark isn't where it's supposed to be for the grounded devices that are fed that signal. And that's where my theory falls apart - the device being charged isn't grounded - it shouldn't care where the DC ref is at - right?
So, I'm betting you are correct. Still fun for me.
 
i would look at the construction of the plugs pins .. phone charger is maybe different to the lamp and not making contact .. or the sockets terminals are corroded and with the lamp drawing more current it breaks through the corrosion ..
 
I've delt with outlets that if the plug pins are not slightly spread out or in I would not get a connection. A new outlet should take care of it.
 
She's not by chance plugging her phone into the switched outlet just before she turns the lights off for the night and goes to bed, is she?
 
Back
Top Bottom