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Receptacles - Ground Up or Ground Down? (9-23-99)
Mike, I have a question about installing 15 or 20 ampere, 125 volt receptacles. Is there any Code rule that says whether the receptacle should be installed with the ground opening at the bottom or at the top? I was told that it is better to put the ground at the top because it holds the plug in better and if the plug is pulled part way out, it prevents anything, like a paperclip or such from falling across and causing a short. I've looked through the NEC Code book and haven't found anything that specifies the direction for instillation. If you could give me an answer on this, it would be greatly appreciated.
Mike Holt's Comment:
WOW did I get mail on this on. Okay the voting was 38% it doesn't matter, 36% ground up, and 26% ground down. I have italicized some comments that I thought were very interesting.
Why the ground terminal should be up.
Electrical Safety
Ray Mullin RCMullin@aol.com
Author - Residential Wiring (Delmar Publishers)
Regarding the positioning of receptacles, here is the background of my stance
on this issue. A number of years ago, I had lunch with the Chief Electrical Engineer at McDonalds
headquarters. In the course of our discussion, he told me that one of the workers in one of their
stores had her hand badly burned. She let a metal cookie sheet (or something similar) slide out of
her hand. It fell onto a receptacle. An attachment plug cap was partially pulled out...so the metal
cookie sheet made contact with the two blades. A big arcing flash occurred.
Had the grounding slot been on the top, it is quite possible that the metal cookie sheet would have
bounced off...instead of causing a dangerous flash.
Later, I discussed this with Jack Wells of P&S. He thought it would be a good idea to require
that the grounding slot be on top of the receptacle. So I submitted a Code Proposal. It was rejected.
Jack and a few other CMP members were in favor...others were not. The proposal failed. But I believe
I just may have started something. If you check the current catalogs of P&S, Hubbell, Arrow-Hart,
and maybe others, you will find that the markings on the yoke (and on the GFCI reset and test buttons)
are readable when the ground slot is positioned on top.
In my texts Electrical Wiring - Residential and House Wiring With The NEC, I recommend that the ground
slot be positioned to the top when the receptacle is mounted vertical. When the receptacle is mounted
horizontally, I recommend that the wide (grounded conductor) slot be lace on top.
In either case, this offers a "last chance" that some metal falling onto the blades of a partially
pushed-in male attachment plug cap just might bounce off instead of causing a big flash. Mike, this
is one of my contributions to safety.
Alan Halberstadt alan.halberstadt@worldnet.att.net
I think a good reason for installing the receptacles with the ground up is that if you are using a
metal plate and the screw in it becomes loose, the plate doesn't fall across the hot and neutral.
I'm sure that it isn't a foolproof precaution, but I think that, combined with the other metal objects
I have read about falling across the two prongs, that they make a strong point for ground-up orientation.
We install horizontal receptacles with the neutral up for the same reason.
The only reasoning for ground-down orientation I have heard is:
1. "We've always done it that way"
2. It looks like a "happy-face" :-)
Bill wct1945@accessky.net
I don't believe there is a NEC section covering this. However, I like to install with the Ground Up.
Reason being, if anything metallic, especially a metallic cover should fall on a partially removed
plug the first thing it will contact is a GROUND. Hopefully that will prevent a shock by tripping
the breaker or opening the fuse.
Colin Croome colin@powerlink.net
The best that I have is the ground up will keep anything including the receptacle cover from falling across the terminals.
Dela,Sonny,GLENDALE,Engineering sonny.dela@us.nestle.com
In our standard drawing general notes, we also specifies the ground opening to be up and the reason I know is just like what Greg mentioned below - to minimize the possibility of short circuit if a metallic object fall and the plug is partly exposed.
