gfci question

Status
Not open for further replies.
P

PMP

Member
Location
Delta, Colorado
I have a faceless gfi that trips properly when pushing the test button on the device itself, but when I plug a gfci tester into it, it trips immediately without pressing the test button. Anyone know what will cause this condition?
 
In my case it's usually my big fat thumb hitting the test button as I try to cram the tester into a tamper-resistant outlet while laying half under a hydro-tub :D
but as already asked, how does the tester work on other GFCI devices.
 
My Tasco "Inspector II" tester does that sometimes, usually if I reset GFCI and try again it doesn't trip the second time until I move switch to "GFCI Test"
 
The tester pulls a low current through the indicator lamps.
If the receptacle and/or GFI are miswired and the GFI is too sensitive the "normal" current could be tripping the GFI.
you can test the GFI with a higher ohm external resistor to check its sensitivity.
 
ActionDave said:
What happens to the gfi when you plug a load into it?
What happens when you plug the tester into a different gfi?
Click to expand...

when a load is plugged into it, it runs fine, the tester works perfectly in other GFIs, someone asked how do I plug into a faceless GFI, I assume that was an attempt at humor, obviously it was plugged into a recep fed by the load side of the faceless GFI.
 
PMP said:
when a load is plugged into it, it runs fine, the tester works perfectly in other GFIs, someone asked how do I plug into a faceless GFI, I assume that was an attempt at humor, obviously it was plugged into a recep fed by the load side of the faceless GFI.
Click to expand...

Every now and then someone makes an attempt at humor but usually it is forbidden, feeble or failed. One of those F words.
 
PMP said:
when a load is plugged into it, it runs fine, the tester works perfectly in other GFIs, someone asked how do I plug into a faceless GFI, I assume that was an attempt at humor, obviously it was plugged into a recep fed by the load side of the faceless GFI.
Click to expand...

A normal load does not have any significant current flow between hot and EGC. At most some capacitive leakage.
A simple neon bulb tester has a deliberate though small current from the hot to the EGC to light up the indicator.
Again it suggests that the threshold of the GFCI is abnormally low.
You could design a receptacle tester to be powered entirely (draw current only) by the voltage from hot to neutral, with all of the indications controlled by high impedance input voltage sensors feeding logic circuits.
But that would be unduly complex and would not give any indications at all for an open neutral. I do not know of any testers made in that way.
 
PMP said:
I have a faceless gfi that trips properly when pushing the test button on the device itself, but when I plug a gfci tester into it, it trips immediately without pressing the test button. Anyone know what will cause this condition?
Click to expand...

This is probably one reason why the only trustworthy test of a GFCI device is the test button. The threshold of the GFCI may be lower than the current the indicators of the tester are putting on it. At least one of the 'lights' on a plug in tester has to be connected to the ground pin in order to verify its existence. That may be enough to trip a very sensitive GFCI device.
 
PMP said:
when a load is plugged into it, it runs fine, the tester works perfectly in other GFIs,
Click to expand...
I agree with the others, sounds like an extra sensitve GFCI.
someone asked how do I plug into a faceless GFI, I assume that was an attempt at humor, obviously it was plugged into a recep fed by the load side of the faceless GFI.
Click to expand...
If you stick around you'll get good at sorting the good info from the bravo sierra pretty quick, and there is a lot more good info to be gathered here than there is of the other stuff. There has to be a little entertainment value or we might as well all sit around and watch training videos.
 
If the gfci only trips when the tester is plugged without pushing the test button then IMO you have a bad tester. I inferred from statements above that the gfci works fine with a load.
 
K8MHZ said:
This is probably one reason why the only trustworthy test of a GFCI device is the test button. The threshold of the GFCI may be lower than the current the indicators of the tester are putting on it. At least one of the 'lights' on a plug in tester has to be connected to the ground pin in order to verify its existence. That may be enough to trip a very sensitive GFCI device.
Click to expand...
If the GFCI trips at too low of a level it is defective, though it is more on the fail safe side when it comes to the reasons we have GFCI's.
 
kwired said:
If the GFCI trips at too low of a level it is defective, though it is more on the fail safe side when it comes to the reasons we have GFCI's.
Click to expand...

That may be true, but is using a 9 dollar ice cube tester an accurate means of determining what is 'too low'?

Maybe the tester is borderline, working on 'stiffer' but compliant devices, but not on this particular one. I sure wouldn't fail the GFCI based upon info from using a cheap tester that isn't even an approved means of testing.

To me, if it trips with the tester but works with a normal load, the GFCI is just doing its job. It may not be doing it like the directions on the tester say, but it is working.

Those little testers are handy, but shouldn't be trusted for accurate information. If true trip level data is needed, so is a better meter. If there are no nuisance trips and the device works fine when tested with its own button, the problem is likely with the tester, not the GFCI.
 
Status
Not open for further replies.
Top