High AC Magnetic EMF Emanation - House Wiring Puzzle

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Discussion Overview

The discussion revolves around the unusually high AC Magnetic EMF emanation from a specific outlet in a complex house wiring setup. Participants explore potential physical phenomena that could explain this anomaly, while also addressing the overall wiring configuration and its implications.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant notes that the wiring in the outlet box appears standard, yet the outlet exhibits high EMF levels, suggesting an unexplained phenomenon.
  • Another participant inquires about the function of red wires associated with smoke alarms and their potential impact on the EMF readings.
  • A participant observes that the EMF levels at the problem receptacle vary significantly depending on the status of the fan lights and the smoke alarm hot line, indicating a possible interaction between these components.
  • One suggestion is made to twist the insulated portions of the black and white wires in the problem receptacle to potentially mitigate the issue.
  • Concerns are raised about the overall wiring layout, with one participant expressing strong disapproval and suggesting that outlets and lighting should be on separate circuits for safety reasons.
  • Another participant emphasizes the dangers of the wiring errors and suggests consulting a professional electrician, while also noting that professional advice is not provided in the forum.

Areas of Agreement / Disagreement

Participants generally agree that there are significant issues with the wiring, but there is no consensus on the specific cause of the high EMF emanation or the best course of action to resolve it.

Contextual Notes

Participants express concerns about safety and wiring practices, but the discussion does not resolve the underlying technical questions regarding the EMF phenomenon.

Curiousphy
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Hi, please see attached image below. Do you know why the indicated outlet, out of everything in this mess of a circuit, has particularly high AC Magnetic EMF emanation? The wiring inside the outlet box looks normal and standard (2 neutrals on left, 2 hots on right, grounded correctly, no ground to neutral connection), I even replaced it with a different receptacle, same phenomenon. It's also not caused by external fields, because disconnecting the latter part of the circuit brings the field back down to normal.

What physical phenomenon could explain this? Thanks!

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What are the red wires at the smoke alarms and the red wire at the switch and outlet just below the alarms? And is the fan light always on?
 
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The red wires are the signal wires for the smoke alarms. The red wire at the switch below the alarms controls the split receptacle. When the fan lights are on, the field at the problem receptacle goes up to >4 mG. When they are off, the receptacle is at 0.9 mG. If the smoke alarm hot line is disconnected, it falls to 0.2 mG. I would have expected all receptacles prior to the alarms to exhibit the same characteristic, but no, it's just that one receptacle... but when you look inside the box, there's nothing special or wrong about it..
 
In that 'problem' receptacle, try twisting the insulated portion of the Black and White wires around each other.
 
Curiousphy said:
What physical phenomenon could explain this? Thanks!
A total abortion of a wiring layout, that's what ... OMG ... that would have electricians rolling over in their graves.
I have never seen something so bad ( and I'm not talking about the drawing).

#1 rule, you should not have power outlets on the same circuits as lighting
give them separate circuits and circuit breakers
and considering all your outlets are double sockets, I would strongly suggest that they be divided into at least 2 sections 2 x lots of 4 outlets each group with their own breakers

Get your wiring sorted out and THEN see if any of your other problems still exist

D
 
As others said, there are serious errors in this wiring. Errors that could injure or kill. This is definitely a case where a professional electrician is worth the cost.

But we do not give professional advice here on PF. Thread closed.
 
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