I posted in another recent thread about the age of my system: house built in early 50s, appliance and kitchen wiring updated in the early 1990s. Home inspector was a former electrician and did a super job in my opinion. Don't really have any complaints or odd things happen, but have always worried about the age of the wires. IIRC He said because they had just switched to synthetic wire coverings, mine were OK. (they are not the kind in flexible conduit...they are the kind with a very finely braided covering that was probably white when new but is now a grayish-tan.)
Here's what's nagged me for years. All of the legacy lightning and plug circuits are 15 amp. Since I live alone this doesn't cause issues, generally. However, the legacy circuit for the dining room plugs - and i've seen the wires in the attic so I know it wasn't rewired as the kitchen and laundry room were - has a 20 amp breaker. Now, the wire is so old I wouldn't begin to be able to know the how to tell the slight difference between gauges. ALL of the old wire in the house looks the same to me. Presumably once upon a time there was heavier wire running to at least the electric stove, but that was all replaced w/modern wire.
Why would they have made the dining room receptacles 20 amp when everything else was 15 amp? (FWIW, there are separate lightning circuits for the DR and other main rooms of the house) Did 50s entertainment demand a lot of juice? Did Mom need to have her hot plates going in there, for buffets? LOL.
What I worry about is at some point an idiot just needed more juice for something and put a 20 amp breaker in there.

So...should I...
1) look for wire markings (never noticed any)
2) try to measure the wire somehow, see if the DR wire is thicker
3) just not worry about it because I seldom use the DR receptables other than vacuuming

Eventually when I have a vast surplus of moolah I plan to convert anything with the old wire to Arc Fault breakers, for ultimate piece of mind w/50+ year old wiring. I've been this close to buying a 20 amp arc fault just for that DR circuit about 5 times in the hardware store. Make a case for or against...

This post was edited by davidrt28 on Mon, May 19, 14 at 10:38