I will say true, and will also reluctantly say most of those mentioned appliances will likely come with such instructions, and IMO for no good reason other then for them to have an excuse to not honor a warranty if not installed according to instructions.
So do you think OP's disposer is an art 422 appliance or an art 430 motor? If it is a motor and is a true 3/4 hp motor nameplate amps means nothing unless you need to provide overload protection, you default to table 430.248 to find full load current and it says 13.8 amps there. Then comes the issue of if it is not considered a continuous load - exactly what method is used to select conductor ampacity? If we go back to 430.22, we need to actually apply 140 up to maybe 200 percent of rated current to come up with conductor ampacity, unless it is a motor with a rated duty cycle. I can't recall if I have ever seen a "continuous duty" marked on a disposer, but am fairly certain I have never seen any duty cycle ratings - so it still defaults to it being considered continuous duty motor AFAIK. But if it is a 422 appliance instead of a 430 motor - that could change how this is determined, need to dig a little deeper before confirming that though.
As long as both appliances are 10 amps or less it works with code also, get one above 10 amps - real world applications have worked with little or no issue many times, code may not always agree.
You bring up a good point here. It may not even be code from the start. On new installs I have never seen the combined rating of the two go above 20amps, certainly not in the last 10 years with energy efficient dishwasher not going over 6 amps. Rarely are builder disposers anything extravagant to begin with, however I have seen kitchens with some 70s or 80s dishwashers that pull 12 amps with a HO latter replacing the 5 amp builder disposer with a 12 amp Insinkerator (A must have disposer). Violation here no doubt, but again one could argue the NEC doesn't consider possible future changes.The UL Standard has no bearing on NEC requirements unless the pertinent part(s) is(are) included on the product nameplate (such as MCA) or in the product documentation (i.e. its instructions)... or otherwise imposed such as a manufacturers-included or -optional 15A plug.
Good find, exception 3 makes most of this conversation meaningless IMO.
You are mistaking what I'm saying... and what I said was in a generalized context, not topic-item specific. Where the NEC requires or takes a listed item into account, the standard is included by reference... yet where there is a conflict, the NEC supersedes the listing standard (i.e you're installing to the NEC 'standard, not NRTL standard?a safety testing standard; not an installation standard), and this is especially true where the item is not required to be listed.
