Job Specs -- Gaussmeter - Ever Seen This?

[weressl]

I had to look up the word ?distal? in my dictionary; I thought it might have been a typographical error either in this post or in the specs. The word exists, and is defined as, ?situated away from the point of origin or attachment; terminal.? So they mean attach a device at the far end of each circuit, such that the circuit sees a 3 amp load.

Three things strike me as ?funny,? meaning that I am laughing at the engineer who approved that specification, but perhaps ?tragic? is a better word. First, they don?t require you to measure the magnetic field before turning on your 3 amp load, in an effort to establish the background field. But then, the background can vary from second to second anyway, so it would be hard to establish the amount of the field that is due to background, and not due to your load current. Secondly, they say what a particular value of magnetic field will indicate, but they don?t say that it would be a bad thing, and they don?t require you to take any corrective action to bring the value of field down to a lower value. The essential error in the spec is that they did not establish an acceptance criterion. You can measure a value of 0.6, and they say "so what"? The test is of no value if it does not give an acceptance criterion and establish requirements for corrective actions. Finally, I can conceive of no meaning to the phrase ?net current.? All current leaving the source will make its way back to the source. If it is not following the ?normal path,? meaning for example the hot and neutral wires, and instead finds its way back to the source via the conduit (owing to a fault internal to a receptacle or other device), then the ?net current? is still zero. I do not know what they are trying to prevent, or what bad thing they are trying to detect.

They did not say WHERE the measurement is to take place. Out in the yard? Next room. 1mm from the conductor?

Inductive load? Capacitive, combo?

The occupants will be walking around the house in tin-foil hats........

Sheeees...

 

[iwire]

Have fun with the 3-way switch's, they have a net current on the ''travelers''.

I don't see how that is possible using standard wiring methods. :-?

 

[paul]

Also in the specs, no MWBC, no fluorescent fixtures (tough with Title 24, possible), no petrochemical lubricants.

According to Riley

Recording Elevated Fields

But back to building wiring. As an EMF measurement consultant my job is to take magnetic field measurements at regular intervals throughout the building, record these measurements on a floor plan, and look for unusual field levels. The measurement unit used in the U. S. is milligauss (mG). The test instrument is called a gaussmeter. A correctly wired building that is not near a power line will usually show either 0.0 mG or a few tenths in most of the occupied areas of the building. The few tenths are usually due to fluorescent light ballasts, unless electronic ballasts have been installed, in which case you won't see anything on the meter. If there are wiring errors you will see milligauss measurements up to double digit readings in areas of rooms where the circuits run.

 

[zdog]

Back to the OP, I would leave this project to someone else, like some others have said, this will be a pain from the get go and you will probably never satisfy the requirements.

Roger

i agree. it doesnt seem like he even knows what the requirements are other than how to check.

 

[mdshunk]

"At the time of the final electrical closeout, and in the presence of the
general contractor, Architect or Owners, the electrician shall apply a
minimum load of 3 amps to the distal end of each electrical circuit. The
home shall be inspected under load using a gaussmeter. Any elevated
magnetic fields greater than .5 milligauss will indicate the presence of net
current."

Also in the specs, no MWBC, no fluorescent fixtures (tough with Title 24, possible), no petrochemical lubricants.

Other than the requirement to not use any MWBC's and not use fluorescent fixtures, they're really not requiring you to do anything special at all, other than conduct the test at the end. Payment does not seem to be tied to a certain clearance testing level, no do they spec that the wiring should perform to a certain level. That is sort of implied, but they certainly didn't write it that way if that's what they intended. If it was me, I'd do everything I normally would when wiring this place, with the exception of the fluorescent and MWBC matters, and call it a job well done. I would not go out of my way with special installation procedures in an effort to limit the gauss level, since the contract simply doesn't require that.

 

[acrwc10]

I don't see how that is possible using standard wiring methods. :-?

Well let's take into account "Leviton Acenti" multiple location dimmers, they use a single conductor to control the other locations. It may not seem like much but if you have a crazy home owner they are going to be looking for problems. People like this come up with bull sh-- along the way. I have seen enough of these types around here. They are full of CRAP they want to appear "green" no fluorescent lights, no fiberglass insulation, recycle all the wood, natural finishes on the house. Then they use wood from endangered rain forests for the floors and trim. Not to mention they have a "Hybrid" vehicle, and sold there gas hog to help pay for it, if they cared so much about the eenvironment they would have had the gas hog recycled not sold it.
EMF in a new house, if it is wired per NEC that won't be an issue, but the person that is asking about it is typically a hypochondriac,and there TV will always be tuned to psychic detective or haunting ghost shows or Silvia Brown '' apathetic psychic". BID HIGH !!!!!!!

 

[acrwc10]

You want the real inside scope on the people ask them how many cats they have if it is more then two , don't walk "RUN" :grin:

 

[DSamson]

Thanks All!

Thanks All!

Hello, OP here. You all are the best.

Thanks for the excerpt about the electronic ballasts not emitting EMF. That was helpful.

Thanks also for the links to the writer in this area and the gauss meter and measurement info.

Thanks also for the humor, just about had an accident when I read the tin-foil hats part. There were other good laughs too.

Yes, for those of you who noticed that the job spec. is inconsequential the way it is written, I noticed the same thing. I think the architect here lifted some language out of two books cited in the bid package. I think they liked the theory, but didn't know how to turn it into enforceable job specifications.

Thanks again.

 

[Dennis Alwon]

EMF in a new house, if it is wired per NEC that won't be an issue,

That is not exactly accurate. Read my earlier post. With NM cable and 3 ways you can wire the switches as I stated and still be code compliant but also create emf's. I have had a few service calls on these issues and have 2 of the 3 mentioned causes that created emf's in the house where I repaired the problems.

 

[tonyou812]

Hey Dennis were ya been man , I ve been wondering what happened to the "Voice of reason"?

 

[tom baker]

One of our moderators is the expert on EMFs, he wrote the book, that is Karl Riley. He developed a guass meter now sold by LSI?
In his book and video, he makes the statement that elevated levels of EMF are almost always due to common wiring errors by electricians. The EMFs should be measured after rough in. Then at final.
See if you can PM mr Riley. He is probably vacationing in a warm state.