Speaking as a plant E & I Technician who has studied (but not mastered, of course) the NEC for about 19 years, I have observed contractor-installed work that is mostly compliant and relatively safe, such as properly sized, but not properly supported raceways, 20-amp lighting circuits drawing 18 amps continuous (oops, forgot to acccount for the ballast?), cord-connected luminaires with excessive cord length and borderline work space clearance violations.
Then there are the more severe violations...
Motor starters installed without disconnects, and without properly sized heaters. Subpanels installed with grounds tied to neutral busses, standard fittings installed in hazardous locations, transformers not properly grounded and more serious work space clearance violations.
As a contractor, I would say that 75% of "added" electrical installations in houses over 20 years old are in violation to some degree from overfilled boxes to ungrounded 3-wire receptacles to unprotected feeder circuits.
Although difficult to do, I would estimate that less than half of what I see is compliant, with about 25% what I would consider serious safety problems.
[This message has been edited by Redsy (edited 11-13-2003).]
