Thread: Testing GFCI Outlets

I was trained to test GFCI outlets with both the integral test button and my "GFCI tester". A fairly sphisticated circuit analyzer I have from Cutler Hammer also states the proper way to test a GFCI is first with the test button and then with an external testor. It should trip either way. It is not unusual to find outlets that trip with the tester but not the test button. I have always noted them as deficient. Today I was challenged on one, and when I went to the internet for some research I found some sites that stated in fact that the only proper way to test them is with the integral test button, and that futhermore, testers often produce false results. It also said if not the tester that is wrong, the circuit may be wired with only two wires, which would be acceptable. One site was codecheck.com and the other was related to OSHA. So why do we have these testers? And aside from the outlets wired without an equipment ground, why do some not trip - yet they are supposedly OK?

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First, before addressing or asking anything else ...

Do you mean GFCI, or, do you mean ... AFCI.

It makes a big difference in the response regarding test method, and with the tester.

This is a plain old GFCI outlet. (We do not yet see AFCIs in Wisconsin, although I am familiar with them and have the analyzer to test them, for whenever we get around to requiring them here.) I just have trouble understanding: if 8 GFCI outlets in a fairly new house all test OK with the test buttons on the respective outlets, and 7 of the 8 trip with my plug-in tester, should I not have some suspicians about the one that does not trip? The websites I saw said apparrently not.

"This is a plain old GFCI outlet."

Okie-dokie, GFCIs it is.

The *best* way to test a GFCI is with the "Test" button on the GFCI device, however, another acceptable way is to use a proper GFCI tester, one which creates a 5 ma, plus or minus 1 ma, ground fault.

The more expensive circuit analyzers (like the SureTest, etc.) are and excellent choice for that remote testing of GFCI.

They (in the case of the SureTest) start out with a low ma ground fault and it goes up to 7 ma, showing the trip ma on the display after it trips (or shows 7 ma if it does not trip).

The catch with *ANY* GFCI tester which is not the internal GFCI test is that, for ungrounded circuits, *ANY OTHER* GFCI tester will not trip the GFCI mechanism.

The built-in test button will, ground or no ground.

"(We do not yet see AFCIs in Wisconsin, although I am familiar with them and have the analyzer to test them, for whenever we get around to requiring them here.)"

Actually, you do not have an analyzer to test them, none are made. There are, however, 'testers' (as some manufacturers of those devices call them, but which really on only *indicators*) are available to 'test' AFCIs and "indicate" if the AFCI trips (this next part of most important) *with the waveform created by the AFCI indicator". *IF* the AFCI does not trip on the AFCI "indicator" 'test', that does NOT mean the AFCI is bad or defective, it only means that that AFCI will not trip for that indicator.

For AFCIs, the *ONLY* "test" is the test button built-into the device.

"I just have trouble understanding: if 8 GFCI outlets in a fairly new house all test OK with the test buttons on the respective outlets, and 7 of the 8 trip with my plug-in tester, should I not have some suspicians about the one that does not trip?"

That does not trip ... how? Does not trip with your tester? Or does not trip with the GFCIs own test button.

If the GFCI does not trip with your tester, what ma is your tester saying it went to? Where are you plugging you tester in? Into the GFCI receptacle outlets themselves, or downstream from the GFCI device? It could be wired wrong (the older type was frequently mis-wired with Line and Load reversed, making the GFCIs not trip off properly.

If the GFCI does not trip with *ITS OWN* test button, it is defective.

Rodger
You asked... "So why do we have these testers? " (refering to GFCI testers).

use the tester on recepticals that are connected to the GFCI.

JERRY PECK,
I HAVE READ YOUR POSTS/REPLYS FOR THE PAST 4 YEARS. THIS ONE SOUNDS LIKE YOU ARE HANNIBAL LECHTER, WITH SO MANY QUESTIONS THAT CAN ONLY BE ANSWERED LOGICALY, BUT NEED TO BE FURTHER EVALUATED THAT ONLY DR. SPOCK CAN EVALUATE AS LOGICAL OR NON/LOGICAL????

