Article 690 SOLAR PHOTVOLATIC SYSTEM

Bipolar photovoltaic array (90.2)

A PV array that has two outputs, each having opposite polarity to a common reference point or center tap.

Alternating-current PV module (90.2)

A PV module unit consisting of solar cells and an integral micro-inverter that changes DC power to AC power when exposed to sunlight, and that is listed as an AC module.

Monopole sub array (90.2)

A PV sub array that has two conductors in the output circuit: one positive (+) and one negative (−). Two monopole PV sub arrays are used to form a bipolar PV array. Every module is monopole (two wires).

Interactive system (90.2)

A PV system that operates in parallel (interactive) with electrical utility power (or other power source, e.g., generator or wind system) through a utility-interactive inverter. Listed utility-interactive inverters automatically stop exporting AC power upon loss of the utility (or other source) power, and automatically resume exporting AC power to the utility source once it's been restored for at least five minutes [705.40 Exception].

Stand-alone system (90.2)

A PV system that supplies power without an interconnection to another electric power source. Is an off-the-grid electricity distribution system.

Module (90.2)

A PV unit designed to generate DC power when exposed to sunlight. PV modules use sunlight to make direct current (DC) electricity by using light (photons) to move electrons in a circuit. This is known as the "photovoltaic effect."

DC-to-DC converter (90.2)

A device (installed in the PV source circuit or PV output circuit) that provides output DC voltage and current at a higher or lower value than the input DC voltage and current. These components are intended to maximize the output of independent modules and reduce losses arising from variances between module outputs. They're directly wired to each module and bolted to the module frame (or PV rack).

Electrical Production and Distribution Network (90.2)

A power production, distribution, and utilization system, such as a utility system and connected loads, that is extended to and not controlled by the photovoltaic power systems.

Array (90.2)

An electrical, mechanically integrated assembly of PV modules or panels with a support structure and foundation, tracker, and other components that form a DC power-producing unit.

Multimode inverter. (90.2)

An inverter that has the capabilities of both stand-alone and utility-interactive systems (see Multimode Inverters sidebar).

PV output circuit (90.2)

Circuit conductors between the DC combiner and the DC input terminals of the inverter or DC disconnect (Fig. 3).

PV power source. (90.2)

One or more arrays of PV modules that generate DC voltage and current power.

Building integrated photovoltaic. (90.2)

PV cells, devices, modules, or modular materials designed to integrate into the outer surface or structure of a building (e.g., roof shingles that are the actual modules).

Inverter (90.2)

Electrical equipment that changes AC power from the PV system to grid-interactive AC power. Inverters change direct current produced by the PV modules or batteries into alternating current. Grid-tied inverters synchronize the AC output current with the utility's AC frequency, thus allowing the PV system to transfer unused PV system current to the utility grid. Battery-based inverters for standalone systems often include a charge controller, which is capable of charging a battery bank from a generator during cloudy weather.

Charge controller (90.2)

Equipment that controls dc voltage or dc current, or both, used to charge a battery.

Inverter (2). (90.2)

Equipment that is used to change the voltage level or waveform, or both, of electrical energy. Also known as PCU or PCS, is a device that changes dc inputs to an ac output. Inverters may also function as battery charges that uses alternating current from another source and convert it into direct current for charging batteries

Inverter input circuit (90.2)

The DC conductors between the battery and inverter of stand-alone systems or PV output circuits and an inverter for a utility-interactive system.

Solar cell (90.2)

The basic building block of PV modules, these generate DC power when exposed to sunlight.

PV source circuit (90.2)

The circuit conductors between the PV modules and the terminals of the DC combiner, or the inverter DC input terminals if no DC combiner is used. PV source circuits are often called "strings."

PV system voltage. (90.2)

The direct current (DC) voltage of any PV source or PV output circuit. For multiwire installations, the PV system voltage is the highest voltage between any two DC conductors.

Article 690

applies to PV electrical energy systems, array circuits, inverter and charge controllers for such systems which be interactive with other electrical power sources or stand-alone, with or without energy storage.