# GFCI breaker - that sensitive?



## geospec (May 23, 2009)

More than a year ago, we installed a whirlpool for a client in a remodeling project. The existing main electrical panel has few extra slots to accommodate the three new 15 amps GFCI (Murray Type MP-GT) breakers. We ran six #14 wires (three black and three white and using the metal conduit as ground) inside the new metal conduit from the panel to the metal receptacle box that houses three standard 15 amps outlets for the whirlpool to connect to. This setup has been running without any trouble for the past year.

We got a call back from the owner that recently one of the GFCI breakers at the panel is tripping constantly. I went to the jobsite to check it out and found that one of the three breakers was tripping. I check all the wires and even replaced the outlets at the receptacle box and tested the circuit with a GFCI tester. Everything was working fine for the first 15 minutes. After 15 minutes, the GFCI breaker tripped again. I disconnected the load at the other end and reset the GFCI breaker at the main panel. After few minutes later, the GFCI breaker tripped again without any load.

I have installed many GFCI receptacles at the receptacle box and this is my first experience with GFCI breakers. Are these GFCI breakers that sensitive?


----------



## We Fix Houses (Aug 15, 2007)

Did you also check the screws on the buss bar of your new circuits ?


----------



## 480sparky (Feb 1, 2009)

When you disconnected the load, did you just unplug the cords?

If so, there may be a problem with the conductors themselves or something at the receptacles. Try taking them off the breaker itself.

If that fails, replace the breaker is it's defective.


PS. It always amazes me when people have the 'it worked fine for years' attitude. My water heater worked fine for years........ until it quit. My roof worked fine for years....... until it leaked. My truck brakes worked fine for years........ until the pads wore out. All things man-made are mechanical and will eventually fail.


----------



## thom (Nov 3, 2006)

480sparky said:


> PS. It always amazes me when people have the 'it worked fine for years' attitude. My water heater worked fine for years........ until it quit. My roof worked fine for years....... until it leaked. My truck brakes worked fine for years........ until the pads wore out. All things man-made are mechanical and will eventually fail.


Ahhhhhh.................................... That explains it. I've been wondering what the problem is, and what to do. Now I know. It's time to replace the failed wife with a new one. :whistling


----------



## CookeCarpentry (Feb 26, 2009)

thom said:


> Ahhhhhh.................................... That explains it. I've been wondering what the problem is, and what to do. Now I know. It's time to replace the failed wife with a new one. :whistling


It'll cost you.......:laughing:


----------



## Leo G (May 12, 2005)

CookeCarpentry said:


> It'll cost you.......:laughing:



Half of everything you got....:whistling


----------



## geospec (May 23, 2009)

I looked at the screws at the buzz bar and it looks OK. But I did not tighten it.

I disconnected the whirlpool plugs and even replaced the outlets with new ones. 

I didn't have any new GFCI breakers with me and I neglected to exchange the existing GFCI breakers with each other for testing.

I tested the circuits with the GFCI tester and every circuit was OK.

I reset the GFCI breaker and it worked for more than 15 minutes without tripping it. After 15 minutes, it tripped again. 

This is what is bothering me! Can anyone explain this phenomena?


----------



## Leo G (May 12, 2005)

Sounds like a bad breaker.


----------



## CookeCarpentry (Feb 26, 2009)

geospec said:


> Can anyone explain this phenomena?


First off, material and/or product failures do not fall into the "phenomena" category.

Unless the ghost of Abe Lincoln is switching the breaker off, try replacing with a new breaker, or get an exorcist.


----------



## We Fix Houses (Aug 15, 2007)

***


----------



## 480sparky (Feb 1, 2009)

CookeCarpentry said:


> First off, material and/or product failures do not fall into the "phenomena" category.
> 
> Unless the ghost of Abe Lincoln is switching the breaker off, try replacing with a new breaker, or get an exorcist.










​


----------



## woodchuck2 (Feb 27, 2008)

If you are doubting the idea of a bad breaker "which i also believe it is" then swap it with one of the other two so it is under a different load. If it still trips then replace it.


----------



## Electricmanscot (Feb 6, 2005)

geospec said:


> I looked at the screws at the buzz bar and it looks OK. But I did not tighten it.


Ok, the fact that you called it a "buzz bar" is all I need to know. :laughing:


----------



## Tinstaafl (Jan 6, 2008)

Electricmanscot said:


> Ok, the fact that you called it a "buzz bar" is all I need to know. :laughing:


Hey, they do buzz sometimes... :laughing:


----------



## geospec (May 23, 2009)

Thank you all for your positive professional replies. 

I am trying to find out what makes a GFCI circuit breaker to trip or malfunction:

(1) Is it due to the constant checking of the current flowing to the load with the current coming from the load? If this is the case, the GFCI breaker is working fine and is performing its proper function.

(2) If the breaker mechanism is malfunctioning, is it caused by the thermal fatigue cycling in the circuit which leads to premature failure on the contact gap in the breaker mechanism?

(3) Is it caused by the corrosion at the junction points in the circuit exposed to the environment? Usually the ground connection is the culprit in this case!


----------