Roger I have found that when I test GFCI outlets that have older wiring and are open ground outlets they will not trip with the button on my GFCI tester. So I have learned to not rely on the GFCI tester alone. I figure that if the GFCI trips with either the tester, the breaker, or the test button on the GFCI it is working properly.

Trent,

Belts and suspenders is not a bad idea, but it isn't necessary. The only test required to assure that the GFCI receptacle is functioning is the test button on the receptale.

Roger
The $12.00 test instruments most Inspectors carry are not worthless, but they frequently are used to test more than they are capable of or intended to test. (In my opinion, Jerry) they are good for testing if there is current to the receptacle you plug them into. You could use a lamp, but they're harder to fit into a pouch on your tool belt. Just like a lamp, they will tell you only if there is current present. On a two-pole circuit, they are functionally just like a lamp.

Unlike a lamp, at a grounded receptacle, they will, if functioning properly also identify reversed polarity conditions and whether or not that particular receptacle has the grounding conducor connected and functional. That is the extent of their worth.

As others have said, the testers have no value for testing GFCI protection on two-pole installations. They are not intended to. Some of the confusion comes from really bad wording in the instructions that come with them. Instead of saying "MAY not give an accurate reading on two pole circuits", the instructions should say "WILL not....."

The receptales down stream are just that; receptacles. They have GFCI protection derived from the GFCI receptacle. Start with the GFCI receptacle. Use its test button. If it trips, it's functioning. For everything down stream, plug in your tester. If it trips the GFCI receptacle, fine. If not, go back to the GFCI receptacle and use the test button. If you lose current to the receptacle you just were at, then that receptacle is GFCI protected and the GFCI is functioning. At that point, you are at the end of what you can test without better test equipment and a broader knowledge base.

So, Roger, yes you may have some suspisions, but you may not be able to confirm them. In the case above, using only the test equipment mentioned what you could not say is that "the GFCI protection is not functioning." What I think you could accurately say is "When testing for GFCI protection at the (identified) receptacle at the kitchen counter, GFCI protection was confirmed when using the test button at the GFCI receptacle. However, using (the named testing equipment) at the recptacle identified, I was unable to trip the GFCI protection from this one location. Anylizing the reasons for this result is beyond my capability. I have confirmed that polarity is correct and that a ground is present. All other receptacles tripped from their locations. I recommend that a licensed electrician diagnose the cause and make repairs as necessary."

Obviously, you don't want to have to make a recommendation for someone to spend money for an unnecessary repair, so buy the best equipment you can and get the best education you can. But accept that eventually you will reach the end of your knowledge base and will have to call the specialist.

Usually I test GFCI's both ways. First with my tester and then from the breaker at the outlet. If either way fails to trip the breaker I write it up.

If there is nothing out there to test AFCI's what is the test button on my Sure test for? I also check these the same as the GFCI's, from the button on the breaker and from the room. I did a house Saturday with 5 AFCI breakers installed. Four tested okay from the breakers one did not. When testing from the rooms 2 tested okay and 3 failed to trip. I wrote them up as defective especially the one that did not trip from either location.

I have a SureTest and it seldom comes out of its case.

I have found through my own personal experiences and from the knowledge of others that the best way to test a GFCI is with the built-in test button. Then to double check that it does not have current after it trips use a multi-meter or a voltage sniffer.

By doing it this way, you know that the device is working and you don't have to track down the GFCI that is hidden behind whatever the owner has stacked in front of it.

Originally Posted by Jerry Peck

The *best* way to test a GFCI is with the "Test" button on the GFCI device,

RANDY,

WHAT PART OF THAT DID YOU NOT UNDERSTAND?

I then went on to explain other testing methods and aspects of it for those who are interested.

(Sorry about the all caps ... er ... my 'Caps Lock' key got accidentally pushed. )

RANDY, IT IS BEST, WHEN TYPING ON A PUBLIC COMMUNICATION BOARD, TO NOT TYPE IN ALL CAPS, THAT TYPICALLY REPRESENTS 'YELLING', whereas normal typing does not.

My Dad types his e-mails in all caps, but that's so he can read it easier on his Pocket Mail he carries with him in his travels (he does not have, or want, a computer).