GFCI Tripping on Inrush

[haskindm]

It is well known that any circuit that incorporates integrated circuits can fail if exposed to a certain level of electrical noise or RF fields. GFCIs included.

Then this is still not nuisance tripping. In such a case is it OK to eliminate NEC required GFCI protection because "noise" causes the device to trip? I think not. A device with a higher tolerance of noise, or a way to reduce the noise to which the device is exposed will need to be found. This would be a case of equipment not "suitable for the environment" being installed which would be a violation of 110.3. A way will need to be found to ensure that the requirements of the NEC are met and that the device operates properly. This may include using a different brand of device, relocating the equipment, etc. "Nuisance Tripping" cannot and should not be used as an excuse to violate the NEC.

 

[masterelect1]

So in the case where the breaker trips due to noise it is not considered defective but instead not immune enough for the level of noise it is exposed to.

As one example I had a 3 phase GFI tripping intermittently. It was replaced twice with the same manufacturers brand and continued to trip. We then replaced it with a different model that had specifically been tested for noise immunity and it held fine.


QUOTE]

You have just disputed your own contention that nuisance tripping is "for real"

The breaker was not "suitable" for the application to which it was applied, therefore it tripped. Re-read your post and you may understand the fallacy of your statement.

 

[wptski]

Okay, all you anti-nuisance tripping generation, for which "everything" has a cause unless your too lazy or too dumb to find the cause! How much does the "perfect" GFCI breaker/receptacle, immune to "all" cost and how big is it now??

 

[haskindm]

Cost is not the issue, complying with the NEC is. If the device is not suitable for the environment, it cannot be installed in that environment. Just as you can't install a non-explosion proof device in an environment that requires explosion proof devices or a non damp-location device in a damp location. The device is not defective, it is not appropriate, and steps will need to be taken to either install an appropriate device or change the environment. Just because something is difficult or expensive does not mean we can violate the NEC either. There was a discussion lately about a kitchen equipment manufacturer that included instructions prohibiting their cord and plug connected equipment from being installed on a ground fault protected circuit. That does NOT give you permission to install a non GFCI protected receptacle in a commercial kitchen. That just means that manufacturers equipment cannot be installed in a commercial kitchen where GFCI is an NEC requirement. If that is enforced as it should be, that manufacturer will quickly find a way to make its products compatible with GFCI.

 

[ELA]

Then this is still not nuisance tripping. In such a case is it OK to eliminate NEC required GFCI protection because "noise" causes the device to trip? I think not. A device with a higher tolerance of noise, or a way to reduce the noise to which the device is exposed will need to be found. This would be a case of equipment not "suitable for the environment" being installed which would be a violation of 110.3. A way will need to be found to ensure that the requirements of the NEC are met and that the device operates properly. This may include using a different brand of device, relocating the equipment, etc. "Nuisance Tripping" cannot and should not be used as an excuse to violate the NEC.

Please re-read the first line of my post!
Then next check the site I referenced where the manufacturer confirms that GFCI's "false trip".

In instances where a GFCI is required, and they false trip, the solution is indeed a better quality GFCI designed to better withstand electrial noise (as I pointed out). Or you could also filter out the source of the noise.

The issue here is that early on manufacturers didn't understand that they needed to design-in better noise immunity. Use of these devices in industrial environments quickly pointed out their lack of immunity. Manufacturers are getting better.
I still maintain that when a GFCI trips due to noise it is a nuisance (or false) trip.

 

[tom baker]

The newest UL standard for GFCIs requires a higher immunity to RF noise.
Most GFCI trips are due to ground faults, and not a GFCI malfuction.

 

[ELA]

So in the case where the breaker trips due to noise it is not considered defective but instead not immune enough for the level of noise it is exposed to.

As one example I had a 3 phase GFI tripping intermittently. It was replaced twice with the same manufacturers brand and continued to trip. We then replaced it with a different model that had specifically been tested for noise immunity and it held fine.


QUOTE]

You have just disputed your own contention that nuisance tripping is "for real"

The breaker was not "suitable" for the application to which it was applied, therefore it tripped. Re-read your post and you may understand the fallacy of your statement.

Sorry but your logic escapes me. And your tone .....

Any given part may perform just fine in a design in 98% of the applications where installed. Then in 2% it may fail due to the presence of a larger than normally encountered electrical interference level.
The usual solution would be to filter or eliminate the source of the noise.
In the example I cited the customer was not willing to find the source and filter it so we had to do extensive research to locate a more robust breaker.

Unless equipment is required to undergo extensive EMC testing (like it is when required to be CE marked) then you may never know there is an issue until it is installed in an electrically noisy environment.

Manufacturers may not always know in advance what the noise levels at an installation site may be.

Take another example:
RF from hand held radios are notorious for inducing currents into electrical equipment and causing upsets. And yes they can cause a GFCI to trip.
So a given piece of equipment uses a GFCI that performs just fine up until when a service person keys up a radio in the vacinity of the breaker and it trips. This is a nuisance trip.

