Grounded vs. Non-Grounded Outlets

By
Real Estate Agent with The AmyBSells Team - Keller Williams Advisors

As I go about representing my buyers as an ABR, I find the same topics surfacing each time my clients go through a Whole House Inspection. The issue of the grounded and not grounded outlets. What does it mean, what are they used for, and what happens if they aren't grounded. After weeks of begging for simple answers to this question, I give you my trusted Licensed Whole House Inspectors response...

Amy,
In response to your questions pertaining to receptacles commonly found in residential homes I will start with the basics of the old and the new. First, though I would like to identify that I am a licensed home inspector, however for any electrical work and advice on electrical systems I recommend my customers consult with a licensed electrician as needed.

Homes built prior to the early 1960’s were most commonly wired with a two-wire system, absent of the modern third wire being an equipment ground wire. The first requirement for grounded receptacles in residential construction dates back to 1951 when the NEC® (National Electrical Code) required laundry areas to have grounded receptacles. Devices and locations have been added to this requirement until the grounded system is a requirement throughout a modern residential home.

  • Electrical devices that can be used with non grounded receptacles are: lamps, radios, power adapters, toasters, vacuum cleaners and any item that the cord does not have the round third prong.
  • Electrical devices that require a grounded receptacle (equipment ground) are: high-end appliances, computers, TV’s, stereo equipment, power tools, surge protector strips and any other electrical device with the cord having the third prong.

Adapters are available that allow for a device using a three prong/ground to be utilized in a two slot receptacle. The adapters are inserted into a two-prong receptacle and then the adapter spade is secured to the receptacle with the center screw of the cover plate. For these adapters to be functional, the grounding of the receptacle body and box is required.

Homes prior to the 1960's that have not been updated will most commonly have two slot receptacles. Most homes that were built prior to the 1960’s have gone through some form or another of modernizing/upgrading the electrical system within the home. Non-grounded outlet
A non-grounded Outlet The most common is the replacement of the two slot receptacles with the three prong (grounded) receptacles. When the installation of the grounded receptacle is correct, the receptacle provides an equipment ground utilizing the round hoe in the receptacle. Incorrectly installed the ground is not present commonly referred to as an open ground. This will not provide an equipment ground and high-end equipment/computers/TV's should not be used on this receptacle with an open ground.

In the event that a high-end device such as a computer plugged into an ungrounded receptacle, the performance of the device may never be affected or problems detected. However the device can be damaged without warning at any time from static electricity that has no way of being discharged as well as another source of voltage coming in contact (lightning could be one). This can originate from various sources internal as well as external of the device. The idea of the ground is to trip the breaker preventing damage to the device or electrical shock to the user. If the device is not properly grounded, and any of a number of events occurs, the device may be damaged beyond economical repair. I have found in a few warranties stating that a device used with a non-grounded receptacle is not covered under the manufacturers warranty; this is for the same reasons as previously identified.

A surge protector used at a non-grounded receptacle is a glorified extension cord, and provides no additional protection, only a false sense of protection. Using an adapter with the metal spade secured under the faceplate screw is not a ground unless you check it for grounding and grounding is confirmed. Most sources do not suggest these adapters to be “permanently” installed as a solution to grounding. Again, these devices if not properly grounded can provide the user with a false since of grounding.

In older homes open grounds are quite commonly found, this is due to the original wiring systems not being upgraded to a three wire system or only selective areas being upgraded. The methods of grounding these receptacles vary greatly dependent on the period when they were installed or upgraded.
A grounded outlet
A grounded Outlet.When three prong receptacles with open grounds are identified and a two-wire system is present, the NEC® currently allows the following methods to be used to resolve the problem:

  • Install an equipment ground. (recommended for high end equipment, see previous comments)
  • Provide GFCI protection for the receptacle (either at the receptacle or upstream of the receptacle) the receptacles are to be marked “no equipment ground”. This method does not provide an equipment ground.
  • Replace the existing three-hole receptacle with a two-hole non-grounded receptacle.

Polarized plugs have two different sized slots, the neutral is the larger slot, this allows for a device to be plugged in, in only one manner insuring correct polarity. Reversed polarity is when the common and hot wire is reversed on the receptacle; when this occurs the large blade receptacle is now hot rather than neutral (this applies to both grounded and non grounded systems). As an example a lamp is plugged in with the polarity reversed, the exterior metal light bulb socket is “hot” at all times. In this instance when changing the bulb or touching the exterior of the socket the individual can be shocked. Reverse polarity is a safety issue and can cause problems with high-end appliances.

