From Today's Inspection

[Richard Stanley CMI]

National Electric Code 110.12 Internal parts of electrical equipment, including bus bars, wiring terminals, insulators and other surfaces, shall not be damaged or contaminated by foreign materials such as paint, plaster, cleaners or abrasives, and corrosive residues. There shall not be any damaged parts that might adversely affect safe operation or mechanical strength of the equipment such as parts that are broken; bent; cut; deteriorated by corrosion, chemical action, or overheating. Foreign debris shall be removed from equipment.

[Jeffrey R. Pope]

Originally Posted by Robert Meier

I'm curious, what do you guys do with the results you get from voltage drop testing?

Simply provide the information. When it's excessive (10% or higher at multiple locations), I will recommend evaluation.

[Robert Meier]

Originally Posted by jpope

Simply provide the information. When it's excessive (10% or higher at multiple locations), I will recommend evaluation.

So with a VD that high are you looking for a poor connection or is 10% just a standard that inspectors use? The NEC is silent on the issue (unless you're installing a fire pump) so I was just wondering how you apply this information.

[Jeffrey R. Pope]

That's my own "guideline" and it fluctuates. Most inspectors don't measure voltage drop. I use voltage drop measurements as an indicator for many things, but a "poor connection" is certainly a consideration.

As I'm sure you know, excessive VD indicates high resistance within the circuit. This resistance can be caused by a number of things, so it really depends on what I'm looking at, and/or what I'm looking for.

For instance, in a home with AL branch circuit wiring, measuring VD can help to determine the integrity of the connections at the pigtails and/or receptacles. I use my findings to help determine my written recommendations.

The NEC recognizes voltage drop as an "efficiency issue," but makes no comment as to the cause (other than conductor length) or effects.

[ROBERT V. YOUNG]

Good tool to buy Mr.Pope ?

[Jeffrey R. Pope]

The SureTest is a "must have" for any inspector as far as I am concerned. The extent to which you utilize it is up to you. Many will argue that incorporating the results VD goes well beyond the scope of our profession, which is true to a degree.

My position is different, however. I prefer to have as much reliable information as possible in order to validate my findings. I make my recommendations/assessments based on an accumulation of available information.