An unusual 3 wire cable voltage

[Flatwall]

A 3 wire cable. Black, red, and white only. No ground. What does it mean when, black to white 0v, black to red 120v, red to white 120v? Thanks, Flatwall.

 

[Flatwall]

A 3 wire cable. Black, red, and white only. No ground. What does it mean when, black to white 0v, black to red 120v, red to white 120v? Thanks, Flatwall.

Im replying to myself with this answer. Red is Hot, White is Nuetral, black is ground. Does anyone agree. Thx, Flatwall

 

[davesparks]

That suggests that black and white are connected together and there is a 120V potential difference between them and the red.

Those readings alone don't confirm whether or not any of those wires are connected to ground.

 

[Megawatt]

A 3 wire cable. Black, red, and white only. No ground. What does it mean when, black to white 0v, black to red 120v, red to white 120v? Thanks, Flatwall.

I would have to say start at the panel and see how it is hooked up. It sounds like your wiring is hooked up wrong. If it’s truly hooked up right for 120 vac then you should have a neutral which is your white and either black or red for your hot and the other wire is probably the ground. These electricians that have worked on this should have taped to indicate for the purpose that they serve.

 

[Flatwall]

First thing is that the cable is 3 wire (red white and black) direct burial cable buried in pvc pipe as conduit, as an electrical source for a future greenhouse. It was wired to an existing outdoor receptical circuit, where it was connected I don't know. All I do know is which 20 Amp breaker protects the circuit. Hypothetically, if I assume that the white is the neutral, red is the hot, and the black is the ground. And I wire it as such to a 20 amp GFCI outlet and then test the outlet with a plug in GFCI outlet tester and the tester reads CORRECT. Is that a good indication that the cable is wired as I described? Thanks for any feedback. Flatwall

 

[Flatwall]

How can a wire be tested to see if it is a "true" ground?