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Commentary for Inspectors on two-wire, ungrounded systems

The following is a comment I use in my reports that addresses concerns about older two-wire systems:

"The home is wired with older two-wire, non-metallic sheathed cable, which was the norm when the home was built. These systems are generally functionally dependable, but are not up to modern safety standards. There is a greater risk of shock hazard with these systems; however, there are inexpensive steps that can be taken. I recommend evaluation by a licensed electrician, and strategic installation of GFCI (Ground Fault Circuit Interruptor) receptacles in wet locations such as kitchens, baths, laundry areas and outside receptacles."

Posted by Jimmy Breazeale on 03/19/2007 03:23 AM

Comments (23)

23 Comments on Commentary for Inspectors on two-wire, ungrounded systems

MAR

2007

Thank you Jimmy.That is the whole idea.Everybody contributes their wisdom so we all can learn.

The comment is don"t forget A F C I is now recommended in bedrooms.

Thanks, Bob...

The reason I recommend GFCI (even in the upstream receptacle in bedroom circuits) is that it affords a good measure of shock hazard protection, and it's cheaper to install than AFCI breakers. I have been mulling that over in my mind, though. Kind of waiting on the AFCI receptacle!! I make this recommendation because it's an inexpensive "update" that doesn't unnecessarily alarm clients (or their agents!!). Clients, especially those with small children, really appreciate the information.

I agree 100% just noting it is becoming required in new construction as they keep adding more and more protection devices to our homes.Guess that makes us needed more than ever. You were definatly correct in your recommendation for an older home.

MAR

2007

Jimmy

The two wire systems ARE grounded.

It is a wording thing.

I respectfully disagree that they are less safe than a 3 wire system.

Just look at your lamp, TV, clock radio.

AFCI receptacles would have to be installed within 6' of the panel.

Would the N E C agree with that comment.

I DO NOT want this to be seen as an insult.

From Article 90:

(C) Intention. This Code is not intended as a design specification

or an instruction manual for untrained persons.

Short answer is yes.

Thanks, Mike. I'll change the wording. However, GFCI will add a measure of protection against shock hazard.

Correction...wording is ok. I don't say those systems aren't grounded.

MAR

2007

Mike no insult intended here either.Maybe I miss read but my general impression is bedroom AFCI is a good choice. As far as two wire systems go you forgot to mention all those people using three prong adapters,are those safe?.are all those people mounting three hole receptacles on a two wire system also safe?

Your right! not for amateurs.
Arc Fault Circuit Interrupter http://www.cpsc.gov/CPSCPUB/PUBS/afcifac8.pdf
(AFCI)
FACT SHEET

THE AFCI

The "AFCI" is an arc fault circuit

interrupter. AFCIs are newly-developed

electrical devices designed to protect

against fires caused by arcing faults in the

home electrical wiring.

THE FIRE PROBLEM

Annually, over 40,000 fires are attributed

to home electrical wiring. These fires

result in over 350 deaths and over 1,400

injuries each year1. Arcing faults are one

of the major causes of these fires. When

unwanted arcing occurs, it generates high

temperatures that can ignite nearby

combustibles such as wood, paper, and

carpets.

Arcing faults often occur in damaged or

deteriorated wires and cords. Some causes

of damaged and deteriorated wiring include

puncturing of wire insulation from picture

hanging or cable staples, poorly installed

outlets or switches, cords caught in doors

or under furniture, furniture pushed against

plugs in an outlet, natural aging, and cord

exposure to heat vents and sunlight.

HOW THE AFCI WORKS

Conventional circuit breakers only respond to overloads and short circuits; so they do not

protect against arcing conditions that produce erratic current flow. An AFCI is selective

so that normal arcs do not cause it to trip.

The AFCI circuitry continuously monitors current flow through the AFCI. AFCIs use

unique current sensing circuitry to discriminate between normal and unwanted arcing

conditions. Once an unwanted arcing condition is detected, the control circuitry in the

1 Ault, Singh, and Smith, "1996 Residential Fire Loss Estimates", October 1998, U.S. Consumer

Product Safety Commission, Directorate for Epidemiology and Health Sciences.

AFCI trips the internal contacts, thus de-energizing the circuit and reducing the potential

for a fire to occur. An AFCI should not trip during normal arcing conditions, which can

occur when a switch is opened or a plug is pulled from a receptacle.

Presently, AFCIs are designed into conventional circuit breakers combining traditional

overload and short-circuit protection with arc fault protection. AFCI circuit breakers

(AFCIs) have a test button and look similar to ground fault circuit interrupter (GFCI)

circuit breakers. Some designs combine GFCI and AFCI protection. Additional AFCI

design configurations are anticipated in the near future.

It is important to note that AFCIs are designed to mitigate the effects of arcing faults but

cannot eliminate them completely. In some cases, the initial arc may cause ignition prior

to detection and circuit interruption by the AFCI.

The AFCI circuit breaker serves a dual purpose - not only will it shut off electricity in the

event of an "arcing fault", but it will also trip when a short circuit or an overload occurs.

The AFCI circuit breaker provides protection for the branch circuit wiring and limited

protection for power cords and extension cords. Single-pole, 15- and 20- ampere AFCI

circuit breakers are presently available.

