Quote:
Originally Posted by DavGoodlin
The vermin-proof code amendment still makes sense and I bet that is an old requirement. When NM cable was first introduced in the late 1930's, it was tar-coated, tight-woven jacketed and paper wrapped the rubber-insulated copper conductors. A veritable feast for rodents  As NM cable evolved into the present thermo-plastic jacketed cable in the 1960s, the restriction remained because plastic cables are so easily damaged. I use a lot of MC cable (armor clad with separate insulated ground) in my own house, which is another 50 years older than Bob's. We get lots of mice, being surrounded by farm fields. My grandfather used BX (armor clad two-conductor) when he built their stone house in 1937. He wanted better than knob and tube, the universal method at that time.
Chicago, NYC and others are big enough that the "code" was amended to enhance safety due to population concentration. Unfortunately, few places with these risk factors could actually win against allowing the compromises inherent in "affordable housing". Philadelphia allows NM cable (aka romex) at least in low-rise buildings where the NEC permits it.  |
Milwaukee county didn't allow Romex wiring until the mid-70's. The electrical contractors claimed they couldn't wire the lower cost homes for the money allotted and still remain code-compliant.
Also, several surrounding counties didn't allow SE cable installations.
Some of the existing SE cable installations are starting to look pretty ratty 70 years later, especially after the tin-man worked his magic.