mbrooke
Batteries Included
- Location
- United States
- Occupation
- Technician
Without paying for access to UL's proprietary test standard, or reading how UL's test is conducted, I believe the circuit breaker has no AFCI functionality for UL's (AWDT) combo.
Then why would there a limit on cable length?
That limit is set assuming worse case conditions (weak utility source) that will still trip the breaker magnetically.
Therefore, the standard must require the AFCI outlet to reliably trip during test events that occur line-side of AFCI, along the home-run, before the first outlet, before the AFCI outlet.
How will tripping the AFCI de-energize the home run between the panel and first AFCI?
Its no surprise that AFCI's trip on line-side events. I've seen AFCI outlets trip from deteriorating nearby breakers in same panel, separated by several bus stabs and 50ft of Romex.
This stems from AFCIs not being able to recognize and discern ripples in a sign wave. Something like a downed wire miles away can trip them. This is not intended, but a consequence of insufficient computing power.
I believe (AWDT) is the first UL standard that requires AFCI's to reliability demonstrate operation from line-side events, that occur before the AFCI.
Series arc faults are taken care of the 210.12 A 4 a. At least I believe that is the intent to eliminate splices between the panel and first AFCI receptacle.