Where in the code does it explain about using main lug panels. I'm going about 220ft. from a main breaker panel, feeding a 100 amp panel. Normally I would use a main breaker panel anyway, but so far I don't seem to find one that fits my need. thanks
I don't think it does. I always like using a panel with a Main because it reduces the temptation to work it hot when someone doesn't want to walk to the feeder breaker and turn it off...but I don't think there's a requirement for a main.
That does not really address the hot bus but I suppose there are still hot components in a panel with a main. (Unless you are in Canada where they have a cover over the main lugs from what I understand)
I understand that it is not a huge hazard. I suppose I was just saying identifying where it comes from is a good idea for that time when you are working on something more complicated than a branch circuit.