Moving into an old house, lack of 3 prong outlets

[kschachn]

Originally Posted By: westom
Please read what is written and not what you want to see. I never said anything about a ground wire.


Originally Posted By: westom
Electricians did not install a three prong receptacle because no safety ground wire existed.


Originally Posted By: westom
If a circuit had three conductors, then the receptacle was already a three prong type. It is a two prong receptacle because a code sufficient safety ground wire does not exist.


Originally Posted By: westom
Code is quite clear about this. A three prong receptacle can only exist if a third (safety ground) wire exists


You can see the confusion here.

 

[westom]

Originally Posted By: kschachn
And I've never seen armored cable with a separate ground wire. There's a grounding strip but no wire.
I have. The ground wire is not separate. It was inside the armor. Back then, the ground wire was only folded back to connect to the electric box - did not connect direct to a receptacle.

In some cases, an armored BX cable was sufficient to provide safety ground. In other cases - in a same building - it was not. So only two wire receptacles were used. Routine in the late 50's and early 60's were homes with both two prong and three prong receptacles. The electrician selected an appropriate receptacle according to how that circuit was installed. In some cases, armored cable could not provide a sufficient safety ground. Then a two prong receptacle was used.

Back then, a safety ground wire was not connected to a three prong receptacle. Its mounting screws were expected to provide a safety ground connection.

 

[westom]

Originally Posted By: kschachn
You can see the confusion here.
Yeph. Appreciate the correction.

 

[kschachn]

Originally Posted By: westom
Originally Posted By: kschachn
And I've never seen armored cable with a separate ground wire. There's a grounding strip but no wire.
I have. The ground wire is not separate. It was inside the armor. Back then, the ground wire was only folded back to connect to the electric box - did not connect direct to a receptacle.


Yes, the one with the separate grounding wire is MC or metal-clad cable. But that is a much newer type than would be in an old building like is being discussed here.

 

[Dan55]

The wire inside AC cable (BX) is a Bond, which permits the outside jacket to be used as a grounding means. Type AC cable also comes with a separate ground it is called Hospital Grade. Type MC cable has a separate ground wire inside and the outside jacket is not considered a ground (no bond).

 

[Cujet]

Originally Posted By: westom

Why would anyone install two porng receptacles when safety ground exists? They don't (DO THAT TODAY, BUT IT WAS COMMON IN YEARS PAST)



Fixed it for you.