Electrical Question

[Golden Mean]

The GFI in my case was tripping first. I never had a breaker trip the entire time.
The only thing that may be a puzzle is your understanding of the events. The mystery is solved and I get to have Wi-Fi enabled heat tape which was my goal.

Pretty sure GFI trips on current leakage/differential not current draw. My WAG is you have a device that's making it unhappy. Maybe the heat tape when it's wet outside? <shrug>

 

[COcheesehead]

Pretty sure GFI trips on current leakage/differential not current draw. My WAG is you have a device that's making it unhappy. Maybe the heat tape when it's wet outside? <shrug>

Probably the Wi-Fi outlet with both heat tapes plugged in. When we went to only one it worked. What complicated the diagnosis was the heavy duty three way that my builder used in the past. That didn’t play well with anything and yet I was trying to use it because it worked the last two winters. The only thing different was the outdoor Wi-Fi outlet.
In the end I am happy.

 

[misanman]

Just a wild guess but I'm thinking the problem isn't really solved and will come back. But I'm not an electrician so I probably should keep my mouth shut.

 

[COcheesehead]

Just a wild guess but I'm thinking the problem isn't really solved and will come back. But I'm not an electrician so I probably should keep my mouth shut.

We tested it while he was here and he checked the GFI and checked the breaker box.
I have been turning the heat tape on and off since Monday via the app.

 

[427Vette]

I am going to agree with others who say that this problem probably hasn’t been fixed, at least on purpose. To state it as simply as possible a gfci device will only trip on amperage loss to ground. It has no way of sensing if there are too many amps being pulled through it. It is the circuit breakers job to sense how many amps are allowed to flow through the outlets. Your breaker wasn’t tripping, the gfci was. Therefore you must have had an intermittent current leak. If the electrician took the devices in the circuit out of the boxes while doing some testing he could have inadvertently fixed the problem if there was a spot where a neutral wire was close enough to a ground wire to create a leak if there was a bit of moisture present. I suspect it was something to do with the 3 way switch you mentioned. Otherwise it seems that you have all of the same loads in the circuit as you did before. I am glad it’s working for you.

 

[COcheesehead]

The outlet has been in constant use since last Monday without issue.
Let’s give it a rest. In my mind the problem is solved. The journeyman electrician on site said it was solved as well.
I am now moving onto my next house project, refreshing my decomposed granite in my yard. I promise not to post a thread on that.

 

[Koolau]

The outlet has been in constant use since last Monday without issue.
Let’s give it a rest. In my mind the problem is solved. The journeyman electrician on site said it was solved as well.
I am now moving onto my next house project, refreshing my decomposed granite in my yard. I promise not to post a thread on that.

Promises, promises!


So glad you got if all figured out.

 

[Bruizer]

GFCI's can trip if they're overloaded. A circuit breaker typically has a delayed trip for small overloads. This is probably why the GFCI was tripping before the circuit breaker experienced a long enough overload to trip. Glad you got it resolved.

 

[ERD50]

GFCI's can trip if they're overloaded. A circuit breaker typically has a delayed trip for small overloads. This is probably why the GFCI was tripping before the circuit breaker experienced a long enough overload to trip. Glad you got it resolved.

Can you provide a source for that? The sources I listed do not support that (see my earlier post #47).

http://thecircuitdetective.com/home_electrical_myths.php

Home Electrical Myths

MYTH: A GFCI receptacle will trip off if you overload it (run too many watts).

This is not true at all. Only the circuit breaker in your electrical panel cares about the amount of load things are using. A GFCI is not at all sensitive to that, but it is very sensitive to electrical leaks AWAY FROM the path that loads (running things) use.

And here's the manufacturer technical data on a popular model:

https://www.leviton.com/en/products/gfnt2-rw

You'll note, the only trip/break spec is this:

Trip Level: Class A, 5mA plus or minus 1mA

And the 5mA is clearly a ground leakage limit, as that is only 0.005 Amps; 40,000x LESS than the 20 Amp breaker type spec.


I'm very curious to see if my info is wrong.


