254.146(D) Isolated Ground Receptacles. Where installed for the
reduction of electrical noise (electromagnetic interference)
on the grounding circuit, a receptacle in which the ground-
ing terminal is purposely insulated from the receptacle
mounting means shall be permitted. The receptacle ground-
ing terminal shall be connected to an insulated equipment
grounding conductor run with the circuit conductors. This
equipment grounding conductor shall be permitted to pass
through one or more panelboards without a connection to
the panelboard grounding terminal bar as permitted in
408.40, Exception, so as to terminate within the same
building or structure directly at an equipment grounding
conductor terminal of the applicable derived system or ser-
vice. Where installed in accordance with the provisions of
this section, this equipment grounding conductor shall also
be permitted to pass through boxes, wireways, or other
enclosures without being connected to such enclosures.