Crazy TV outlet

[djw2112]

This is driving me nuts. 

Hot to ground = 120V
Common to Hot = 55V
Common to Ground = 102V
Ground to Ground = 0V


I tested this with both a factory outlet and a normal household outlet hooked up to shore power.

But why is there 55V from common to hot, that should be 120V as well right?

I have a small fan pluged in but will not work, and the fan works in other outlets.

 

[Bjwinspect]

Sounds like something has partly shorted out at the back of the outlet.  I would pull the outlet out and check the readings on the receptacle

I am surprised this is not affecting other outlets on the same circuit 

 

[djw2112]

It is, there is one other outlet that has no power at all and its hard wired into the one with power.  No way two dif  new outlets are bad.  I even tested at the wire source and same.  I know my converter (and wether that means the inverter is bad too for the TV I don't know because i find no inverter so it has to be part of the converter) is bad but I am on shore power and so that should not matter.

Enough for today, tomorrow I am going to take the cover off the main power cord for the RV and see how it is hooked up to the RV inside the cover, maybe there is something in there that is not right.

I don't understand how its possible to have 120V from hot to ground but limited volts from common to hot.  This happened over 1 night, was working when I went to bed, woke up not working.

 

[Isaac-1]

What sort of meter are you using?

 

[coxid]

If your unit is under warranty take it back to your dealership ?Repair it NOW? If not under warranty it I would guess that there is a MINOR short at the first receptacle in the daisy chain. Open the breaker on that circuit remove the recepticals and check them out.

 

[SeilerBird]

It sounds to me like there is another load on the circuit that is causing the weird readings.

 

[djw2112]

If I do have a combo converter/inverter  would that mean that the sensor on that board that tells the system we have shore power could be bad as well.  I am hoping that when my new converter gets here, it will solve the problem.

Tested all breakers and all fuses, put the house outlet on another location and the outlet works fine but does not work behind the TV. 

I have a Extech Multiview 120 meter part number MV120, i found a user guide for it just now.

I set the meter on V 200 black lead in COM port and red lead on red port, the AC/DC button is in which is for AC and it shows AC on the screen.

looks like this

 

[catblaster]

  My guess is that what you are calling you common is a neutral that is interrupted somewhere in the circuit between an outlet and the breaker box, Like Tom said another device on that circuit is feeding current onto the neutral and you are picking it up with your meter. It could be as simple as a loose screw in the panel or an interruption in a feed thru box,possibly one of the stab lock connectors has broken the wire. Had this happen to one of mine along with the outlet being wired backwards.

 

[djw2112]

Ok thanks I will check that out tomorrow.  I almost wish something would give me a clue, like maybe alittle smell or something.  Tommorrow I will also pull the other factory outlet and look at that too. It is under a big window so maybe some moisture got in there somehow.

 

[John From Detroit]

Your "Ground to ground" is confusing.

Common I usually see as NEUTRAL

For the "Ground" to be half way between teh HOT and the Neutral is not uncommon at all. but we will come back to that.

What is a capacitor?  how is it made.
The answer is two electrical conductors seperated by an insulator

Example.. Two pennies (with wires soldered to them) glued to either side of a pane of glass.  (Some thign very similar to this is often used to demonstrate capicator construction in a classroom)(

Another example 2 wires layed side by side one (or both) insuilated.

Where have you seen something like this???? the black (hot) and bare (Ground) wire on a piece of ROMEX perhapes (Yup) ok.  now let's make a 2nd capacitor. equal in value (The WHITE (Neutral wire on the other side of the ground)  YOu got it.

When AC is applied.. Capacitors act a bit like resistors.. they pass current. since we have two IDENTICAL capacitors the voltage between center and either side is 1/2 the side to side voltage. or about 55 to 60 volts.

NOW: in a proper system .. The WHITE wire and the Bare Ground are BONDED way the blazes back at the service box below/behind the meter... (in the house) 

But you have an open ground .

 

[catblaster]

  Many years back when I was doing control wiring I learned to begin troubleshooting at the source....the breaker! Determine which circuit it is and everything that is on that circuit, then begin at the breaker box. Continue to the next outlet closest to the breaker and remove it to check the wiring.....continue on down the line, you may be surprised and have a "eureka moment".  It could be that just wiggling the wires while removing the outlet may temporarily fix it so leave the outlets removed until you have reached the end or found the problem.

 

[ChasA]

I think it's an open neutral (common)

 

[djw2112]

So an open neutral (common) just means that it is not connected correctly (partially connected)  if I understand you?

Yeah you may be right, today I thought I was seeing things because I plugged my little fan into the outlet to test it and at one point it began spinning, but never again.  I tried wiggling wires and tried to repeat what I had just done and nothing.  So yeah it may be something in the wall or behind something else that is not right. 

