OK, so I have spent the entire weekend upgrading the last remaining old circuit in my 1943 home. It is comprised of 5 switches for overhead fixtures (details below).
Before I changed this all out, all switches were ungrounded (2 conductor only) and were switch loops. What I did was remove every bit of the cloth wire and rewired all switches as a normal switch leg and not a switch loop.
I have the following:
3 switches that are powering a single light fixture. (Meaning, a 1 to 1 switch to fixture leg).
2 switches that are the dual type that are connected to a ceiling fan light combo. 1 switch for fan, 1 for the light.
From the panel, I have a line running to a J-Box that has a joint that provides the supply to 2 of the 5 switches directly and then another line that goes up into the attic to another J-Box that then provides the joints for the remaining 3 switches.
14/2 (except for the rooms where the ceiling fans are, where I am providing the switch leg with a 14/3 of course).
All switches have the common hot on one side and the fixture hot on the other. Neutrals are combined in the boxes and connected at the fixtures. Grounds are all bonded to the metal boxes and fixture boxes as well as connected together as required (except one that is in a plastic old work box due to size restraints).
Everything in the circuit is straightforward. I am super careful pulling wire and inspecting to ensure nothing is nicked. I am always pretty OCD about my electrical work and everything is connected with appropriate size wire nuts (though I do use push in connectors for my grounds in some cases, but never for hots or neutrals).
In the LC panel, I am using an Eaton AFCI/GFCI combined BRN115A1CS. 15a, single pole. I have never used one of these before (never used a GFCI nor an AFCI breaker to be perfectly honest, but figured now is as good a time as any to start).
I can turn the breaker on and it stays on. Tests appropriately. However, whenever I flip on ANY of these switches, it trips immediately. LED code is 5 blinks which is Ground Fault/ or Grounded Neutral.
"Current has found an alternative path to ground, or the neutral and ground are in contact downstream of the breaker"
I am baffled at this point since I surely don't think anything I wired would be in this state (seriously, I am VERY meticulous).
Now, here is the big question that may be the simple answer and shows my ignorance of requirements for GFCI breakers - to use a GFCI breaker, does the neutral and ground have to be on separate bus bars? Up until now, in my main (and since it is my main), I have bonded neutral and ground bus bars. This seems, though, that this would be upstream, correct?
Of course, I will start to go back through all of my switches and fixtures, but is there anything that I have stated that would indicate a problem right off the bat? Thanks!