Wiring Errors

Wiring Error Documents

Wiring Error Documents for Electricians, Building Biologists, and Clients Who Want to Do Their Own Testing

The following documents are for review by electricians who will be tracing and fixing any wiring errors that may exist in a client’s home, by building biology students and practitioners who are looking for wiring errors as part of their home or office EMF evaluations, and by clients who are able to do their own screening test with a Gauss meter for wiring errors.

An article specifically written for electricians on how to identify and repair wiring errors, as well as NEC citations related to them, can be downloaded by clicking here.

These handouts refer to material that we teach in the building biology advanced EMR 312 seminar on the testing and mitigation procedures for wiring errors in house branch circuitry. These cause magnetic field EMFs.

To see a three-page handout summarizing our procedure for screening for wiring errors during an EMF evaluation, click here.

To see a two-page handout with instructions on how to make a continuity tester for wiring errors on neutrals in a breaker panel as well as at any point along the branch circuitry in junction boxes, click here. We refer to it as the “blue box” because it is housed in a blue plastic box used by electricians as a junction box for a switch or outlet when non-metallic, or NM, Romex plastic circuits are used in walls. To purchase a ready-made “Blue Box Testing Kit”, click here.

To see a video in which Oram explains how wiring errors are created and how they cause magnetic fields, click here and scroll down to Part 5. The video is part of an eight-part series of lectures on EMFs, entitled “The Science of Building Biology”, presented by Oram and his colleagues at the Building Biology Institute. To see the other videos, click here.

To see both a one-page summary as well as a six-page full version of our wiring error mitigation procedures for electricians to follow to repair wiring errors, click on the following links. For the one page summary, click here. For the full version, click here.

Wiring errors are violations of National Electric Code Sections 250.6(a,b), 250.142 and 250-24 A5, and Sections 301-3(b) and 310-4:

  • 250.6: Objectionable Current Flowing Through The Grounding Path
(A) “Arrangement to Prevent Objectionable Current. To prevent a fire or electric shock, the grounding of electrical systems, circuit conductors, electrical equipment, and conductive metal parts must be done in a manner that objectionable current will not flow over the effective fault current path.”
  • 250-24 A5: “Neutral shall not be connected to ground at any point after the main service panel (containing the main disconnect switch).”
  • 301-3(b) (also known as 300-303(b)): “All conductors of the same circuit and, where used, the grounded conductor (neutral) and all equipment grounding conductors shall be contained within the same raceway, auxiliary gutter, cable tray, trench, cable, or cord.”
  • 310-4: “Conductors may not be paralleled, that is joined at both ends, so you can’t join two neutrals at a junction box because they are also joined at the circuit breaker panel where they terminate at the neutral bus.”

I recommend two clamp meters to assist in measuring net current on circuits. The Triplett 9200A Clamp Meter allows you to measure current on metal grounding paths, such as water pipes (up to 1 inch) and TV cables. You will also be able to measure individual conductors within circuits, such as the hot, neutral and ground wire, as well as measure for net current on the whole circuit. This small clamp meter allows you to get into tight spaces, such as inside junction boxes and breaker panels. Order the Triplett 9200A by clicking here.

For larger objects than the Triplett is able to wrap around, the FLIR CM55 Flexible 10″ Clamp Meter also allows you to measure current on metal grounding paths, such as water pipes, both large and small, and TV cables. To order the FLIR Clamp Meter, click here.

Much of this information is based upon the teachings of Karl Riley, author of “Tracing EMFs in Building Wiring and Grounding”. Karl was invited by Southern California Edison to record a 22 minute video explaining wiring errors to electricians. In the video, Karl is shown explaining wiring errors while an electrician stands behind him pointing to examples of the wiring errors Karl is talking about in a mockup board behind them. That book and DVD are available from LessEMF by clicking here. You can also see the same video on YouTube by clicking here.


  • “Suggested Protocol for School Electricians for Correcting Wiring Errors Causing Net Current Magnetic Fields”, by Karl Riley, available by clicking here
  • “What Electricians Should Know About EMF”, by Karl Riley, available by clicking here
  • “Should an Electrician Have a Gaussmeter?” by Karl Riley, on Mike Holt’s website, available by clicking here
  • Article “NEC Article 250 — Sections 250.6 through 250.12”, by Mike Holt on his website, available by clicking here
  • “Tracing EMFs in Building Wiring and Grounding” by Karl Riley. Book and DVD available from LessEMF by clicking here