On Tue, 6 Oct 2015 10:58:16 -0700 (PDT), trader_4
wrote:

My undestanding of "dedicated" circuits is that it can't be possible
to plug anything *else* into the circuit alongside the "dedicated"
appliance.

E.g., our dishwasher, refrigerator, furnace, etc. all have "single
outlet" receptacles.

They can do that, but AFAIK, there is no NEC code requirement that
the fridge and DW be on dedicated circuits or that they utilize
single receptacles.

Aa far as the furnace being on a cord plugged into a receptacle,
that is a NEC violation, unless you have some furnace that came
with a cord and plug, which I highly doubt exists and the furnace
requires it for maintenance. Some inspectors in some areas are
OK with it though.

The guys I know are about 50:50 with these things being "cord and
plug". The ones who are OK with it still want it done right. That
means no romex jammed into a plug, use a real hard service cord and
use the proper cord connectors, not romex clamps..

I do understand that if you are keeping your house from freezing with
a portable generator, it is better to use cords than to be back
feeding the dryer receptacle with a suicide plug.