Reversed polarity is usually simple to repair. Quite often, if multiple receptacles check for reverse polarity it is not uncommon for only one wiring termination to be incorrect. However this can not be determined without further investigation.

Ground Fault Circuit Interrupters (GFCI’s) are intended to protect the individuals using an electrical device particularly in a wet area. GFCI’s are available as circuit breakers located within a service panel and as a receptacle. Most home owners are familiar with these as the receptacle with the little buttons (test and reset buttons) that seem to always trip when using the hair dryer.
GFCI Outlet
GFCI Outlet.The GFCI provides protection to the user and is tripped by sensing current leak/imbalance in turn shutting of the power to the electrical device. The GFCI does not trip by detection of amperage like a circuit breaker, and in tern, a standard breaker does not trip under the same circumstances that a GFCI will trip.

GFCI’s are a safety item and provides protection from electrical shock and potential electrocution. The GFCI’s are intended to be tested by the homeowner once a month to insure function. GFCI’s can be installed on both a two wire system without a ground and a three wire system.

GFCI’s are required by the NEC© in various areas, the following is a general list (not complete) of when and where: 1971 exterior receptacles and swimming pool areas, 1975 Bathrooms, 1978 garages, 1981 whirlpools and tubs, 1987 kitchens within 6’ of the sink and basements, 1990 unfinished basements and crawl spaces, 1993 wet bars sinks, 1996 all kitchen counter receptacles, dedicated bathroom circuits, all outdoor receptacles, electric car chargers.

In the event that a GFCI does not function properly, the GFCI should be repaired for safety. In older homes where GFCI’s are not present, I recommend that GFCI’s be installed for safety, this would normally be considered an improvement to the property.

A three-bulb receptacle tester is most commonly used during a home inspection to determine if receptacles are wired properly. This device is readily available at most hardware stores and can be used by a homeowner normally. The use of this device alone is not a replacement of the services of a qualified electrician.

Michael Patton is a Licensed Home Inspector and the owner operator of AA Home Inspection LLC located in Northern Kentucky. Michael is licensed in Kentucky and Indiana and qualified to perform inspections in Ohio (Ohio does not have a licensing requirement). Michael is the current President of the Kentucky Real Estate Inspectors Association Inc. (KREIA) and an active member of the American Society of Home Inspectors (ASHI). Michael started AA Home Inspection LLC in 2001, prior to this Michael had worked for firms providing a wide range of services including design, construction, and project management. Michael’s services include Residential Home Inspections, Light Commercial Inspections, WDI/Termite Inspections, and Radon Testing. The Greater Cincinnati area provides a wide variety of inspections; from the million dollar properties to the fixer upper homes, new construction to homes well over one hundred years old and clients from the well established to the first time homebuyers.

www.AAHomeInspection.net

Comments (29)

Anonymous
Eugene J. Pinder
I wonder what would happen in a two wire system if you were to install gfci,s PLUS run a short jumper wire from the neutral to the ground lug on the receptacles?
Mar 09, 2007 10:20 AM
#1
Mike (Inspector Mike) Parks
Inspector Mike - Circleville, OH
Inspector Mike

"I wonder what would happen in a two wire system if you were to install gfci,s PLUS run a short
jumper wire from the neutral to the ground lug on the receptacles?"

Not allowed.

You may use a GFCI and attach the label "no equipment ground". You may add regular outlets down stream from the GFCI and attach the above labeling.

Do not be confused the older 2-wire outlets DO have a ground and are safe. Look at the plug on your lamp, TV, clock radio, etc. However they will not accept the newer 3 prong plugs.

 

Mar 11, 2007 06:53 AM
Anonymous
Paul W. Abernathy ( www.TheElectricalGuru.com )

Also it would put objectionable currents onto the grounding/bonding system...simply not something you would wish to do on purpose.

