Troubleshooting a circuit

I am not an electrician but merely a homeowner attempting to diagnosis a circuit. Unsuccessfully so far I might add. This is a residence in rural Thailand and language with a local electrician is a major impediment. The voltage is 220V 50Hz AC, however, at the time of the testing, line voltage measured 208V. There is no code enforcement and I do not think there is even any code.

The circuit in question (Non-GFCI) is only partially visible but the problem seems to be isolated to this one circuit. Testing the receptacle (see drawing) with an inexpensive receptacle tester (Holub, Cat No. 19-060), all three indicator lights are energized at the same intensity. The troubleshooting key on the side of the receptacle tester does not cite this scenario. Testing the same receptacle with a multimeter provides the following results:

Line to Neutral = 208v

Line to Ground = 116v

Neutral to Ground = 88v

I am 80% confident the circuit was working properly but suddenly developed this problem without any intervention. I thought maybe the receptacle was coming apart internally but it checked out and the circuit measures the same with the receptacle removed. I have removed all the wire nuts and confirmed the wires are making good contact. Conduit is all plastic (PVC) with the exception of the junction box which is steel but it doesn’t appear any wires are making contact with the box.

Again, I am not an electrician and I do not understand what the voltage readings are telling me other than that something is wrong. Any advice would be greatly appreciated.

 

Line to neutral and line to ground should measure the same.
Neutral to ground should always measure 0v. You have an open or partial ground to that receptacle.

 

Thanks PJmax. I will start looking for an open ground