AFCI Nuisance tripping.

[darekelec]

hi smartest electricians on planet earth!
i have a case of nuisance tripping of cutler hammer combination type breakers. i have a bunch of them in breaker box but only those serving lutron rpm modules of homeworks system are tripping on completely unpredictable basis. i started to believe in extraterrestrials when trying to determine the cause of tripping. i checked all wiring using afci breaker and gfci load side in lutron panel and they are 100% correct.
with 5 breakers afci comination type (br20caf i believe) i feed 7 rpm 4U's modules in lutron panel. those modules energize mostly lucifer led down lights.
do you have any experience in afci combination type nuisance tripping?
from what i remember there may be factors like: first afci were recommended to be spaced cause the internal electronics generated heat which made them to trip, brush type power tools used to trip afcis.
maybe you can direct me to lighting control or similar forum cause this is not strictly NEC issue apart from the fact installation has to be free of shorts and stuff like that
client wants to move in couple of days.
penny for your thought
thank you in advance

 

[mbrooke]

Nearly every single full time residential service electrician will see this. First step for me would be to unplug all the plug in devices and go from there. If you have a mega-ohm meter test the circuit for any ground neutral or phase faults. If none are present try another AFCI, preferebly a latter model and see how it performs. No simple way to put it but you will have to do forensics both on the circuit or the appliances plugged in to see whats causeing it. And no, while an unwritten issue with older AFCIs, you dont have to have them on every other stab or so forth. They are designed to be stacked on top of one another without tripping or overheating. Newer AFCIs however do perform better than the older ones, but your ok either way.


You mentioned a client moving in, does this mean an AFCI is tripping without anything plugged in? If so thats actually a good thing in that Half your worry is gone.


This might help to start:


http://static.schneider-electric.us...ture Circuit Breakers/Homeline/0760DB0201.pdf

 

[ELA]

Did you check the load compatibility list for the 4u's?
LEDs often require certain types of drivers for ELV.

 

[darekelec]

re plug in appliances - there are not present as my breakers feed light control system modules
re ELA's question - i have 4U's that power light fixtures that contain led drivers. manufacturer recommends using of mr16 phillips led bulbs that we are using.
it just makes me wonder how much electronics are involved in equivalent of wolfram filament.

 

[mbrooke]

AFCIs and electronic equipment dont always mix, but first megger the circuit to rule that out of the equation.

 

[darekelec]

what's megering the circuit? i got 1 fancy electric measuring tool. would i have to disconnect the led drivers in light fixtures?

 

[mbrooke]

Before meggering wires ALWAYS disconnect the load especially if its electronic. A megger is a megaohmmeter, wich is really an ohm meter on steroids. The purpose of it will be to test the wiring for faults or insulation nicks. A neutral to ground fault will not trip a regular breaker, but will trip an AFCI. Same with an arc fault from damaged insulation or loose connection. The megger is just to show that neutral, ground and hot are all insulated from each other.


Once the wiring checks out ok then the issue moves on to the electronic drivers and such. But before doing anything to the electronics try changing the arc fault breaker, could be just a bad batch.

http://en.wikipedia.org/wiki/Megohmmeter

 

[ActionDave]

do you have any experience in afci combination type nuisance tripping?

AFCIs and electronic equipment dont always mix....

There is answer right there. Combo type AFCI's and electronic loads will not get along.

Contact the manufacturer. They may be able to send you a newer model breaker, or you can tell them your problem so they can start making one.

 

[darekelec]

yeah, I got that tool. i test old chandeliers with it.
i have a new name for this problem - nonsense tripping :happyno:

 

[kwired]

yeah, I got that tool. i test old chandeliers with it.
i have a new name for this problem - nonsense tripping :happyno:

You maybe come to a new realization, but trust me, somewhere someone is probably well ahead of you with getting a trademark for that name for this reason:happyyes:

 

[Jbird66]

We had a smiliar problem with a couple Lutron Graphic Eye panels last year. We ended up calling Lutron and they sent us new panels and that fixed it.

Wow I feel your pain for sure. It is always hard trouble shooting when you cant replicate the problem.

 

[ELA]

It took me a while to find the compatibility list for your 4u's. It was here:
http://www.lutron.com/technicaldocumentlibrary/3682994a_CFL%20LED%20Bulb%20list_Resi%20Systems.pdf

The MR16 did not show up on that list?

As others have said many electronic devices generate EMI that can upset AFCI's.

Can you try using incandescent lamps temporarily as a test? To determine if the load type is at issue. It is possible that more EMI is generated with an LED load than an Incandescent due to what is referred to as "repetitive inrush current".

You could also try an EMI filter to isolate the loads from the breaker, if nothing else as a test.

Best of luck to you.
CFL's and LED's sure do make things much more complicated when dimming them. Then throw in an AFCI and what a headache.

