2 prong vs 3, what year?

[CheckItOut]

Most of the receptacles in the 1962 house I inspected today were not grounded. Only two wires going to the one recept that I pulled a cover off of. Certain rooms were had grounds but most did not. All rooms had 3 hole recepts - obviously not correct for the non-grounded rooms. What year were grounded recepts required?

[John Dirks Jr]

They started changing over in the early 60's. My house was built in 62 and was done as a grounded 3 prong system.

[Chad Fabry]

Late 60's in my neck of the woods.

[hausdok]

Hi,

Yeah, WJ, I caught myself writing that a few years ago and had to retrain myself to stop calling them the wrong term. Around here, it was about 1962 - 63. Sometimes homes from those few years will be confusing because some of our 60's homes still have K & T in the attics. You go through the entire house and find things grounded and then you get in the attic and discover the K & T and realize that all of the ceiling fixtures at the ceiling plane beneath the attic are ungrounded.

I've also run into homes from the 62 - 63 timeframe where there are two-slot receptacles on 2-conductor NM with separate equipment-grounding conductors that end on screws in the back of the metal receptacle boxes. With these, a wiggy confirms that the boxes are in fact grounded and one of those 3 to 2 adapters would actually work if the pigtail is secured to the cover screw as it's supposed to be. It's a little counter intuitive - finding a house with fully grounded receptacles a separate equipment-grounding conductor and 2-slot receptacles. When I see those, I've suspected that maybe the electrician was just getting rid of a bunch of the old 2-conductor NM and 2-slot receptacles.

This region seems to lag about 1 code cycle behind in most jurisdictions, so I think a reasonable range is about 1962 to 1964 to expect to still find 2-slot receptacles.

ONE TEAM - ONE FIGHT!!!

Mike

[randynavarro]

Originally posted by hausdok

It's a little counter intuitive - finding a house with fully grounded receptacles a separate equipment-grounding conductor and 2-slot receptacles. When I see those, I've suspected that maybe the electrician was just getting rid of a bunch of the old 2-conductor NM and 2-slot receptacles.

ONE TEAM - ONE FIGHT!!!

Mike

I wonder if it was because the metal boxes needed to be bonded back to the main panel--at least that's my theory.

[msteger]

I also use early 60s, but always noted it when I find ungrounded 3 wire type receptacles due to the potential safety issue. I recommend either changing these ungrounded ones back to 2 wire type, replacing with GFCI labeled no equipment ground, or have a licensed electrician rewire these receptacles.