If you have more than 6 switches (breakers) in the subpanel in the shop,

it

needs to have a main disconnect. If it has six or fewer switches, you can
get by without a main disconnect.


Can you document that? My subpanel has room for 16 breakers (I am using 7
of them) but nowhere for a main disconnect.
I don't know why you would even want a main disconnect; doesn't the breaker
in main panel do that?


Here are the sections of the US NEC that require you to have a building
disconnecting means. The usual way to accomplish that in a main lug
only panel is to install a double pole breaker with a kit that holds it
into the panel so that it cannot be readily removed. The feeder
conductors are than connected to the terminals of that breaker which
feeds the power into the buss bars via the breakers push on contacts.
--
Tom H

225.31 Disconnecting Means.
Means shall be provided for disconnecting all ungrounded conductors that
supply or pass through the building or structure.

225.33 Maximum Number of Disconnects.
(A) General. The disconnecting means for each supply permitted by 225.30
shall consist of not more than six switches or six circuit breakers
mounted in a single enclosure, in a group of separate enclosures, or in
or on a switchboard. There shall be no more than six disconnects per
supply grouped in any one location.
Exception: For the purposes of this section, disconnecting means used
solely for the control circuit of the ground-fault protection system, or
the control circuit of the power-operated supply disconnecting means,
installed as part of the listed equipment, shall not be considered a
supply disconnecting means.
(B) Single-Pole Units. Two or three single-pole switches or breakers
capable of individual operation shall be permitted on multiwire
circuits, one pole for each ungrounded conductor, as one multipole
disconnect, provided they are equipped with handle ties or a master
handle to disconnect all ungrounded conductors with no more than six
operations of the hand.