-ERD50

 

[Hermit]

After discussions with my county electrical inspector a couple of years ago, I was told I would be exceeding the 5 milliamp limit on GFCIs. He told me I would need GFPE interupters for my heat cables. According to the article below, NEC section 426-28 talks about requirements for fixed snow and ice melting equipment. You should be using roof heat cables, not the type of heat tape you would put around water pipes. You buy heat cable in watts per foot in either 120 or 240 volt cable. I think the 240 volt cable is usually used by electricians. GFPE breakers are pricey and go in the service panel. They should also be on a separate circuit. I have 3 separate circuits, one for each gutter run on my house. See the following article for more detailed info on GFPE, etc. The electrician should clue you in on all this stuff.



https://www.ecmag.com/magazine/arti...ndards-differences-between-gfci-idci-and-gfpe

 

[COcheesehead]

It’s not pipe tape. They are outdoor rated cables and have been successfully in use for three years.

 

[Koolau]

Can you provide a source for that? The sources I listed do not support that (see my earlier post #47).

Home Electrical Myths

Home Electrical Myths




And here's the manufacturer technical data on a popular model:

https://www.leviton.com/en/products/gfnt2-rw

You'll note, the only trip/break spec is this:



And the 5mA is clearly a ground leakage limit, as that is only 0.005 Amps; 40,000x LESS than the 20 Amp breaker type spec.


I'm very curious to see if my info is wrong.


-ERD50

Anecdotally, every couple or three months, our GFI on the kitchen counter trips when we turn on the toaster oven. DW starts jumping up and down and calls me to "fix it!" I tell her to wait 3 minutes and then push the reset button on the GFI. W*rks every time. Is that an overload? I don't know, but I would guess it is.

 

[ERD50]

Anecdotally, every couple or three months, our GFI on the kitchen counter trips when we turn on the toaster oven. DW starts jumping up and down and calls me to "fix it!" I tell her to wait 3 minutes and then push the reset button on the GFI. W*rks every time. Is that an overload? I don't know, but I would guess it is.

No. Standard GFI do not trip on 'overloads', that's the circuit breaker's job. A GFI trips on a Ground Fault, hence the name.

A Ground Fault means there is current flowing from the live/hot to ground. Normally, all the current flows from live/hot to Neutral. And current that doesn't return must be going somewhere else, typically ground (but it could also be flowing to the other phase). At any rate, a difference of 5mA between live/hot and Neutral will trip the GFI.

So even though you can have ~ 20 Amps flowing in-out of live/hot and neutral, it's pretty easy/cheap to detect an imbalance of 5 mA (1/40,000th of the main current), so these things are practical and affordable.

I'd guess you've got some crumbs or other food stuff that fell between the live/hot and some grounded part of the case. Is the toaster oven a three prong plug? If not, there is some other path to ground happening, probably NOT your wife, from what I understand you will feel 5 mA as a shock, but it trips fast enough to not harm you (no, I'm not going to test that!). Or maybe the GFI is just getting flaky, and false tripping?

Oh, I can't think of any reason to "wait 3 minutes", this isn't a thermal thing. It's an instantaneous measure of imbalance that opens the circuit, nothing 'lingers'. You can verify this yourself, push the TEST button, then immediately push the RESET button - power is ON, no waiting.

-ERD50

 

[ERD50]

SAFETY NOTE:

It's important to realize, you can still get a fatal shock from a GFI protected outlet.

If you come into contact with the live/hot side AND the Neutral side at the same time, the GFI will happily provide all the current required to fry you, just like it provides all the current to your toaster oven.

As long as all that current flows from hot to neutral, the GFI is satisfied. Only if you draw a lot of current, will the circuit breaker in the panel trip on the overload.

Also note, the specs on circuit breakers are complicated. The time to trip is dependent on how much of an overload there is. If you draw a few more than 20 Amps, it may NEVER trip, and some overloads can take hours to trip. It's only when you get into the higher currents that they trip fast (less than a second). Because these are thermal based, there is a time delay involved, and they have to avoid false tripping, so there is some added margin.

There is a secondary electromagnetic trip, which acts very fast on very high overloads.

-ERD50

 

[427Vette]

No. Standard GFI do not trip on 'overloads', that's the circuit breaker's job. A GFI trips on a Ground Fault, hence the name.

A Ground Fault means there is current flowing from the live/hot to ground. Normally, all the current flows from live/hot to Neutral. And current that doesn't return must be going somewhere else, typically ground (but it could also be flowing to the other phase). At any rate, a difference of 5mA between live/hot and Neutral will trip the GFI.

So even though you can have ~ 20 Amps flowing in-out of live/hot and neutral, it's pretty easy/cheap to detect an imbalance of 5 mA (1/40,000th of the main current), so these things are practical and affordable.

