PowerPoint ® Presentation Chapter 11 Electrical Integration National Electrical Code Voltage and Current Requirements Conductors and Wiring Methods

PowerPoint® PresentationPowerPoint® Presentation

Chapter 11Chapter 11Electrical IntegrationElectrical Integration

National Electrical Code • Voltage and Current Requirements •

Conductors and Wiring Methods • Overcurrent Protection • Disconnects •

Grounding • Battery Systems

National Electrical Code • Voltage and Current Requirements •

Conductors and Wiring Methods • Overcurrent Protection • Disconnects •

Grounding • Battery Systems

Chapter 11 — Electrical IntegrationChapter 11 — Electrical Integration

Many articles in the NEC® are applicable to the electrical integration of a PV system, particularly Article 690.

Many articles in the NEC® are applicable to the electrical integration of a PV system, particularly Article 690.


The NEC® defines the various circuits and components in PV systems and specifies their requirements.

The NEC® defines the various circuits and components in PV systems and specifies their requirements.


Array open-circuit voltage is corrected for low temperatures to yield the maximum possible PV circuit voltage.

Array open-circuit voltage is corrected for low temperatures to yield the maximum possible PV circuit voltage.


Conductor sizes typically used in PV systems range from 18 AWG to 4/0 AWG. Conductors may be solid or stranded. Larger conductors have lower resistance for a given length.

Conductor sizes typically used in PV systems range from 18 AWG to 4/0 AWG. Conductors may be solid or stranded. Larger conductors have lower resistance for a given length.


Ampacity is the current-carrying capacity of a conductor, which depends on the conductor’s type, size, and application.

Ampacity is the current-carrying capacity of a conductor, which depends on the conductor’s type, size, and application.


Conductor ampacity must be derated for high operating temperatures.

Conductor ampacity must be derated for high operating temperatures.


For conduits installed on rooftops, an extra temperature adder is needed to account for the extreme ambient temperatures of the environment. The adjusted ambient temperature is then used to determine the temperature-based ampacity correction factor.

For conduits installed on rooftops, an extra temperature adder is needed to account for the extreme ambient temperatures of the environment. The adjusted ambient temperature is then used to determine the temperature-based ampacity correction factor.


Conductor ampacity must be derated for more than three current-carrying conductors together in a conduit or cable.

Conductor ampacity must be derated for more than three current-carrying conductors together in a conduit or cable.


Information printed on the outer jacket of a conductor includes size, insulation type, environmental exposure, temperature ratings, and listing approval.

Information printed on the outer jacket of a conductor includes size, insulation type, environmental exposure, temperature ratings, and listing approval.


Conductors in different parts of a PV system have different application requirements.Conductors in different parts of a PV system have different application requirements.


Source-circuit conductors for PV module interconnections within the PV array are permitted to be exposed if the conductor insulation has the required environmental resistances.

Source-circuit conductors for PV module interconnections within the PV array are permitted to be exposed if the conductor insulation has the required environmental resistances.


Modules are typically connected together in PV source circuits with external, exposed connectors.

Modules are typically connected together in PV source circuits with external, exposed connectors.


When tightened and torqued properly, screw terminals produce secure and low-resistance connections.

When tightened and torqued properly, screw terminals produce secure and low-resistance connections.


Lugs are crimped conductor terminations in ring, fork, spade, or pin shapes.Lugs are crimped conductor terminations in ring, fork, spade, or pin shapes.


Splicing devices, such as screw terminal blocks, are used in PV systems to connect or extend conductors or to parallel array source circuits. This type of terminal would not be used for a tap.

Splicing devices, such as screw terminal blocks, are used in PV systems to connect or extend conductors or to parallel array source circuits. This type of terminal would not be used for a tap.


Several NEMA plug-and-receptacle configurations are acceptable for use with DC branch circuits.

Several NEMA plug-and-receptacle configurations are acceptable for use with DC branch circuits.


Module junction boxes contain and protect the module terminal connections and diodes in the source circuit. Some are field-accessible.

Module junction boxes contain and protect the module terminal connections and diodes in the source circuit. Some are field-accessible.


Multiple PV source circuits are combined into the PV output circuit within the combiner box.

Multiple PV source circuits are combined into the PV output circuit within the combiner box.


Blocking diodes may be used in the source circuit whereas bypass diodes are installed within a module or its junction box. These diodes help preserve system output and protect PV modules from damage.

