Electrical – Why is hot-ground reading a different voltage from neutral-ground

electricalwiring

I recently replaced a 20a simplex receptacle with a new 20a simplex Decora receptacle. I checked everything at the new 20a receptacle with a multimeter and here are the results:

Power on

  • Hot to neutral = 126.8
  • Hot to ground = 128.9
  • Ground to neutral = 4.764

Power off

  • Hot to neutral = 12.28
  • Hot to ground = 11.08
  • Ground to neutral = 5.535

Is this a phantom voltage or is this indicative as a loose neutral?

Other things:

  • receptacle is self grounding (brass clip on the "tongue," so I removed the insulators from the screws
  • receptacle is in a wiremold surface mount box
  • there is 14awg THNN running behind the 20a receptacle in raceway to an ungrounded receptacle
  • the ungrounded receptacle is on a circuit with four other receptacles and two ceiling fixtures (one pendant, one DC ceiling fan)
  • the aforementioned circuit (before the raceway connection) lacks a ground wire but I assume is grounded through conduit because I have verified conduit running behind the plaster with my own eyes (also every other outlet I've checked has an equal reading hot-ground and hot-neutral)

With both of the circuits off, the 20a receptacle reads:

  • Hot to neutral = 4.623
  • Hot to ground = 4.536
  • Ground to neutral = 0.107

The ungrounded outlet reads: 0.034

Best Answer

It's strange how these forums meant for getting answers to Qs so rarely just. get. a. direct. answer.

your question: "Is this a phantom voltage or is this indicative as a loose neutral?"

Answer: Most likely just a "phantom" voltage.

More info: There's a lot that could account for those few volts. Most consumer grade meters have some level of error, not much, but enough to contribute to reading a few volts. Most branch circuits deriving from a building power system in a condo complex will have a higher degree of "noise" for lack of [not really lack of, Just no point in getting technical or trying to "flex" as many do on these sites] a better word, moreso say than a single family home. Also branch circuits of long distance from their source of power have what is called voltage drop and this can develop a small usually harmless voltage between the neutral and ground.

TLDR: I would not worry about the readings you're getting at all.

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