I agree the Code does not address this issue. In thinking about it, the ground up would seem a better way to protect a picture frame, or any other thin, metal item sliding down the wall, perhaps behind a piece of furniture, from becoming energized. If a thin metal frame were to slide down, AND the attachment plug was partially pulled out, AND the receptacle was energized, AND the metal frame contacted the ungrounded conductor, AND someone were to touch it while being in contact with a grounded item, this could be deadly. I believe playing "what if" all day long could cause construction to cease and us spending our lives afraid to do anything as well. At any rate, with the ground up, if an attachment plug becomes partially dislodged and an item should be dropped or slide down the wall, a better chance of that item bouncing off, due to the triangular configuration of the prongs may present a safer installation.
I have a different philosophy for a horizontally mounted receptacle. With the grounded conductor (neutral) in the up position, even if an item should lie against it, electricity will follow the path of least resistance. Hopefully, this path is the conductor and not the person removing the item. I hope this makes sense. I look forward to comments.
Fredrick Rea O'Keefe fredrick@tech-center.com
Power Support Engineering, Inc. (Tampa, FL) endorses the "grounding pin on top" for mechanical and safety reasons. We are familiar with instances where electrical contractors have dropped metal items onto plugs not fully inserted into sockets.
Goodwin, Frank P. fpgoodwin@loopllc.com
I personally like the ground plug to the top for the shorting reason. Most of the time people will
want them with the ground facing down for the molded plugs on appliances usually face with the ground
this way. Left or right, now you're reaching out there. I guess I'll go with the ground facing left?
Why? Because I like it that way. This is one of those age-old questions that have no final answer.
Anyway my suggestion is ground top, or left on horizontal outlets. Thanks again for a good question
to spark interest in our trade.
Haskin, Donald M (DynCorp) HaskinDM@navair.navy.mil
While I don't think there is a code ruling on the orientation of a receptacle, I agree that orienting
the ground at the top may prevent a conducting object from coming into contact with the live parts.
However, since standard practice has been to install the ground down, so that the receptacle resembles
a "smiley face", many consumers will insist that you have installed their receptacles upside down
if we follow the more logical approach and install them ground up.
This subject came up on a job site a few days ago, and our top-gun made the call this way; If a metallic receptacle cover plate loses it's center fastening screw, the plate can now drop between the hot and neutral of the plug, shorting it out. With the ground on top, this would be prevented. We talked about it, and one of our guys had seen this happen as a result of an extension cord with too much tension on it.
Redwood Kardon redwood@codecheck.com
Here in California it is so much the standard that to indicate a receptacle is switched contractors will install the equipment ground up to distinguish it from the norm.
Robert Smith Robert.Smith@lpcorp.com
I have installed all the receptacles ground up since I went on a service call years ago. The reason
was very clear after seeing what happened to a child's toy. This toy was a remote control with wire
antenna. You guessed it; the child got electrocuted when the antenna made contact to the hot side.
Since that date I have been install ground up unless specified ground down. Anytime anyone has asks
why, I give the same explanation.
Skaff Jr., Thomas A. taskaff@nppd.com
The ground pin up would seem the logical way of preventing paper clips or other metal objects from shorting the hot & neutral. I kept an article from PowerCET Corp., by Mike Stringfellow that references IEEE Std. 602-1986 (Electric Systems in Health Care Facilities); I don't have a copy of it so I don't know the specifics. The horizontal configuration also seems logical to place the neutral up.
Mike Holt's Comment: IEEE Std. 602-1986 Electric Systems in Health Care Facilities does contain this as a recommended practice.
Steve Newell steven@panamax.com
I have personally seen, on two occasions, metal faceplates sliding between the receptacle and the AC cord plugged into it. This caused a good bit of arcing, etc. Fortunately, there was no major damage in either case. If the ground pin had been on the top, this wouldn't have happened.
Tim Connolly timceps@yahoo.com
There is no code that I am aware of that requires the ground prong to be on top. Although there are
many engineer specifications that give this requirement. It is my opinion that the ground prong mounted
on top offers an additional degree in safety from potential shock of shorted conditions. This is most
apparent if a metal plate is used and should become loose and fall across the partial exposed cord
prongs. Also if you look in most any manufacture catalog such as Hubble, P&S, Leviton etc., they
display the receptacles with the ground prong up! HUMMMMM, lets ask them why they do that.