I'd guess you've got some crumbs or other food stuff that fell between the live/hot and some grounded part of the case. Is the toaster oven a three prong plug? If not, there is some other path to ground happening, probably NOT your wife, from what I understand you will feel 5 mA as a shock, but it trips fast enough to not harm you (no, I'm not going to test that!). Or maybe the GFI is just getting flaky, and false tripping?

Oh, I can't think of any reason to "wait 3 minutes", this isn't a thermal thing. It's an instantaneous measure of imbalance that opens the circuit, nothing 'lingers'. You can verify this yourself, push the TEST button, then immediately push the RESET button - power is ON, no waiting.

-ERD50

Wait a minute are you trying to say that a GFCI isn’t an overload device and won’t trip if it’s got to much current going through it?!?!?

Just kidding, excellent explanation.

 

[a60dan]

If the heat tapes are standing in water, it’s possible enough leakage current (I.e. current that is NOT returning from the hot to the neutral) is exceeding the very small mA limit and causing the GFCI to trip and open the circuit.

Ground Fault Circuit Interuptors (GFCI) can fail. If there is more than one on the same circuit, that can cause nuisance trips.

 

[Turbo29]

GFCI's can trip if they're overloaded. A circuit breaker typically has a delayed trip for small overloads. This is probably why the GFCI was tripping before the circuit breaker experienced a long enough overload to trip. Glad you got it resolved.

I am reading this thread with interest as I have a GFCI that only trips when the microwave or toaster oven is being used (either one takes ~1500W). Nothing else trips it. So it sure seems that drawing a lot of current through it is a contributing factor.

 

[ERD50]

I am reading this thread with interest as I have a GFCI that only trips when the microwave or toaster oven is being used (either one takes ~1500W). Nothing else trips it. So it sure seems that drawing a lot of current through it is a contributing factor.

Bzzzzt! Next contestant please!

Seriously, the amp draw has nothing to do with it, only Hot/Neutral imbalance.

-ERD50

 

[COcheesehead]

I just asked Google what trips a GFI. This is a word for word cut and paste.

One by one, plug in and turn on each device. When the GFCI trips, there are two possibilities: either the last appliance you plugged in is leaking electricity and causing a ground fault, or the number of devices is overloading the circuit.

 

[427Vette]

I just asked Google what trips a GFI. This is a word for word cut and paste.

One by one, plug in and turn on each device. When the GFCI trips, there are two possibilities: either the last appliance you plugged in is leaking electricity and causing a ground fault, or the number of devices is overloading the circuit.

Wait another minute…. Are you saying that everything you read on the internet is the gold standard rock solid truth? I am wondering if the person who wrote that has ever actually done any electrical troubleshooting. Do you think maybe one appliance has a current leak of 2 milliamps then another appliance has a leak of 3 milliamps then the GFI does it’s job and opens up the circuit at a total of 5 milliamps?

 

[ERD50]

I just asked Google what trips a GFI. This is a word for word cut and paste.

One by one, plug in and turn on each device. When the GFCI trips, there are two possibilities: either the last appliance you plugged in is leaking electricity and causing a ground fault, or the number of devices is overloading the circuit.

"Google" is not a "source", the internet is full of opinion/misinformation.

What is the make/model of your GFCI? We can check the spec sheet.

ooops, I see I cross-posted with 427Vette < "What that guy said!"

-ERD50

 

[427Vette]

"Google" is not a "source", the internet is full of opinion/misinformation.

What is the make/model of your GFCI? We can check the spec sheet.

ooops, I see I cross-posted with 427Vette < "What that guy said!"

-ERD50

Nope, you’ve got this. I am googling if “Edward Jones offers value to their clients”. Depending on what I learn I may be busy transferring finances for a bit.

 

[ERD50]

Nope, you’ve got this. I am googling if “Edward Jones offers value to their clients”. Depending on what I learn I may be busy transferring finances for a bit.

 

[427Vette]

5 Star Review By Lila
If you need a financial advisor, this is the place to go. They get to know what your goals are and help determine the best way for you to get there.

This is cut and pasted from google. It must be an upstanding ethical company.

 

[COcheesehead]

The shade tree electricians on here took a guess on my problem. They were all WRONG. Now they can’t believe they were wrong and talking stupid. Give it up boys. You’re just making yourself look silly. The problem is solved and not in anyway close to the suggestions on this thread. Such responses after the fact. Ouch. You should all be embarrassed. A new low for ER. My gosh. I appreciate the effort though.Happy Holidays.