Posting this for a friend since some of the members here do lighting.

He installed the following equipment and sometimes when the lights are turned on the ArcFault trips. He has contacted Lutron and the are sending a different dimmer. That dimmer might not work correctly with the Juno lights.

Siemens
QA120AFC
Combination TT/PE ArcFault
Circuit Interrupter

Lutron
Caseta PD6
APP Controlled Dimmer

Juno
4RLA63 2700K
LED Recessed Light Trim

Any suggestions or can you point me to a message board or someone who might know the answer.

Thanks

What is the quantity of the Juno lights on that one dimmer?

I will check with the electrician and report back.

David asks a good question. We'll probably need to know many more details to figure out the answer to this problem.

You/your friend may need to (and probably should have) contacted the manufacturers of each of these items for recommendations of products to use and to avoid in this setup.

Could also be a breaker issue. We (as an electrical contractor) have seen very sensitive AFCI breakers (typically when combined with GFCI protection). I would suggest installing a standard breaker and add a faceless AFCI receptacle [Link: leviton.com] at the panel. This will still meet the code requirement but bypass the sensitive breaker.

We moved away from Siemens do to their Arc Fault issues. There are so many different generations of breakers that it's tough to say what version they have and if replacing it will fix the problem. Basically each generation has improved their arc signature recognition but it still never solves every problem. David asks the question about the number of lights being dimmed on that particular circuit (not just the switch) because there is a max wattage per breaker (typically 1000 watts). This number is tough to reach with LED but super easy with incandescent lighting.

Long story short, it's the breaker and you may not be able to fix the problem by replacing the breaker unless it's an older gen arc fault breaker. The only fix is illegally pulling out the arc fault breaker and installing a standard breaker. Which we all know will work fine. The question is, do you want to take the liability on if there is a fire....

Do AFCI still trip easily when a vacuum cleaner is used on those circuits and is the requirement to replace as soon as they trip?

This is why I suggested adding the faceless AFCI at the panel. This still conforms to Code and allows to use a standard breaker. We do this all the time on Renovation projects or areas where we run into nuisance trips as stated. For some reason the Leviton AFCI devices are less sensitive than breakers.

I would first look at the age of the vacuum. If it's an older unit my guess it uses an AC motor causing the ARC when it starts (same goes for cheaper/older treadmills and other workout equipment). If its a newer vacuum try it on another circuit and see if it trips that breaker as well. If it happens on multiple circuits my guess is its a vacuum issue not a breaker issue. If only happens on one circuit may be an over current issue or a sensitive breaker. I would not replace the breaker right away until investigating more.

We use Schneider electric panels and breakers and have never had a customer complain that their vacuum is tripping breakers.

One issue we did come across was Central Vacuums tripping AFCI breakers. Performing the diagnostic test on the breaker it was tripping on over current not ARC. We installed a standard (non-ARC) High inrush breaker with the faceless AFCI device and the issue stopped.

One other issue was when using a combination AFCI/GFCI breaker. These are a lot more sensitive and with some kitchen appliances plugged in (no real load just lights and clocks), the breaker would trip. We could not determine what appliance was actually causing this so added a GFCI receptacle and replaced the breaker with an AFCI only breaker which fixed the issue.

are you saying the inline arc device is less sensitive than arc fault breaker?

Thanks for all of the responses, I will pass them along to the electrician.

He is in touch with Lutron and they are aware of the problem but do not have a fix yet.

I will post back the solution once I find out from the electrician. Hopefully it will help someone else out.

It has to do with the inrush currents from LED drivers. Incandescents don't have this problem.

[Link: unvlt.com]

So arc fault breakers weren't tripping prior to LED drivers? I believe the UL listing on arc fault breakers state they need to support at least 1000 watts of dimmed tungsten lighting load. Tungsten lighting loads typically have a higher in-rush than standard incandescent loads and are still considered incandescent.

We've seen plenty of problems with dimming and non-LED arc fault circuits. Including having Siemens engineers out to our job site to determine what's going on. They found random things on other breakers (same phase) causing an arc fault breaker to trip.

The overall point is that arc fault circuits can be tricky. The age of the breaker can and the manufacturer can play a huge role into the issues.

yep

this is true, but most folks do not understand that LED has a large in rush. in a lot if not all cases more than an equal amount of traditional incandescent loads