Originally Posted By: Don Kerwin
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I have been doing alot of research on the cause & effect of stray voltages, and here is a summary: If stray voltages exist within a home’s electrical system, then a portion of the current that should be returning through the neutral path is actually flowing through a different path - most likely via bonding /grounding connections back to the source - and due to some sort of insulation breakdown.
There are literally hundreds of regulations published by the NEC, NESC and OSHA to ensure a relatively consistent and substantial path from each electrical load back to the neutral connection on the utility?s meter. All involved with electrical work in residential and commercial installations are reminded over and over that the ground was never intended to be (nor should be wired as) a return path for neutral current.
So, why do residual (leakage) currents still exist? A simple answer is that the applicable codes were not followed, and that existing circuit connections were somehow overlooked or 'grandfathered? as newer codes were established.
That being said, wouldn't it be prudent to measure the total residual current (TRC) of a home to get an idea of the baseline TRC value? Then, monitor that quantity over a day, week and month to see if there are changes (loss of insulation) due to switching loads, weather, etc.?
A few other questions:
1) Does anyone know whether the utility is responsible for the level of TRC existing within a facility?
2) Has TRC ever been used as part of a pass/fail test during any electrical or building inspections?
3) Has any residential or commercial building owner ever used TRC as a tool for identifying faulty electrical or mechanical installations? (i.e. drywall screw or stud nail semi-piercing cable insulation).
4) Is there a maximum level of TRC which could be considered unsafe for residents or employees of a facility?
We have all recommended that prospective owners have homes tested for Radon, lead paint, termites, asbestos, UF insulation, etc. Should we add monitoring of TRC to this list of test to be performed before the signing of the final purchasing agreement?
Any feedback would be appreciated.