WHERE AFCIs SHOULD BE USED

The 1999 edition of the National Electrical Code, the model code for electrical wiring

adopted by many local jurisdictions, requires AFCIs for receptacle outlets in bedrooms,

effective January 1, 2002. Although the requirement is limited to only certain circuits in

new residential construction, AFCIs should be considered for added protection in other

circuits and for existing homes as well. Older homes with aging and deteriorating wiring

systems can especially benefit from the added protection of AFCIs. AFCIs should also

be considered whenever adding or upgrading a panel box while using existing branch

circuit conductors.

INSTALLING AFCIs

AFCI circuit breakers should be installed by a qualified electrician. The installer should

follow the instructions accompanying the device and the panel box.

In homes equipped with conventional circuit breakers rather than fuses, an AFCI circuit

breaker may be installed in the panel box in place of the conventional circuit breaker to

add arc protection to a branch circuit. Homes with fuses are limited to receptacle or

portable-type AFCIs, which are expected to be available in the near future, or AFCI

circuit breakers can be added in separate panel boxes next to the fuse panel box.

TESTING AN AFCI

AFCIs should be tested after installation to make sure they are working properly and

protecting the circuit. Subsequently, AFCIs should be tested once a month to make sure

they are working properly and providing protection from fires initiated by arcing faults.

A test button is located on the front of the device. The user should follow the instructions

accompanying the device. If the device does not trip when tested, the AFCI is defective

and should be replaced.

AFCIs vs. GFCIs

The AFCI should not be confused with the GFCI or ground fault circuit interrupter. The

GFCI is designed to protect people from severe or fatal electric shocks while the AFCI

protects against fires caused by arcing faults. The GFCI also can protect against some

electrical fires by detecting arcing and other faults to ground but cannot detect hazardous

across-the-line arcing faults that can cause fires.

A ground fault is an unintentional electric path diverting current to ground. Ground

faults occur when current leaks from a circuit. How the current leaks is very important.

If a person's body provides a path to ground for this leakage, the person could be injured,

burned, severely shocked, or electrocuted.

The National Electrical Code requires GFCI protection for receptacles located outdoors;

in bathrooms, garages, kitchens, crawl spaces and unfinished basements; and at certain

locations such as near swimming pools. A combination AFCI and GFCI can be used to

satisfy the NEC requirement for GFCI protection only if specifically marked as a

combination device.

I am trying to get you to say the equipment grounding conductor.

Ha Ha...Nit Picky.Just trying to figure more on the 6 foot comment could you elaborate.

LOL!! Let me simplify this for you guys. I am NOT saying that AFCI isn't a better choice for bedrooms. It is. I'm not saying two wire systems aren't grounded. I'm just saying that there is nothing wrong with actually using a GFCI receptacle for ADDED shock hazard protection in an older home (if installed on the upstream receptacle of any circuit), and that it is a CHEAPER alternative. That's all. People buying older homes who have small children and slimmer budgets appreciate this. WHEN the AFCI RECEPTACLE is invented, I will make that recommendation.

Or is this just an "Ohio" thing I should stay out of??? :-)

Jimmy he just wanted to pry the proper tech terminology (grounding electrode) out of you.So next time you publish if we see the word (sub panel )WATCH OUT.As far as any remodeling goes it is now recommened that AFCI is installed.Of coarse we have no power to enforce Thank God.

LOL!! I get it, guys!!

Who luvs ya! speaking of which, what happened to Deal Breaker.

Deal breaker is still going on. Neurotic Desiree seems to still be of the opinion that inspectors are dummies. Inspectors have pretty much quit bashing each other. Some pretty good comments from agents/realtors overall.

APR

2007

Bob

The branch circuit must be AFCI protected not just the outlets (rectp,switches, lights, smokes ,the wire).

Article 210 Branch circuits.

Gee, Mike!!! There's nothing in the NEC that says one can not place a GFCI upstream (and I"m not talking new construction here) of any circuit for a little added shock hazard protection in those old two wire systems. Upgrading to AFCI is, of course, the best thing to do....but it's not the least expensive thing to do. Bear in mind that sellers, in these instances, are not required to do ANYTHING, and neither is the buyer. We all know that most people will just let well enough alone, and use the three prong adaptors for lack of better information. And you know there are still lots of appliances out there where one runs the risk of becoming the equipment ground. Just trying to keep a few more kiddies a little safer. Is there a reason NOT to make a recommendation such as the one I suggested? Do you think I should change the language to include more info on AFCI?

Jimmy

I was talking about AFCI's.

You are correct. Article 406 backs you up.

Actually I just thought it might good to mention it as a side bar for the educational benefit to the client and not as a pre-requisite.You know,just an rap talk on how it protects against fire verses the GFCI protects people thang.

I used to do that, Bob. I started making the recommendation (I don't list it as a defect) because I really felt that it would go in one ear and out the other. Especially young couples....but when they have kids, they tend to remember, and they've got it written down.

Thanks, Mike. I kinda thought we were really on the same page. But I think I probably will change the language to include the AFCI option.

JUN

2008

Complicated stuff. Jimmy Breazeale (Sherlock Home Inspections) Is this the same Jim Breazeale who worked with the RTC during the 1990's?

RTC....hmmmm...if you mean to say RTS in Jackson, Ms, then yes, I am he. Who dis?

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