NEC Section 550.51 covers service equipment related to mobile homes and states the following:

Manufactured home service equipment shall be permitted in or on manufactured homes if all of the following conditions are met:

(1) The manufacturer shall indicate, in its written installation instructions, that the home is to be secured in place by an anchoring system or installed on and secured to a permanent foundation.

(2) The installation of the service shall comply with Article 230 Parts I through VII.

(3) Means shall be provided for the connection of a grounding electrode conductor to the service equipment and routing it outside the structure.

(4) Bonding and grounding of the service shall comply with Article 250 Parts I through V.

(5) The manufacturer shall include, in its written installation instructions, one method of grounding the service equipment at the installation site.

(6) The minimum size grounding electrode conductor shall be specified in the instructions.

(7) A warning label, meeting the requirements in 110.21(B) and stating the following, shall be mounted on or adjacent to the service equipment:

WARNING

DO NOT PROVIDE ELECTRICAL POWER

UNTIL THE GROUNDING ELECTRODE(S)

IS INSTALLED AND CONNECTED

(SEE INSTALLATION INSTRUCTIONS).

Where the service equipment is not installed in or on the unit, the installation shall comply with the other provisions of this section.

North Dakota has amended this code section with additional requirements. Refer to the Laws, Rules and Wiring Standards of North Dakota for additional rules pertaining to mobile home parks.