In my opinion I can't see how one cannot see the different skills involved with commercial and residential.
This may sound overly simplified but, there is more to being an Journeyman Wireman (Commercial work)than electrical and vice versa. A large amount of which is not able to be tested.
Much of commercial work is being a good "mechanic".
So in no particular order, a few examples lol
Larger Service sizes and the implications, bigger wire& cable, bigger material,bigger and more varied tools, switchgear
More panels, differing voltages, transformers, larger variety of lighting and associated hardware
More Building in general, i.e. pipe racks, equipment racks, on and on.
if anyone can add please do
BTW, please, please do not take this as a flame generator...I am not in any way shape or form saying Resi vs commercial is better one way or the other.
Every guy who does a lot of big work knows alot of guys who couldn't wire a 3-way or do a service call, troubleshoot a circuit, etc etc