Bob Ally bally2044@integrityonline14.com
Look at the manufacture's diagram on the back of the receptacle boxes, it shows the ground up!
The NEMA WD 6-88 (ANSI C73-73) shows the receptacle (5-15R) with the ground up. Many of the GFCI receptacles
are ground up. Yet all of the illustrations that I've seen in the NEC Handbook and in many other electrical
publications show the ground down. Orientation is moot since it still leaves open the question of
what direction the ground should be pointing (left or right) if the receptacle is placed horizontally
or what direction it should be pointing if the receptacle is installed in a ceiling. In absence of
other compelling data, I vote for ground up.
morcre morcre@netzero.net
Not required by Code to be in any particular direction, but look at the manufacturer's recommendations, that says the ground orientation should be up.
Wescoatt, Mike MWescoat@vegas.cirquedusoleil.com
A few years back I watched many manufacturers place the writing on the face of the receptacle so that
if the writing was oriented correctly the ground was at the top, I therefore thought that the ground
was intended by the manufacturer to be at the top. Hubbell produces its devices this way, and Pass
& Seymour prints a "TOP" label at the top of their devices which puts the ground at the top. Also,
perhaps more conclusive evidence, the NEMA North American Configuration Chart shows 5-15 and 5-20
configurations with the ground at the top. Perhaps in installation the resemblance to a face in the
"face" of the device prompted the vast majority of installers to place
the ground at the bottom, even if it is "wrong" by the NEMA chart. As for left vs. right, inconclusive
evidence on the packaging diagram of the Hubbell 5262 shows the ground to the right. And the debate
continues.
Mike Holt's Comment on Ground Up
No the NEC does not have any requirement for the orientation of the receptacle ground terminal. No the NEMA diagram does not apply. Device manufactures do not have requirements for the orientation of the ground terminal.
Note: I call Pass and Seymour a year ago on why they place the word "Top" on the metal mounting yoke of their receptacles. I spoke to an engineer there and they said that they recommended this practice. I ask her to send me something in writing. Her response was that they didn't have anything in writing.
Charles Cunningham CLC830@aol.com
I just got your message and would like to add my experience in the Navy. We found that installing the
ground up prevented the breakage of the plastic due to improper removal of the plug from the outlet
(pull on the cord from 20 feet away because I am lazy.) his reduced our work load by not having to
replace outlets so often.
Why the ground terminal should be down.
Dale Davis ddavis@biotecdental.com
I have mostly observed that they are installed with the ground lug down but I have no idea why.
I feel the 115 VAC receptacle should be installed with the ground pin on the bottom. This way the ground
is the last pin making contact, if or when the plugs "falls " out of the receptacle.
Joe Janowski jjanowsk@cisco.com
I've always put them in ground down, not sure why other than habit. I looked in my NEC Handbook and
saw them depicted with ground down and sideways but not up. Not sure why anyone (other than a child
maybe) would be playing with a paper clip that close to an electrical outlet but if they did it makes
sense.
Kelly JA_Kelly@email.msn.com
It is just a matter of preference. My preference is ground down or ground left. It is true that with
ground up any metallic object sliding down the wall will be less likely to cause any kind of fault.
This is also true with the ground to the left; an object would contact the neutral and grounding blades
of a plug not causing a short. I am anxious to hear you insight on the subject.
As an apprentice electrician, I was taught by several of the journeyman electricians that I worked
with to always install a 120-volt, straight-blade receptacle with the ground down. If the plug were
to partially pull out of the receptacle, the weight of the cord would tend to pull the plug down.
With the ground at the bottom, it would be the last prong to lose contact with the receptacle thus
providing an equipment ground to whatever was plugged in even if the hot and neutral prongs lost contact.