The breaker is reset and never fails again during its lifetime (provided not exposed to a high level of noise).

Nuisance tripping is very real and you would know that if you understood EM compliance.

 

[haskindm]

Again I disagree with the term nuisance tripping. When the GFCI tripped due to radio interference, you knew why it tripped. The fix is easy, find a Breaker that is more resistant to RF signals, shield the breaker from RF signals, or somehow prevent the use of RF producing devices in the vicinity of the breaker, or accept the fact that, on occasion, this breaker will need to be reset due to RF interference. I maintain that you cannot eliminate NEC required protection because of "nuisance tripping". Most people use the term nuisance tripping for unexplained, unrepairable breaker tripping and then come up with all sorts of non-NEC compliant "fixes". Remove the GFCI protection, install over-sized breakers, etc. This is what I am trying to avoid.

 

[wptski]

Cost is not the issue, complying with the NEC is. If the device is not suitable for the environment, it cannot be installed in that environment. Just as you can't install a non-explosion proof device in an environment that requires explosion proof devices or a non damp-location device in a damp location. The device is not defective, it is not appropriate, and steps will need to be taken to either install an appropriate device or change the environment. Just because something is difficult or expensive does not mean we can violate the NEC either. There was a discussion lately about a kitchen equipment manufacturer that included instructions prohibiting their cord and plug connected equipment from being installed on a ground fault protected circuit. That does NOT give you permission to install a non GFCI protected receptacle in a commercial kitchen. That just means that manufacturers equipment cannot be installed in a commercial kitchen where GFCI is an NEC requirement. If that is enforced as it should be, that manufacturer will quickly find a way to make its products compatible with GFCI.

Not everybody has to comply with NEC! Do you think that all work is inspected? That ones that don't comply with beloved NEC won't replace a receptacle with a GFCI type if it cost too much even though it's safer.

 

[wwhitney]

I maintain that you cannot eliminate NEC required protection because of "nuisance tripping".

Why do you conflate "nuisance tripping" with "eliminating the GFCI"? I think many people would say that tripping due to RF interference is "nuisance" tripping, but hopefully few of them would suggest removing the GFCI when it is required.

Cheers, Wayne

 

[haskindm]

Compliance with the NEC should not be dependant on the work being inspected. The NEC is a widely recognized, readily available, minimum standard. Anyone who does electrical work, whether or not it is inspected, or whether or not the jurisdiction accepts and enforces the NEC, had better be following some standard. If not, when something happens, there is no legal defense other than "In my opinion, it was good enough". Personally, I would rather say, "My installation complied with the latest edition of the NEC, which is a recognized standard for electrical installations". Those of you that have been told that you do not need to follow the NEC are exposing yourself to great liability if you do not do so.
Most often I hear the term "nuisance tripping" being used as an excuse to violate the NEC, usually by removing GFCI protection. I know this is not always the case, but many times it is. I told my class just this past week about the exception for non-GFCI receptacles in a garage for an appliance being eliminated in the 2008 NEC. I had a student get very upset and state that he will "NEVER" install a GFCI receptacle for a refrigerator or freezer, regardless of what the NEC states, because it may "nuisance trip". That is the attitude that I am against.

 

[wptski]

Compliance with the NEC should not be dependant on the work being inspected. The NEC is a widely recognized, readily available, minimum standard. Anyone who does electrical work, whether or not it is inspected, or whether or not the jurisdiction accepts and enforces the NEC, had better be following some standard. If not, when something happens, there is no legal defense other than "In my opinion, it was good enough". Personally, I would rather say, "My installation complied with the latest edition of the NEC, which is a recognized standard for electrical installations". Those of you that have been told that you do not need to follow the NEC are exposing yourself to great liability if you do not do so.
Most often I hear the term "nuisance tripping" being used as an excuse to violate the NEC, usually by removing GFCI protection. I know this is not always the case, but many times it is. I told my class just this past week about the exception for non-GFCI receptacles in a garage for an appliance being eliminated in the 2008 NEC. I had a student get very upset and state that he will "NEVER" install a GFCI receptacle for a refrigerator or freezer, regardless of what the NEC states, because it may "nuisance trip". That is the attitude that I am against.

An average home owner that does their own electrical work has never heard of NEC and therefore not comply!

 

[haskindm]

In most jurisdictions the average home owner doing his own work is in violation of state law. In most counties in Maryland a homeowner may do electrical work in their own home only after passing a "homeowners exam" which demonstrates their understanding of the NEC and electrical theory. Ignorance is no excuse. Being unaware of the NEC does not give a person the right to violate it.

 

[tallguy]

In most jurisdictions the average home owner doing his own work is in violation of state law. In most counties in Maryland a homeowner may do electrical work in their own home only after passing a "homeowners exam" which demonstrates their understanding of the NEC and electrical theory. Ignorance is no excuse. Being unaware of the NEC does not give a person the right to violate it.

