Re: Change in NJ code laws
NEC 394.12(5) does not permit energized knob and tube wiring that is in contact with thermal insulation or soundproofing insulation. This could be an issue. The Consumer Product Safety Commission has made a statement that in this situation the overcurrent protection be reduced to
10 amps for #14 copper
15 amps for #12 copper
20 amps for #10 copper
The concern is that knob and tube wiring frequently has splices outside of boxes and that some splices are not as goog as new and generate extra heat. Also, the insulation usually too old to withstand 60 degree Celsius operation.
If you go over to Dr. Jesse Aronstein's web site
www.inspect-ny.com you will find out that there are some instances where thermal insulation has caused electricity to leak out of knob and tube wiring into the woodwork creating an extra cost on the electric bill. Some electrical utilites check for this and sometimes find somebody who 500 or 1,000 watts leaking into their woodwork.
Incidentally, Cleveland, Ohio and many of the surrounding suburbs had make work rules that said that you had to use knob and tube in houses long after a lot of other places had banned the stuff as unsafe. My girlfriend's 2nd bathroom has knob and tube wiring with PLASTIC insulation in the wires! This went on until NFPA amended National Electrical Code to ban the stuff nationwide starting with 1974 NEC. One of the suburbs around here was the last place in the U.S. to stop using knob and tube and they did not stop until the end of 1973.