Welcome. My name is XXXXX XXXXX would be glad to assist.
First, if the home was built with the Arc Faults at the time, please leave it, you cannot remove it and change to a standard breaker.
The grounds not being connected would not create the issue, but they certainly should be connected for safety
To pass inspection they are supposed be connected to switches
On the arc fault tripping, any loose connection can create the problem. They are very sensitive and only a few milliamps of difference on the wires will trip one.
Arc Faults are similar to the GFCI except they look for arcing in the circuit at all connection points and sense it, then trip to protect from overheating and arcing fires.
So, just one simple barely loose wire on a screw can trip the arc fault.
I would check all connections on the switches, make sure they used the side screws and did not plug the wires in the rear with the "quick" connections. If they did, I would move them to the side screws for tightness.
Next make a directory of everything on that one circuit to be sure that possibly something like a radio is not plugged into a receptacle on the Arc Fault. Clocks, radios, lamps etc can cause the issue randomly.
If you know all the receptacles on the arc fault, you can eliminate anything plugged in as the problem by simple elimination one at a time.
As it was doing it prior to anything being plugged into the office. It kind of got narrowed down to bathroom lights and fan- 1 x200w halogen, 2 x 9watt LED, 2x 150 watt 39" incandescent, 1 fan with cfl
I would want to check the connections on the switches if you did not have anything plugged into a receptacle.
A simple loose wire will trip an arc fault, that is what they were designed for "arcing" in the wire circuitry.
If they used the stab in connections especially, those are prone to problems with arc fault circuits
Yes, they used the stab/quick connections - Thanks for the advice
So many do that today and its an issue with the arc faults and many GFCI's too. The old days didnt have the fancy circuitry and electronics as we do today, but some still use the short cuts.
I would suggest to connect grounds on all the switches while doing any changes, dont see how it got by the inspectors when final inspection was performed.
Usually we find just putting wires on the side screws eliminates arc fault issues. Many times it is a radio or lamp with loose bulb. Check all bulbs for tightness and the bath fan switch for sure as the fan motor has internal arcing to an extent, so a loose connection is even more critical on it.
Just let me know if I can provide any other information for the situation, thanks