Dec 06, 2007 07:32 AM
#3
Anonymous
ITM
WHAT WOULD HAPPEN IF A EXTERIOR MOTION LIGHT WAS INSTALLED WITHOUT THE GROUNDING WIRE SECURED?
Jan 07, 2008 07:38 AM
#4
Anonymous
john hammar
If I am understanding the correct procedure I will need to run a ground wire to the areas in the kitchen, bath,wash room where I have two prong and need three for GFI installation.  Also in any room which uses a three prong appliance such as tv, computer I would also need to run the additional ground wire.  Thanks for your reply.
Apr 22, 2008 06:24 PM
#5
Anonymous
Matthew
Hi, I have a 3 prong outlet that doesn't seem to be grounded properly. I had my computer hooked up to it and when I would touch the metal part of my headphones (or any metal part of my computer / device attached to my computer), I would recieve a continued shock. Is this a problem with my outlet, my home's wiring or something else?
May 04, 2008 08:17 AM
#7
Mike (Inspector Mike) Parks
Inspector Mike - Circleville, OH
Inspector Mike

Mathew

Could be either. CALL an electrician.

May 04, 2008 10:57 PM
Anonymous
frank jr

I am repairing an older home and i need to replace a switch and plug combo that is non grounded and I can not find a single store that sell it. If someone could please help me I would be very thankful Frank.

Aug 13, 2008 04:14 PM
#9
Anonymous
Anthony

I have a home built in 91 and just had my home inspected. The inspector states open grounds on 3 prong outlets. There has been no electrical work done to any of these outlets. Does this mean the ground wire just wasn't attached when insatlled, or can ther be 2 wire in parts of thehouse and 2 wire in other parts? Thanks for help.

Aug 22, 2008 02:46 AM
#10
Mike (Inspector Mike) Parks
Inspector Mike - Circleville, OH
Inspector Mike

Sounds like the EGC (equipment grounding conductor) is not attached or brocken.

Aug 22, 2008 03:47 AM
Anonymous
James Miller

We live in a bi-level home built in 1977.  All the outlets upstairs are 3-prong grounded.  All the rooms on the lower level with the exception of the laundry room are 3-prong non-grounded.  Could they be 2-wire grounded?

May 25, 2011 10:25 AM
#12
Anonymous
James Miller

We live in a bi-level home built in 1977.  All the outlets upstairs are 3-prong grounded.  All the rooms on the lower level (which is mostly below ground level) with the exception of the laundry room are 3-prong non-grounded.  We have lived there for 19 years with TV and multi-computer hookups.  We have never experienced any problems with static electricity/shocks.  Being in Michigan all of my 70 years I have never experience any problems, whatsoever, to speak of.  I was raised on the next street over from where we are presently.  The home was built around 1940 with no grounding.  It is still there, and from the condition of it I doubt seriously if it was ever upgraded to gounding.  In matter of fact, this sub-division of six roads has been here since the 30's, and as far as I know there has been no home destroyed by fire.  
I personally think that this matter of grounding has been an overkill.  What are the chances of a home being destroyed as a result of no grounding?

