Ungrounded Electrical receptacles

Q:       The property inspector listed within his report that there were ungrounded electrical receptacles throughout the house. What is the difference between the ungrounded electrical receptacles being “throughout” the house and one or two ungrounded electrical receptacles? And, what can be done to correct this?

A:        There are typically two situations where ungrounded electrical receptacles will be present. The first is the sporadic presence of an ungrounded receptacle or circuit in a fully grounded system as a result of a loose grounding wire for one receptacle. If the receptacle that has a loose ground is the first in a circuit, the remaining electrical receptacles of the circuit will also be ungrounded. 

The second instance is when the complete electrical branch system of the house is ungrounded. This is common in most homes built prior to 1970 that had only a two wire ungrounded system and in homes pre 1960 where a knob-and-tube independent wire circuitry with no ground was used.

If the inspector described the presence of ungrounded electrical receptacles throughout the house in the report, it is very likely that the complete electrical system is ungrounded and three prong electrical receptacles have been installed at several locations. Another common trait of ungrounded systems is that the original electrical receptacles installed in this type of system were two prong electrical receptacles and in most cases, some of these two prong electrical receptacles will still be present behind furniture or inaccessible areas of the house.

Possible methods of correction:
In the first instance, identifying the loose grounding wire and reconnecting it will be all that is needed to correct an ungrounded receptacle.

To address the ungrounded electrical receptacles of a fully ungrounded system there are three options that the NEC ® allows.     

• 1. An equipment grounding wire can be installed attached to a water pipe at a point that is no further than 5 feet from where the metal underground pipe enters the structure.
  
• 2. Provide the receptacles with GFCI protection either by e device upstream in the circuit or by replacing the electrical receptacles with a GFCI receptacle. The electrical receptacles will need to be marked in either case as “No Equipment Ground.” This is an accepted replacement method because the GFCI electrical receptacles will cut power when a minimum change on the current of the neutral will trip the receptacle and cut all power to the receptacle, even without the ground. GFCI electrical outlets/receptacles cost around $8 to $12 each and are also easy to replace.
  
• 3. Replace the three prong ungrounded electrical receptacles with two prong electrical receptacles like the ones that were originally installed in the home when it was built. Two prong electrical receptacles are still readily available from places like Lowe’s and Home Depot and other neighborhood Hardware stores. This option has the second lowest price tag as these electrical receptacles can be easily replaced and only cost around $1.00 to $1.50 each.

What Not To Do!
Throughout times, some home owners, handymen, and even electricians have figured out that they can ground an outlet/receptacle by two different ways. One of them is by running a grounding wire from an ungrounded receptacle to a nearby metal water line. This would bring a ground to the receptacle. However, with the rapid change to using plastic lines for replacement of water systems, adding grounding wires to water lines is no longer accepted by the NEC unless the connection is done to the metal pipe no more than 5 feet away from the underground entry to the building. Grounding electrical receptacles or circuits directly to gas lines should never be performed either.

The second “clever” way is to add a jumping wire to the receptacle from the neutral side to the grounding connector. Some inspectors not familiar with this “trick” will actually miss this “false ground” condition and consider the electrical receptacles grounded because regular three light receptacle testers will read the receptacle as properly grounded.

False Ground: A "jump" wire connected from the ground to the neutral side.

  A qualified inspector will always check the electrical panels first as well as becoming knowledgeable about the age of the house to figure out if the electrical system is grounded or not. Seasoned inspectors will also carry special testers that can check for electrical receptacles with a “false ground.”

What can happen due to ungrounded electrical receptacles.
In a nutshell, a person can get shocked! Depending on the voltage and amperage current the person receives, reactions can range from feeling “tingly” and the heart stopping to sparks that could cause a fire if nearby flammables. Of course this is the worst case scenario and most typical home appliances will continue to work when connected to an ungrounded receptacle. However, the circuit or appliance will use the path of least resistance to transfer or discharge any electric load if a short or other malfunction occurs. The ground on a correctly grounded receptacle provides this path. If the ground is not available or is disconnected, the appliance may discharge through contact with a human being or any other available object that can transfer and/or discharge the electricity.

Who can perform the work.
Whenever electrical work is needed, a seasoned qualified electrician should always be hired. Electrocution is a real danger and some one with little or no knowledge of the basics of electricity should not attempt any repairs or work on the electrical system, especially if it is an older home where the conditions of concealed circuitry are unknown. One of the most common causes of fires in a home are caused by failing or malfunctioning electrical wiring or components.

For those people that understand electricity and can actually perform minor repairs, the use of protective clothing and equipment is strongly recommended. Additionally, having the right tool for the work can help perform the work safely.

John Chavez
www.AskHomepedia.com

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John Chavez is the founder and president of Nevada Home Inspection Group, Inc. established in 2000 in Carson City, NV and BLUEsky Home Services. He is a Nevada State Certified General Inspector of Structures and a former California State licensed general contractor. His construction (hands-on) experience spans over 22 years in all areas of commercial and residential construction throughout the United States.