Article 685

Integrated Electrical Systems

Part I. General

685.1 Scope. This article covers integrated electrical systems, other than unit equipment, in which orderly shutdown is necessary to ensure safe operation. An integrated electrical system as used in this article is a unitized segment of an industrial wiring system where all of the following conditions are met:

  1. An orderly shutdown is required to minimize personnel hazard and equipment damage.
  2. The conditions of maintenance and supervision ensure that qualified persons service the system. The name(s) of the qualified person(s) shall be kept in a permanent record at the office of the establishment in charge of the completed installation.A person designated as a qualified person shall possess the skills and knowledge related to the construction and operation of the electrical equipment and installation and shall have received documented safety training on the hazards involved. Documentation of their qualifica‐ tions shall be on file with the office of the establishment in charge of the completed installation.
  3. Effective safeguards acceptable to the authority having jurisdiction are established and maintained.

685.3 Application of Other Articles. The articles/sections in Table 685.3 apply to particular cases of installation of conduc‐ tors and equipment, where there are orderly shutdown require‐ ments that are in addition to those of this article or are modifications of them.

Part II. Orderly Shutdown

685.10 Location of Overcurrent Devices in or on Premises. Location of overcurrent devices that are critical to integrated electrical systems shall be permitted to be accessible, with mounting heights permitted to ensure security from operation by unqualified personnel.

685.12 Direct-Current System Grounding. Two-wire dc circuits shall be permitted to be ungrounded.

Table 685.3 Application of Other Articles


Conductor/Equipment Section





converter (optional

PV or DC-to-DC converter output circuit

More than one building or

other structure

Ground-fault protection of equipment

225, Part II

230.95, Exception


PV source

Protection of conductors 240.4

Electrical system coordination 240.12


Ground-fault protection of equipment

Grounding ac systems of 50 volts to less than 1000 volts






Equipment protection 427.22

Orderly shutdown 430.44

Disconnection 430.75, Exception Nos. 1 and 2


Disconnecting means in sight from controller

Energy from more than one source

430.102(A), Exception No. 2 430.113, Exception Nos. 1 and 2

Array, subarray, or PV power source

Disconnecting means 645.10, Exception

Uninterruptible power supplies (UPS)



Point of connection 705.12

685.14 Ungrounded Control Circuits. Where operational continuity is required, control circuits of 150 volts or less from separately derived systems shall be permitted to be ungroun‐ ded.

  1. These diagrams are intended to be a means of identification for PV power source components, circuits, and connections that make up the PV power source.
  2. Custom PV power source designs occur, and some components are optional.

FIGURE 690.1(a) Identification of PV Power Source Components.