NH allows owner-occupied to do own work. No test.

 

[wptski]

In most jurisdictions the average home owner doing his own work is in violation of state law. In most counties in Maryland a homeowner may do electrical work in their own home only after passing a "homeowners exam" which demonstrates their understanding of the NEC and electrical theory. Ignorance is no excuse. Being unaware of the NEC does not give a person the right to violate it.

Of all the "real" laws violated every second, you think anybody really worried about replacing a light switch?? C'mon!! It's like putting your trash out too early!

 

[winnie]

This discussion is already getting rather toasty, but I'd like to throw in my 0.02 toward finding a middle ground.

I believe that we are talking from different _reasonable_ definitions of 'nuisance tripping', and also presenting different approaches to dealing with it.

Nuisance tripping could variously be defined as:
1) Tripping of a circuit protective device when an 'insignificant' fault exists.
2) Tripping of a circuit protective device when no actual fault exists, but instead on expected and _acceptable_ transient conditions.
3) Tripping of a circuit protective device due to external interference, or other 'random' tripping.
4) Tripping of a circuit protective device due to a real fault, but where there is nothing to fix.
and I am sure a few others that I've missed.

The approach to dealing with 'nuisance tripping' could be any of the following:
a) Eliminate some form of circuit protection.
b) Fix the load in question
c) Adjust the circuit protection trip levels to better match the expected load conditions.
d) Change the rules associated with circuit protection devices to better match the 'real world'.

In my opinion, nuisance tripping described in 2 and 3 above exists, and adjustment to deal with it is _not_ necessarily a violation of the NEC, but instead a _design issue_. A GFCI that is excessively sensitive to radio frequency interference is IMHO not an NEC violation, and any RFI induced trips are nuisance trips. In my opinion, an RFI immune GFCI is a good design choice, but not mandated by the NEC. Eliminating a required GFCI because of RFI induced trips would of course be an NEC violation.

Short duration overloads and startup transients are an expected and acceptable aspect of circuit operation. OCPD have current versus time characteristics which take this into account, and various aspects of the NEC specifically make allowance for these conditions. See, for example, the maximum OCPD permitted on the primary side of a transformer, or providing circuit protection for a motor. In my opinion, OCPD which is properly sized for the continuous operation of a load and for protection of the circuit conductors is sufficient to meet the _requirements_ of the NEC. In the range of such _acceptable_ OCPD, some devices will trip on the transient conditions, others will not. In my opinion, when an NEC acceptable OCPD trips on normal transient conditions, than that is a nuisance trip. Changing to a different acceptable OCPD that is immune to these normal transients is a good design choice, but not required. Eliminating a required OCPD because of transient induced trips is of course an NEC violation.

With 'combination' AFCIs, we are going to see an interesting discussion of nuisance tripping. Arcs are a normal and expected aspect of circuit operation. Switches and brush motors arc. The arcing is expected and designed for, and is not a safety concern. Combination AFCIs are supposed to detect series arcs which are faults, while at the same time ignoring series arcs which are intentional aspects of the circuit. In the design of the AFCI, there will always be a trade-off between sensitivity to arc faults, and immunity to intentional arcs. This means that AFCIs will always have to balance real 'nuisance tripping' (when the AFCI detects and trips on an _intentional_ arc) and protection (when the AFCI detects a series arc.)

Finally I'd like to close with some general agreement with haskindm: very often the appearance of 'nuisance tripping' is used as an excuse to eliminate protection, and very often this nuisance tripping is a real fault. GFCIs are becoming more reliable, and insulation systems are getting much better. With a modern GFCI and a modern refrigerator, if the GFCI trips, it is almost certainly because something is _broken_, and not because of some small but acceptable leakage through the insulation.

-Jon

 

[wptski]

Now that's BS, make a statement, lock the thread, unlock it so one more can make another statement and then decide to leave it unlocked! Make up your mind.

Or is it?? Locked but allows editing? Maybe that's half-locked, hey?

Anyway since I can edit, unless you delete this. If you choose to lock a thread, just do it and not unlock it for your buddies for one more last statement because that's unprofessional!!

 

[iwire]

Now that's BS, make a statement, lock the thread, unlock it so one more can make the last statement anjd lock it again!

Is it locked now?

Yes, I unlocked the thread for winnie, that is because I knew winnie could maintain a professional tone. This thread had been going down hill.

 

[ADAMA]

Inrush

Inrush

I called for a 120 volt 20 amp receptacle in a commercial juice bar to be GFCI protected. The refrigerator in this location trips the breaker and the manufacturer says it is due to inrush. I thought this problem had been resolved with newer GFCI receptacles.

What experiences are others having recently?

Thanks

Jim T

From ADAMA usually what I will do is replace it with a Single receptacle

 

[iwire]

From ADAMA usually what I will do is replace it with a Single receptacle

That is not an NEC acceptable solution except in basements and garages of dwelling units and once the 2008 NEC is adopted it will not be acceptable in any location.