GFCI TEST BUTTON

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140428-1016 EDT

kwired:

Magnitude of flux change is the same but there is a difference in the current in the hot lead thru the current transformer.

When the test resistor is connected to hot on the output side, then the hot line current thru the current transformer under test conditions is greater than the neutral current. This is the real world case. When the test resistor lead passes thru the current transformer and terminates on the hot wire input side, then both hot and neutral wires have the same current. The flux is changed by the addition of the the third wire and the current thru it.

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gar said:
140428-1016 EDT

kwired:

Magnitude of flux change is the same but there is a difference in the current in the hot lead thru the current transformer.

When the test resistor is connected to hot on the output side, then the hot line current thru the current transformer under test conditions is greater than the neutral current. This is the real world case. When the test resistor lead passes thru the current transformer and terminates on the hot wire input side, then both hot and neutral wires have the same current. The flux is changed by the addition of the the third wire and the current thru it.

.
Click to expand...
You have lost me, or you didn't understand what I intended to say earlier. The test current passes through the CT either way on one side of the load and bypasses the CT on the other side of the load causing the unbalance necessary to cause current to flow in the CT and activate the trip circuitry.

K8MHZ said:
The ones that use magic don't have a test button. You use a wand, instead.
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Sounds like that would be easier test method, where can we get these?
 
K8MHZ said:
I noticed that one had 'solid state circuitry' indicated on it so we wouldn't confuse it with an old tube type GFCI.
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:D

Those where such a pain, they always got hot and melted the decora plates and waiting for them to warm up was time consuming.


FWIW I have worked on old transfer switches that had tubes. :jawdrop:
 
sarosa said:
The only way to properly and accurately check a GFCI receptacle is
with the test button on the device, not a GFCI plug tester
Click to expand...
That's going to be a tough concept to convey to EI's. What happens in cases of receptacles installed down-stream of the initial GFI receptacle ? Is the EI supposed to install his test device in one of those receptacles and then go back and push the button the the GFI receptacle to see if the lights on the tester go out ?
 
goldstar said:
That's going to be a tough concept to convey to EI's. What happens in cases of receptacles installed down-stream of the initial GFI receptacle ? Is the EI supposed to install his test device in one of those receptacles and then go back and push the button the the GFI receptacle to see if the lights on the tester go out ?
Click to expand...

They, us and everyone else is supposed to test GFCIs as the directions tell us and most directions will tell you to plug something into the down stream outlets and push the test button and see if it goes off.
 
sarosa said:
The only way to properly and accurately check a GFCI receptacle is
with the test button on the device, not a GFCI plug tester
Click to expand...
According to instructions included with the GFCI, probably true.

I still don't want to leave a GFCI in place that doesn't respond to a fault of the magnitude required to trip it whether it is done according to instructions or not, kind of like saying when a real hazard exists that the device was supposed to protect from that that hazard better know how to use the test button:happyyes:

If it doesn't trip with the external tester, but does trip with test button, one needs to verify correct polarity and continuity of each circuit conductor including the equipment grounding conductor. The test need not even be with a "tester" any applied load over 6mA outside the intended current path should trip it, if not something is not right with it.

goldstar said:
That's going to be a tough concept to convey to EI's. What happens in cases of receptacles installed down-stream of the initial GFI receptacle ? Is the EI supposed to install his test device in one of those receptacles and then go back and push the button the the GFI receptacle to see if the lights on the tester go out ?
Click to expand...
Hopefully if he does trip it from a downstream outlet he is nice enough to go back and reset it.
 
The only reason that an external tester should fail to trip a GFCI receptacle (or breaker) is if there is no EGC connection at the receptacle where it is plugged in.
No matter how many times you replace the GFCI receptacle you will not be able to find one that "works". :)

Tapatalk!
 
GoldDigger said:
The only reason that an external tester should fail to trip a GFCI receptacle (or breaker) is if there is no EGC connection at the receptacle where it is plugged in.
No matter how many times you replace the GFCI receptacle you will not be able to find one that "works". :)

Tapatalk!
Click to expand...

I disagree, if you are missing the ungrounded conductor I bet you have a hard time making it trip with the same tester:p

Of course if your tester has something wrong it may not trip either.
 
Service call yesterday, HI could trip bath GFCI's with test button but not with tester. I was ready to argue with him, until I found out both were connected to load terminals, nothing connected to line terminals (old style that will "work" that way).
 
readydave8 said:
Service call yesterday, HI could trip bath GFCI's with test button but not with tester. I was ready to argue with him, until I found out both were connected to load terminals, nothing connected to line terminals (old style that will "work" that way).
Click to expand...

That old style will also leave the receptacle energized when tripped if the supply is connected to the load terminals. New style can leave the outlet energized, but once you trip it it opens the load terminals from the outlet as well and will not reset without power on the line side terminals. When they are new they are in a trip state so that they will not reset if initial power up is applied to the load terminals, but take one that has been powered and as long as it was reset before removing power you can reapply power to the load side terminals and it will work fine until the next time it trips. Those newer features are not shown in any of the images that have been posted here.
 
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