With the ground in the upper position, the ground prong on the plug could pull out with the hot and
neutral still energized, thus creating a possible electrocution hazard.
richard_anton_at_bnrpo1@mail.roe.com
Ground should be at bottom that way if the plug is accidentally pulled; the last prong to disconnect
will be the ground.
Richard_W_Cowburn@CNGT.CNG.COM
Mike, we have had some great talks about this topic and we all felt that its more important not to break the ground on a receptacles because that's what will take care of a short, so we like to install them with the ground prong down. It seems that plugs have a tendency to hang down so the ground prong is always connected. We know there are arguments both ways but this is how we install them. The ground prong is for personal safety so it if falls out first then there is no safety.
I feel that the ground opening on receptacles should be down. The tendency would be for the weight of the cord to pull down on the plug hence potentially exposing the live blade. While this in itself is unlikely, it is even less likely for some metal part to fall cross the blades. On the other hand, if the ground opening was up, potentially, the safety ground may be jeopardized causing a greater hazard.
Slye, Carl A (Homestead ARB) Carl.Slye@HST.AFRES.af.mil
This question has never been addressed in the electrical code as far as I know. Every electrician that
I know always puts the ground hole down. There are cases where turning the hole up will take the strain
off of an appliance cord. We use a proximity tester when doing a quick test of outlets. If the
grounding hole is up and the electrician isn't paying attention he or she may think there is no power
at the outlet.
Dale Rummer dprummer@falcon.cc.ukans.edu
It is my personal preference to install with the ground pin down because my receptacle tester has the
test result display on the topside when the receptacle is installed that way. Some testers however,
have the display on both sides, so that is not a consideration. The idea of installing it with the
ground pin up to avoid shorts from a paper clip sounds very reasonable. Perhaps I should get a two-sided
tester!
Dennis D. Hall dennis.hall@srs.gov
For 20 years I have been performing electrical maintenance in a very large government facility, which
includes lots of buildings. It is a policy on this site to mount all receptacles with the ground up
for all of the reasons mentioned in your newsletter. Here is the problem I have experienced as a result
of the "ground up" philosophy. Just about all equipment manufacturers install right angle attachment
plugs with the intent that the ground on the outlet will be
down. This results in undue stress on the cord and causes premature failure when these type of plugs
are installed "upside down". A lot of right replacement plugs, especially Hubbell brand, allow you
to install them either way. During my routine cord inspections and PM's I usually replace a lot of
factory right angle plugs for this reason.
Why it doesn't matter which way.
Charles McDaniel c m_mcd@mailcity.com
I have heard arguments both ways in my 35 years in the electrical industry. I have had people swear
that it was covered in the code although the exact article has never been shown to me. As recently
as two weeks ago some brought this up. I personally don't think it matters as long as the are all
turned in the same direction so as to be in a workman like manner.
David J. Duncan davidduncan@wwdb.org
I've had several discussions on this topic with Electricians and Inspectors, and surprisingly, I haven't been completely convinced that any one knows, which leads me to believe that there is no such code.
Earl Dean Earl21@ci.manchester.ct.us
I have always held the opinion that it doesn't really matter which direction the ground connection is. I have encountered angle cord caps that have the ground up, and down, and even to one side. In these cases (usually refrigerators or AC units) it was necessary to turn the receptacle over in order to have the cord lay flat. The NEC does not address this because there is no advantage to requiring the ground connection in any one direction. I encountered a Quad receptacle where there are four receptacle connectors on a single device, each facing a different direction!
I install my receptacles with the ground down (unless the cord requires it otherwise) because the
configuration looks like a face, and it bothers me to have upside down faces.
Gary Vencill gvencill@Chapel.com
I have to believe it is a 50 - 50 on preference. With the ground up, if the plug should work its way
loose you have the ground prong on top to protect an object from falling across the hot and neutral
prong. If the ground is down and the plug works it way loose the item that is plugged in is still
grounded protecting the user. Most healthcare facilities require ground up (IEEE Std. 602-1986 (Electric
Systems in Health Care Facilities).
james clites jimlavon@midwest.net
Since there appears to be no rule about how to install outlets, it seems installations should at least be consistent in a house, building, etc.--consistent installations are the mark of professionalism. Perhaps, consideration should be given to the design of the "three-prong plug-in" installed by many manufacturers on various pieces of equipment. It seems most are designed for "plugging-in" to outlets with the ground at the bottom.
