As you may have gathered, I'm quite interested in the development of wiring over the years, so I'm afraid I'm going to ask another "When did...." question.

From the various posts here and from several U.S. radio books I have, I understand that there are still quite a lot of homes fitted with non-grounded outlets.

From what date did the NEC require new wiring to use grounding receptacles?

well i would only be guessing, anyone have older NEC references here???

The oldest code book I have is 1978 & grounding type receptacles were required on 15 & 20 amp branch circuits (210-7(a)).

Seems to me that when I started my apprenticeship (73) everything was grounded but I had seen some fairly new houses that only had grounded outlets in the bathrooms & kitchens.

Maybe someone with a few older code books could narrow it down for us.

Sure wish someone would write a good "History of the NEC."

Tom

I have a U.S. book I picked up my travels dating from 1977 and that specifies grounding recepts. as an NEC requirement, so I knew it must have been earlier than that.

Didn't want to put a date into anyone's mind, but the reason I asked was I seem to recall seeing 1967 or 1968 in a book I read while over there. I wasn't sure if I was imagining it though, because our rules changed in 1967 to require grounds on lighting circuits.

Sounds as though that date could line up with you seeing fairly new houses in 1973 with ungrounded outlets in some rooms.


Often thought that a similar history of our IEE Regs. would be interesting. First editon came out in 1880 or 1890-something! Oldest edition I have is 1966, although I do have some reference to the previous edition in other books.

I once owned a house that was built in 1964 that had grounding type receptacles.

My parent's home had grounding recps. in only the kitchen, garage, laundry, & bath.
Built 1963 (are we getting closer?)