Hello Doug, You are correct in that ungrounded outlets (NEMA 1-15) are sold to replace older ungrounded outlets. NFPA 70, the National Electrical Code (NEC), does not allow you to replace an ungrounded outlet with a three-pin outlet (NEMA 5-15) if the ground is not connected. There are millions of older homes and businesses without ground wires running to each outlet. The ungrounded outlets are sold to replace existing damaged or otherwise faulty outlets of the same type.
However, there is a better option in older buildings. You can replace ungrounded outlets with GFCI outlets. GFCI outlets will come with instructions on how to do this. The ungrounded outlets protected by the GFCI must be marked “NO EQUIPMENT GROUND GFCI PROTECTED”. You will typically find stickers with this notice in the box with GFCI outlets. (See the third bullet under “Receptacle” at the following link.) https://www.cpsc.gov/PageFiles/118853/099.pdf The specific code reference is NFPA 70:2014 section 406.4 (D)(2). It specifies how ungrounded receptacles are to be replaced by either replacement ungrounded receptacles or GFCI receptacles. The GFCI doesn’t need a ground connected. It will still trip if there is an unbalance in the current between line and neutral even without a ground. Installing GFCI protection in older circuits with ungrounded outlets provides a reasonable level of protection and is far better than leaving the ungrounded outlets as they were originally installed. The NFPA hasn’t written ungrounded outlets out of the code for practical reasons. These outlets were still commonly used even through the 1960s and the wiring methods and materials used are typically such that they would not necessarily have degraded to the point where they are unsafe. Requiring replacement of ungrounded systems with grounded systems would be expensive and would likely deter homeowners from making any safety improvement. The GFCI option provides a quick and inexpensive option that provides a reasonable level of protection. That being said, there were some wiring products that did not meet the test of time and should be addressed. These include aluminum wiring and certain circuit breaker and panel types. Knob and tube wiring was last common nearly a century ago. The materials do not age well and the systems typically do not have the ampacity necessary for modern appliances. The risks are greater for knob and tube wiring and the general recommendation is to replace it with a modern system. Best regards, Ted Eckert Microsoft Corporation The opinions expressed are my own and do not necessarily reflect those of my employer. I am not a licensed electrical inspector or home inspector and the information I have provided are ony my opinions. Please consult a professional when evaluating the safety of electrical installations in your home or place of buisness. From: Doug Powell [mailto:doug...@gmail.com] Sent: Sunday, January 1, 2017 8:39 AM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: [PSES] Non-grounded electrical outlets This is a question for the North American crowd. The other day I purchased an electrical outlet for residential use to replace a worn out device. What I didn't realize is the part in the store bin was the ungrounded type. At least I didn't realize it until I tried to install the outlet and was unable to find a connection point for the ground wire. Another trip to the hardware store... For me, this raises a question, what is an ungrounded outlet doing in a retail store in the first place? The only thing that I can imagine is the national electric code allows legacy installations from years ago (1950s?) to be maintained and repaired, or "grandfathered in" when the repair or update is very minor. It also seems that putting a three prong outlet with an unterminated ground connection may put an end user at greater risk. So ungrounded replacement parts are made available. If this is the case, I also find it interesting that parts for the old knob and tube method of wiring are not available too. Or possibly they are available somewhere and this is just a case of supply and demand. Happy New Year all, Doug -- Douglas E Powell doug...@gmail.com<mailto:doug...@gmail.com> http://www.linkedin.com/in/dougp01 - ---------------------------------------------------------------- This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. 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