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Had another weird one today: 3 back rooms of a house (circa ’55) had wall theremostats typically used with elec baseboard heat but no baseboards. Hmmm. Radient ceiling panels? I see 1 a year or so.
Turn up the thermostats and pull out my tick tracer (GB Instruments, “Circuit Alert” GVD-504A Inductive Voltage Tester 50-600VAC) to see if I can find current in the ceiling. Yep. Turn off the thermostat, double check, and I realize my tick tracer starts beeping about 3 feet below the ceiling. Same thing in all three rooms???
What the heck could be going on? In most cases, this tick tracer has to be within 1/2″ or so of 110v to start beeping.
Bob
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There is an effect -- I can't remember its name -- discovered duing electo-magnetic testing in England several years ago when the low-level EM radiation health issue was geting more press.
Apparently under the roofs of building adjacent to power lines the EM radiation increases beyond the levels above the roof. Sory I can't be tighter on this but if you search EM radiation and health effects you will find the study on the web.
Also, the EM radiation of a single direction circuit with a hot wire only, such as running electical rads in series, will read differently than if the hot and cold wires are run parallel.
This should bring out the electricians and physicists
*House that age probably has radiant heating cable in the ceiling. Is the interior of the house plaster? If so then the cable is imbedded in the ceiling and its probably 220 volt.
*Look around outside the house. Are there high voltage power lines? A cell phone site? Ham radio? TV or radio transmitter? Any of these nearby could account for your results. Look around elsewhere both inside and out for the field you're detecting.-- J.S.
*Carl,Nope, drywall w/ skimcoat (not much plaster in these parts since WWII) but there are a few houses with radient panels. I can usually track the cable with mu tick tracer which typically only goes off within an inch or 2 of the cable, but not this time: in those 3 rooms only it would go off anywhere within those 3' of the ceiling (and only those rooms.)John, I didn't notice any of those things, but didn't particularly loof for them either. I'll look around if I get in that neighborhood again soon. Are you suggesting some sort of induction?Bob
*BobNot that unusual. I'll try to keep the physics lesson understandible and brief.When electrical current flows through a wire, a magnetic field is created. Hence EM, electro-magnetic. The shape of the magnetic field is cylindrical around the wire. {Those who studied this will remember the right hand rule.}Your tick tracer works by sensing faint magnetic fields. Many tracers also reject signals that are not near 60 Hertz to avoid false positive readings.Radiant panels typically have an array of many resistive wires run in parrallel across the panel face. Each of these wires creates a little cylindrical magnetic field. However, the net effect of all these fields creates one big magnetic field in the shape of, well, kind of oval or elongated circle {for the lack of better words}. And its pretty big.So, your ticker, which is sensitive enough to find a small current in an 1/16 diameter inch wire, is absolutely blown away by the large heating current in the panel array in the ceiling.And if it makes your ticker go off at three feet, I bet Ralph Nader would love to comment!JDahl
*JDahl,Thanks.<>Would he feel there's any health risk? Would anyone else?Bob
*BobThat's a Pandora's Box question. I have one Em meter that goes besirck near old tube type TV's and console stereos. The kind we sat 3 feet away from growing up. Yeah!Who knows, Bob. The scientisits will debate for ten years, coming to an inconclusive directive for all to follow, and then the politicians will cleanly follow up for another, say, 40...if we are lucky (or not). Anyway, my Grandma used to say:'We all die of something. I'll die of old age. But when you get old, poor boy, they'll have some name for it.'Live long Bob, and think not why.James [email protected]
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Had another weird one today: 3 back rooms of a house (circa '55) had wall theremostats typically used with elec baseboard heat but no baseboards. Hmmm. Radient ceiling panels? I see 1 a year or so.
Turn up the thermostats and pull out my tick tracer (GB Instruments, "Circuit Alert" GVD-504A Inductive Voltage Tester 50-600VAC) to see if I can find current in the ceiling. Yep. Turn off the thermostat, double check, and I realize my tick tracer starts beeping about 3 feet below the ceiling. Same thing in all three rooms???
What the heck could be going on? In most cases, this tick tracer has to be within 1/2" or so of 110v to start beeping.
Bob