Mar 17, 2012 04:21 AM
#13
xukaimin1 xukaimin1
shfdg - Hartly, DE


reebok

supra

nike roshe run

wedding dresses

jordan retro

moncler

wedding dresses

air max 2017

tommy hilfiger

jordan 3

swarovski

herve leger

beats headphones

nike roshe run

ugg boots

new balance trainer

lebron 11

ray ban

canada goose

new balance shoes

uggs

longchamp handbags

ghd

yeezy shoe

christian louboutin

oakley sunglasses

timberland boots

converse

ugg boots

adidas flip-flops

nike store

converse

furla handbags

hogan

nike air

sac burberry

ugg

huarache

nike air max

reebok

mac cosmetics

omega watches

brazil world cup jersey

jordan

fitflop

kenzo clothing

adidas uk

cheap eyeglasses

nike outlet

nike blazer

moncler jackets

nike free

nike blazer pas cher

ray ban sunglasses

guess

soccer jerseys

tommy hilfiger

spain world cup jersey

longchamp

red bottoms

uggs outlet

vanessa bruno

new balance

burberry outlet online

vans

versace handbags

ralph lauren

tods shoes

canada goose

nike air max plus

roty burch outlet

mizuno running shoes

nike air max

ralph lauren

adidas clothing

tory burch outlet

canada goose

polo ralph lauren

air max

dansko

nike roshe run pas cher

jordan xx9

dolce and gabbana

pandora jewelry

sac longchamp

cheap ugg boots

oakley

ralph lauren outlet

moncler jackets

jordan 12

north face

kobe 9

burberry outlet

ralph lauren

nike air force

lebron shoes

baseball bats

mac makeup

wedding dresses

louboutin pas cher

air max 97

roshe run

ugg boots

nike clothing

ray ban

nike free

nike shoes

jerseys

michael kors

parajumpers

jordans

michael kors

adidas outlet

moncler outlet

barbour

canada goose jackets

ugg boots

adidas trainers

nike store

links of london

nike shoes

ray ban outlet

england world cup jersey

jordans

ugg

puma shoes

valentino

air jordan

air max 2017

ralph lauren

true religion jeans

new balance

nike air max 2018

coach outlet

ugg

michael kors outlet

montre pas cher

rolex

new balance

polo ralph lauren

reebok

nike air force

fendi

air max

vans shoes

adidas outlet

adidas outlet

nike air max

salomon shoes

belgium world cup jerseys

replica watches

boy london clothing

nike free run

jordan shoes

ray ban sunglasses

rolex

nike mercurial

vans

argentina world cup jersey

new balance

sac guess

nike free

jordan shoes

converse

canada goose

burberry outlet

longchamp

coach outlet online

ray ban sunglasses

asics

jordan 11

rolex watches

asics

ugg australia

mac makeup

giuseppe zanotti

timberland

air jordans

fendi

uggs outlet

nike air

michael kors

softball bats

michael kors

prada outlet

nike air max

mulberry

air max 95

uggs outlet

oakley sunglasses

portugal world cup jersey

louboutin

nike mercurial

cheap uggs

moncler

ferragamo

jordans

flops

marc jacobs

louboutin

oakley sunglasses

kate spade outlet

oakley vault

ray ban

oakley

north face outlet

longchamp

north face pas cher

miu miu shoes

michael kors canada

north face

nike air max

jordan

beats by dre

nike tn

true religion

moncler

adidas outlet

swarovski uk

jordans

guess

oakley

nike store

pandora

moncler

oakley sunglasses

flip flops

michael kors borse

nike air max

nike vapor max

true religion outlet

mizuno wave

ugg

new balance

roshe run

nike outlet

basketball shoes

ed hardy

chloe handbags

ferragamo

bottega veneta

mulberry outlet

chrome hearts

michael kors outlet

the north face

cheap nfl jerseys

louboutin

roshe run

montre homme

cartier love bracelet

hogan outlet

jordan shoes

kevin durant shoes

germany world cup jersey

timberland boots

mac cosmetics

cheap nfl jerseys

oakley sunglasses cheap

free run

clarks shoes

adidas zx

louboutin

timberland

jordan 4

timberland

instyler ionic styler

nike air force

air max

michael kors outlet

michael kors outlet

nike kyrie 2

thomas sabo

nike air max

coach outlet

roty burch outlet online

nike air

hermes outlet

adidas

ray ban

hermes

kate spade outlet

ralph lauren outlet

ugg boots

converse shoes

beats by dre

skechers shoes

salvatore ferragamo

karen millen uk

jimmy choo

marc jacobs

oakley vault

air max

stuart weitzman

adidas superstar

michael kors outlet online store

nike blazer

yves saint laurent

michael kors

prada outlet

north face

adidas outlet

true religion jeans

adidas running shoes

sac michael kors

nike shoes

vans shoes

bottega

stuart weitzman

converse

nike air max

birkin bag

oakley sunglasses

manolo blahnik

canada goose outlet

ralph lauren uk

dolce and gabbana

bcbg

iphone cases

nike outlet

nike

nike air max 95

jordan

nike air max

montre

michael kors outlet

the north face

canada goose

lacoste shoes

pandora jewelry

jordan 5

louboutin

nike free

iphone 7 cases

adidas soccer cleats

longchamp handbags

bcbg max

mont blanc

fivefingers

asics

pandora

dansko shoes

polo lacoste

hogan shoes

ray ban

coach purse

kate spade

goyard handbags

swarovski

burberry outlet

canada goose jackets

ugg outlet

tommy hilfiger

iphone x case

new balance

roshe run

true religion jeans

flip flops

lebron james shoes

soccer shoes

ugg australia

france world cup jersey

converse chuck taylor

air max

balenciaga

louboutin

jordan

nike air huarache

adidas slides

pandora

bottes ugg

asics gel

air max 90

ray ban sunglasses

rolex watches

jordan 6

wedding dresses

nike air max

jordan 1

swarovski

montblanc

mizuno

kobe 10

polo ralph lauren

pandora charms

supra

prada

longchamp

true religion outlet

nike free

celine

2018.3.22xukaimin

Mar 21, 2018 10:52 PM

What's the reason you're reporting this blog entry?

Are you sure you want to report this blog entry as spam?