I really wish I could find a wireing plan for the outlet wiring in the RV or had one of those "see inside the wall" devices, because I have no clue where those wires go once they dissapear inside the wall.

The thing with this outlet is that since it seems to be fed from some kind of inverter as well, in order to totally kill it, i have to unplug shore power and flip the breakers and disconnect my battery.  Last time I got shocked with about 60+ V when I left my battery connected.

I guess this video might be a good first step, might save me from having to buy a converter if I find something wrong.

https://www.youtube.com/watch?v=gr2iNdMzqi4

Does that sound ok?

I also wish I could find a video that tells me what everything on the converter board does exactly.

 

[Bjwinspect]

I don?t think this has anything to do with your converter.    The receptacle and check wiring behind it.  Use care... you could be dealing with a hot wire where you would not expect it.

 

[djw2112]

Thanks, so it could actually be some bleed off from a inproperly connected wire or short (open neutral) somewhere in the line, rather than an inverter causing unexpected power.    I still think the first step is to start at the panel and work from there.  I may have to go buy one of those special beeping tools that you hook to one end of a wire and you can here it on the other end.  I am almost positive that these two outlets are totally seperate from everything else, I just need to figure out where they go behind the wall.

 

[Bobtop46]

Is this the front TV?  Front TVs often have a 12v connection to them that will disable the outlet (normally) when the engine is running.  This is part of the lock out to prevent you from watching TV while driving.  I agree something is wrong with the wiring for this outlet that needs to be found.  Either as the others above have mentioned above or from bleed over and shock from the 12v side.

This is how my manufacturer handled it (see photo) some handle it before the outlet, some inside the outlet.  Mine handled it after the outlet with the pictured device.  12v power comes in by the pink and white wire to the black box.  When the black box  senses 12v it cuts off the 120v to the plug.  I am supposed to plug this into the white outlet next to it and then plug my TV into the back of the black plug. I did not get a picture of the back of the plug.  It looks like a normal 3 prong outlet. 

When you got shocked which battery did you disconnect the house or engine?  or both?  if you only did one you may get shocked again.

If your TV cutoff (if equipped) is all wired inside or before the outlet you are getting stray voltage from a loose wire somewhere.  Other long shot is somewhere going to this outlet a 12v wire and a 120v have rubbed together (staple maybe.)  or find your hidden inverter if you have one.

 

[John From Detroit]

THe inverter is very likely the "Break" in the neutral.. SOME inverters have the option to Bond Neutral to Ground when in inverter mode. SOME do not (Smaller ones generally do not) some will "pass through the ground when in pass through (shore power) mode and I suspect some do not. Some it may not even have a wire hooked to NEUTRAL.

And as several of us have said. Open ground gives you half voltage on teh ground wire (55-60) exactly what you see. NOT MUCH Current.. (put any kind of load on it and the voltage imitates a rock in free fall. GOES DOWN) but a voltmeter is not much of a load..

Last time I got hooked up to a floating ground I pulled oh I'm guessing about 5-10 mA Felt it. irritating. not dangerous since it was confined to one arm).

 

[SeilerBird]

I really wish I could find a wireing plan for the outlet wiring in the RV or had one of those "see inside the wall" devices, because I have no clue where those wires go once they dissapear inside the wall.

You need one of these:

https://www.amazon.com/Non-Contact-Electrical-Detector-Inductive-Multi-meter/dp/B07BDHHSLZ/ref=sr_1_1_sspa?s=lamps-light&ie=UTF8&qid=1548686372&sr=1-1-spons&keywords=circuit+tester&psc=1

 

[Alfa38User]

The first thing you will need to determine is whether or not you are dealing with an inverter fed circuit or not. The make and model of your CONverter will be helpful here. If the only socket in question is for the TV/entertainment center, then you may be dealing with a small inverter skillfully hidden away but usually can be located. Did the TV work when not plugged in?? If so, you will be dealing with an inverter.

This brings to mind, what make and model of RV is it? The outlet for a TV in most motorized RV, where the TV is in view of the driver, will have wiring and circuitry to disable the TV while being driven (Federal  law). This brings up a whole new source of potential trouble spots when related to TV outlets.

 

[FunSteak]

I also lean to an open or loose neutral. 

When you're troubleshooting, as catblaster said it's good to start at the breaker and work up the line.  Don't just rely on stuff looking good - actually tug on the wires and make sure they are solidly connected (with power OFF, of course!)  If you see any receptacles wired via "back-stab" (wires stuck into holes on the back side of receptacle), I suggest removing them and reattaching to the screw terminals.  Backstabs are notorious for failing over time, and especially so in a giant, vibrating RV.

While you're in each box, use a light and check the box closely for any telltale scorch marks, too.  If anything looks even slightly wrong, replace it.