article 409 does not cover distribution panels..
This is what is says in NEC Handbook about section 409
I. General
409.1 Scope.
This article covers industrial control panels intended for general use and operating at 600 volts or less.
FPN: UL 508A is a safety standard for industrial control panels.
Article 409 was introduced in the 2005 NEC and provides installation and construction requirements for industrial control panels. These field- and factory-assembled control panels are used for the control and operation of a multitude of processes, from a sewerage pump station to an industrial process line. Similar in function to motor control centers in some regards, control panels also contain control, overcurrent protection, and power distribution equipment for operation of industrial heating processes, robotics, spray painting and powder coating lines, and countless other processes.
409.2 Definitions.
Section 409.2 provides a definition for industrial control panel that is compatible with industry product standards such as UL 508A, Industrial Control Panels. For the 2008 Code, the definition of control circuit was added and the definition of industrial control panel was revised to include panels with two or more control components.