In horizontal installation of outlets, I suggest a 90-degree rotation to the right placing the ground
entry hole on the left of the viewer: however, location of appliances and equipment could dictate
the opposite to accommodate the design of the cord "plug-in" head. My customers thank me for the consistency
of installation.
Jerry Snyder jsnyder@ctc.tec.pa.us
The NEC does not state the required orientation of receptacle. I've heard it said that if the ground
pin is down and the metal cover plate drop, it would hit the hot and neutral conductor and short the
circuit. Thirty years in the business and have never seen that happen. If you mount the ground pin
up and you plug in a right angle plug such as you find on a refrigerator or microwave you will have
the cord stressed in an upward direction and being pulled downward by gravity. I think it's time to
leave it the way it has been since we have had grounded receptacles. The general public has developed
this habit of turning the ground pin down to insert the plug.
I've heard the same argument about falling objects creating a short. Makes sense to me, but you lose
the cute little faces that you get with the ground at the bottom. To the right or to the left is a
royal pain created by architects with extra time on their hands.
JnHn@aol.com
If the trim plate is metal, the ground goes up to prevent a loose plate from shorting the circuit. If it's plastic it goes down.
Jody Wages jwages@admin1.siloamsprings.com
This has always been a reoccurring question in the electrical industry. Some believe that the receptacle
should be installed with the ground prong in the upward position. This makes it possible that anything
falling between the prongs will have a 50/50 change of contacting the grounding/ grounded conductor
verses the grounding/ ungrounded conductor. Some believe that the possibility of something making
contact with the grounded and ungrounded conductor prongs is negligible and the receptacle can be
installed with the ground prong down.
There are some jurisdictions that require the electrical contractor to install receptacles sideways
with the ungrounded conductor at the top. This would make it unlikely that the ungrounded conductor
would come in contact with any of the other conductors.
This will continue to be a question that arises in the industry. As long as there are electricians
and inspectors that have opinions on this subject, we will always have this discussion. Safety of
the electrical system should be everyone's concern, but alleviating all possible happenings within
the system will never be fully achieved.
John Hall tices@siscom.net
Being an inspector, I tell contractors I don't care which way you install the receptacle, I'll passed
it. Some contractor and inspectors insist on installing receptacles with the grounding lug up.
The story I get is: (if) a picture on the wall has a metal frame, and (if) the plug in the receptacle
is not all the way in the receptacle, and (if) the picture is above the receptacle, and (if) the picture
fall into the receptacle open space a short circuit will developed. Too many ifs for me to worry about.
John Lasher john.lasher@ae-systems.com
I feel up or down of the receptacle should be based upon the normal orientation or the devises using it. I have found with the ground up many of the devises have cords that are bent over at a 180-degree and I feel that puts undo stress on the cords and later fire hazard.
KEN TEVERBAUGH kbcjkt@worldnet.att.net
Hey Mike, I too have heard several different reasons for mounting the ground post both up, and down. The latest is in the down position, the reason: if the plug is pulled loose, or a short occurs, the ground post is the last to leave the receptacle. If mounted in the up position and the plug were pulled down, and out the ground would be the first to disconnect. Hope this helps.
EC&M in the McPartland era used to have a periodic discussion on this issue complete with photographs
and reader feedback. The contention is that the NEC DOES NOT specify orientation and as Greg has pointed
out, the strain is less on the blades. If a metal plate were to come loose, it would fall on the ground
and not cause a short circuit. Along with that line of reasoning they also suggested that when placing
a receptacle horizontally, place the ground opening to the left so that the same metal plate would
only fall on the grounded conductor thereby avoiding a fault condition. The only problem with this
of course is that 99.99% of all 120 Volt 3 wire molded cord caps I have ever see are designed with
the ground prong on the bottom (Air conditioner cords, refrigerators, etc.) and place a greater strain
on the assembly when inverted.