Blocking diodes may be used in the source circuit whereas bypass diodes are installed within a module or its junction box. These diodes help preserve system output and protect PV modules from damage.


Bypass diodes may be installed in the module junction box.

Bypass diodes may be installed in the module junction box.


A number of different types of conduit may be used in PV systems if they have the appropriate ratings.

A number of different types of conduit may be used in PV systems if they have the appropriate ratings.


Current-limiting overcurrent protection devices open a short circuit before current reaches its highest value.

Current-limiting overcurrent protection devices open a short circuit before current reaches its highest value.


Overcurrent protection devices include fuses and circuit breakers of various types and ratings.

Overcurrent protection devices include fuses and circuit breakers of various types and ratings.


Array source circuits are fused individually within the source-circuit combiner box.

Array source circuits are fused individually within the source-circuit combiner box.


Overcurrent protection for the inverter output circuit depends on the system type. Overcurrent protection and disconnecting means can be accomplished by using circuit breakers or fused disconnects.

Overcurrent protection for the inverter output circuit depends on the system type. Overcurrent protection and disconnecting means can be accomplished by using circuit breakers or fused disconnects.


Connecting a 120 V inverter to a 120/240 V panelboard with multiwire branch circuits may cause dangerous overloading in the grounded (neutral) branch circuit conductor and must be avoided.

Connecting a 120 V inverter to a 120/240 V panelboard with multiwire branch circuits may cause dangerous overloading in the grounded (neutral) branch circuit conductor and must be avoided.


The array disconnect opens all current-carrying conductors in the PV output circuit.

The array disconnect opens all current-carrying conductors in the PV output circuit.


The AC disconnect of an interactive PV system may be located close to the main utility service disconnect, which can satisfy utility requirements for an external, visible-break, and lockable PV system disconnect.

The AC disconnect of an interactive PV system may be located close to the main utility service disconnect, which can satisfy utility requirements for an external, visible-break, and lockable PV system disconnect.


Switches or circuit breakers are required to isolate and disconnect all major components in a PV system from all ungrounded conductors of all power sources.

Switches or circuit breakers are required to isolate and disconnect all major components in a PV system from all ungrounded conductors of all power sources.


The DC grounding system and the AC grounding system must be connected together with a bonding conductor. The array may also require a separate grounding electrode system.

The DC grounding system and the AC grounding system must be connected together with a bonding conductor. The array may also require a separate grounding electrode system.


Some inverters include fuses as array ground-fault protection in their DC input circuits.Some inverters include fuses as array ground-fault protection in their DC input circuits.


Circuit breakers can be used for array ground-fault protection when the inverter does not already provide this protection.

Circuit breakers can be used for array ground-fault protection when the inverter does not already provide this protection.


A ground-fault circuit interrupter (GFCI) senses differences between the current in the grounded and ungrounded conductors, indicating a ground fault, and opens the circuit in response.

A ground-fault circuit interrupter (GFCI) senses differences between the current in the grounded and ungrounded conductors, indicating a ground fault, and opens the circuit in response.


Modules should be connected to each other and the mounting structure with grounding conductors to ensure a continuous grounding connection.

Modules should be connected to each other and the mounting structure with grounding conductors to ensure a continuous grounding connection.


Equipment grounding conductors are sized based on the rating of the overcurrent protection device in the circuit.

Equipment grounding conductors are sized based on the rating of the overcurrent protection device in the circuit.


Lightning protection is especially important in the southeastern states, which have the highest lightning-strike density in the United States.

Lightning protection is especially important in the southeastern states, which have the highest lightning-strike density in the United States.


A lightning protection system includes a network of air terminals, a grounding electrode (down) conductor, and a set of grounding electrodes.

A lightning protection system includes a network of air terminals, a grounding electrode (down) conductor, and a set of grounding electrodes.


Surge arrestors may be incorporated into equipment or can be installed on circuits as separate devices.

Surge arrestors may be incorporated into equipment or can be installed on circuits as separate devices.


Connectors may be used for disconnecting high-voltage battery banks into lower voltage segments for servicing.

Connectors may be used for disconnecting high-voltage battery banks into lower voltage segments for servicing.

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PowerPoint ® Presentation Chapter 11 Electrical Integration National Electrical Code Voltage and Current Requirements Conductors and Wiring Methods