Why is my GFCI breaker tripping??

[JS]

Our three bathrooms and one outdoor outlet are on one circuit with a GFCI
breaker.
When my wife uses a blowdryer in one of the the bathrooms, the GFCI
occassionally trips. I replaced the GFCI breaker, but it doesn't help.
Not knowing what else to do, I checked every outlet, but they all look fine.
I don't know what else to check. Could it be the blowdryer?
Any suggestions would be welcome.
I thought about putting a GFCI outlet in that bathroom, so at least she
wouldn't have to go down to the basement to reset it, but if it doesn't trip
the one built into the blowdryer, there is no reason to think that will
help. (I suppose I could replace all the outlets with GFCIs and the breaker
with a non-GFCI, but then I am looking at $60 plus time. I expect my wife
would say it was money well spent.)

 

[Speedy Jim]

Our three bathrooms and one outdoor outlet are on one circuit with a GFCI
breaker.
When my wife uses a blowdryer in one of the the bathrooms, the GFCI
occassionally trips. I replaced the GFCI breaker, but it doesn't help.
Not knowing what else to do, I checked every outlet, but they all look fine.
I don't know what else to check. Could it be the blowdryer?
Any suggestions would be welcome.
I thought about putting a GFCI outlet in that bathroom, so at least she
wouldn't have to go down to the basement to reset it, but if it doesn't trip
the one built into the blowdryer, there is no reason to think that will
help. (I suppose I could replace all the outlets with GFCIs and the breaker
with a non-GFCI, but then I am looking at $60 plus time. I expect my wife
would say it was money well spent.)

Try another hair dryer before you touch anything else.

Jim

 

[John Smith]

Try another hair dryer before you touch anything else.

Tried another hair dryer, same result. My wife claims that she plugs it in,
and it is dead. She must reset the breaker to get it to work. However,
then it always runs fine without tripping, until next time. The only other
things used in the circuit are two electric razors, and they run fine all
the time..
So, the problem seems to be turning on either of two blow dryers after not
using them for a day, in either of two outlets on the same GFCI breaker.

The breaker is 6 years old. I replaced another GFCI breaker when I had
problems that turned out to be a defective outlet.

This makes no sense at all to me. Please help!

 

[Jerry Levine]

snip<

I don't know if this will help or if it's your problem but let me tell you
my experience. I had a similiar problem and went crazy trying to find out
why. Then one of my neighbors told me they had the same problem and cured
it. Seems moisture was seeping into the outdoor outlet and causing the GFI
to trip. I ran a bead of cauling around the outdoor outlet and it never
happened again.

 

[MarineBob]

One other idea to consider. Especially if the box is crammed with wires, I have seen intermittent shorts just because things are so tight, occasionally a wire touches a screw lug on the fixture, like the GFI. I think most of them do a good job at filling available space in a box because they are on the larger size and you could have a wire randomly touching something.....maybe it heats a tiny bit when the hair dryer goes on and it moves ever so slightly? One easy fix aside from trying to fit ten pounds in a five pound box it to wrap the connectors with tape to insulate them when everything is squished back into the box. I have seen this a couple of times and it makes you pull your hair out.

 

[AC Power]

An an electrician, I agree with Jerry Levine's comment.

GFCI's operate by measuring the current leaving the circuit, and compare it with the current returning. If there is a difference of anything more than 5mA, the GFCI opens (trips). This is true both for a GFCI breaker, or a local GFCI receptacle. Your wife's blow-dryer likely only has two (2) conductors in its power cord (no ground). That's because there is nothing in a plastic device to ground....nothing is conductive in a hair dryer if it hasn't a metal chassis. Therefore, the hair dryer cannot produce any leakage current to ground.

Your problem is with the hard wired equipment (GFCI, razor outlet, moisture seeping into device boxes, etc...), not any portable consumer device.

 

[He who knows]

Doesn't a GFCI breaker also do ovecurrent protection, i.e. it's not just a Residual Current Device?

(Wikipedia says it is https://en.wikipedia.org/wiki/Resid...t_protection_circuitry_(RCBO_or_GFCI_breaker) )

In which case, is it possible to tell whether it's tripped because of overcurrent or leakage?

 

[AC Power]

@ "He who knows" = You could very well be right with regards the "overcurrent" feature....I never really thought about it. Good point though!

Your comment about visual indication of reason prompting opening? = Here in North America, our GFCI's simply have a RESET and PUSH-to-TEST manual pushbutton on their center face. The PUSH-to-TEST is for verification, and the RESET is depressed upon the GFCI opening the circuit for whatever reason. Our GFCI's don't differentiate and/or identify what prompted their response.

 

[He who knows]

Our RCBOs don't either. And it looks like we'll be going down the road of AFD as well, so there will be 3 conditions which will trip a breaker.