 

[kwired]

It took me a while to find the compatibility list for your 4u's. It was here:
http://www.lutron.com/technicaldocumentlibrary/3682994a_CFL LED Bulb list_Resi Systems.pdf

The MR16 did not show up on that list?

As others have said many electronic devices generate EMI that can upset AFCI's.

Can you try using incandescent lamps temporarily as a test? To determine if the load type is at issue. It is possible that more EMI is generated with an LED load than an Incandescent due to what is referred to as "repetitive inrush current".

You could also try an EMI filter to isolate the loads from the breaker, if nothing else as a test.

Best of luck to you.
CFL's and LED's sure do make things much more complicated when dimming them. Then throw in an AFCI and what a headache.

All the more reason that if they want to push AFCI they need further development to reject undesired tripping. Solid state lighting or lighting ballasts are here to stay for some time.

 

[grasfulls]

do they really see the load?

do they really see the load?

All the more reason that if they want to push AFCI they need further development to reject undesired tripping. Solid state lighting or lighting ballasts are here to stay for some time.

Do they even really see the load? It seems as though they should keep them off of lighting systems.

 

[grasfulls]

SAVANT

SAVANT

hi smartest electricians on planet earth!
i have a case of nuisance tripping of cutler hammer combination type breakers. i have a bunch of them in breaker box but only those serving lutron rpm modules of homeworks system are tripping on completely unpredictable basis. i started to believe in extraterrestrials when trying to determine the cause of tripping. i checked all wiring using afci breaker and gfci load side in lutron panel and they are 100% correct.
with 5 breakers afci comination type (br20caf i believe) i feed 7 rpm 4U's modules in lutron panel. those modules energize mostly lucifer led down lights.
do you have any experience in afci combination type nuisance tripping?
from what i remember there may be factors like: first afci were recommended to be spaced cause the internal electronics generated heat which made them to trip, brush type power tools used to trip afcis.
maybe you can direct me to lighting control or similar forum cause this is not strictly NEC issue apart from the fact installation has to be free of shorts and stuff like that
client wants to move in couple of days.
penny for your thought
thank you in advance

Mine trip on the SAVANT system but only when the utility goes down and powers back up. I am working with CH right now, thanks for the post in the other thread, I wish I had know this was one was already started.

 

[kwired]

Do they even really see the load? It seems as though they should keep them off of lighting systems.

What are you asking about? If the current passes through it why wouldn't it see it? The harmonics, the inductive properties, and any other current distortion always passes through the branch circuit device as well as conductors and other devices in the circuit. AFCI as well as GFCI just happen to be devices that maybe were not designed to accept some of the things introduced by some of the "high tech" items out there. GFCI has less problems because it is looking for simpler problems but occasionally something comes up that maybe creates issues with it.

 

[darekelec]

i found this as helpful

http://www.lutron.com/TechnicalDocumentLibrary/AFCI_FAQ.pdf

 

[grasfulls]

what does teh breaker "see"

what does teh breaker "see"

What are you asking about? If the current passes through it why wouldn't it see it? The harmonics, the inductive properties, and any other current distortion always passes through the branch circuit device as well as conductors and other devices in the circuit. AFCI as well as GFCI just happen to be devices that maybe were not designed to accept some of the things introduced by some of the "high tech" items out there. GFCI has less problems because it is looking for simpler problems but occasionally something comes up that maybe creates issues with it.

I agree the device sees it all, but I think it would be nice if somehow protection could be after the modules so it is only seeing what may cause the end-user harm.

If the controller is, say, a dimming module that uses whatever it does for dimming, I am not asking what they use, does the AFCI see only what a person may see at the load side of that module? It seems to me that the AFCI sees all the "junk" spawned by the module though this poses no threat to anyone. It is one of the reasons Lutron originally came out with the "no more than 1000 watts dimming load", the AFCI was tripping all the time. I think SAVANT lighting is something like 1100 or 1200 but we just stick with the 1000 because we worry about a high-end client having tripping issues when they entertain and have every light in their home on. But I appreciate the pdf referenced above and its opening notation:
"As of September 6th, 2012, a full 2,000 W (16A) of connected dimming load can now be achieved without false tripping using Eaton
?BR, CH, or QB series AFCI breakers. See information beginning on page 4 for more details." Isn't 16 amps 1920 watts?

Has anyone dared try it? It will save a lot of time and money not having to double the modules and circuits.

 

[grasfulls]

Great reference

Great reference

i found this as helpful

http://www.lutron.com/TechnicalDocumentLibrary/AFCI_FAQ.pdf

Thanks! It is great reading!! The last I remember from them was the 1000 watt threshold.

 

[kwired]

I agree the device sees it all, but I think it would be nice if somehow protection could be after the modules so it is only seeing what may cause the end-user harm...

If there is something funky in the current waveform causing the tripping it will not matter where the device is in the circuit because this waveform is at every point in series with whatever is causing the funky to happen.