Nelson, Ron ronn@wrecc.com
Each installation needs to serve the plug-connected load properly. Some formed-plug extension cords
if plugged into a receptacle, will require the cord to point up, thus taking a 270-degree turn back
down the wall to the appliance. This requires the receptacle to be turned over as a good wiring practice.
Receptacles can be installed many ways therefore it is the responsibility of the electrician to know
the probable use. I've always heard the "grounding pin up" story, and I don't believe it makes a bit
of difference. Receptacles can be installed on the wall vertical or horizontal; it can also be installed
on the floor. In any case the circumstances will dictate the installation method.
Rex Cauldwell ltmtnele@swva.net
As it should be, there is no code reference as to which way the receptacle is to be mounted and I hope
there will be an electrician uprising if they ever attempt to create one. However, there is a code
reference to quality of workmanship..."Electric equipment shall be installed in a neat and workmanlike
manner." In my opinion this is a code violation of poor workmanship [110-12] if you install a receptacle
in such a manner that the plug cable has to go up and then reverse itself to go back down.
I've have seen several examples of ground down installations that turned out bad. Most involved the
use of metal cover plates. The metal cover plate had worked loose and fell down and across the hot
and neutral prongs....arc city. Because of this I never install metal cover plates, and I recommend
to all my customers to do likewise.
Mark V. Randazzo [mvrandazzo@netzero.net]
In response to Greg's question on installing grounding devices, I say...... Up, Down, Left, Right
and Inside-out. What's the difference? When I moved into my home all the devices were installed with
the ground up. What a pain in the neck when you have to plug in equipment with a polarized transformer.
I had to change them all. And how about those appliance cords that have the ground facing down. It
looks ugly with the cord running up the wall. I know that there are exceptions, but I think that there
are better things to be concerned about when installing devices safely. And I know that there are
good arguments to support both situations. I've heard them all. I believe that this should be left
to the Electrician at the time of installation. I've always said, "Aesthetics are 90 percent of the
Job".
Here in the Chicago area we put the outlets in horizontally wit the ground pins to the right to avoid
such problems. Thanks again for your newsletters!
Douglas Chaffin DAChaffin@lexcominc.net
My lead electrician said that by putting the ground in the down position, the plug would be more supported by the ground. Other veteran electricians I have worked with said just the opposite. Some have said that the writing on the receptacle determines the proper position. I'm guessing at this point that the proper way to install a receptacle is by personal preference of the customer.
Donald W. Zipse don.zip@dol.net
The answer is six of one and 1/2 doz. of another. There is no correct answer although most will mount
ground up, but if it causes the cord to twist it would be better to mount the ground down.
Mike Holt's Comment
I hope that by having this on the Internet this issue can be resolved. To me, the bottom line is:
- Specifications should require receptacles with metal cover plates to have the receptacle installed so the ground up.
- Specifications should indicate that the orientation of the receptacle should be in such a manner that stress will not be placed on the cord. If the grounding terminal is installed down, then plastic plates should be used.
- In health care facilities, the ground should be up.
- In all other installations it just doesn't matter. Do what the customer wants. Me personally, I want my grounds down in my house and I used plastic plates, but if I used metal plates, I would have the ground up.
P.S. My wife said she would prefer the ground up! I asked her why and she said that it would be easier to plug in the cord (better leverage) when the receptacle was low because the ground guided the other two prongs into the device. What about the kitchen counter top receptacles? She said it didn't matter if the ground was up or down (I'm still blown away because she is so picky on how the house matches, coordinates, and all that stuff.) So if I ever move and build a new home, the ground will be up (if she's not happy, nobody is happy). I really don't want to discuss this issue unless you have something new to add. I just hope I can put this "puppy" to sleep.
God Bless,
Mike Holt