48 Photovoltaic Array Installation

Photovoltaic Array Installation is the physical construction process of mounting racking hardware, attaching solar modules, and completing the array-level wiring on a home's roof or ground-mount location, translating the finalized layout design into a securely installed, weatherproofed, and electrically connected array. It represents the most visible and labor-intensive phase of a residential solar project, requiring careful execution of the structural, electrical, and weatherproofing details established during earlier design and planning stages.

Mounting Hardware Installation

Locating and Marking Attachment Points

Installation begins with precisely locating and marking attachment points on the roof surface, aligning them with the underlying structural framing identified during the site survey and consistent with the spacing specified in the structural mounting design, ensuring each fastener will achieve its required holding strength.

Installing Flashing and Fasteners

Crews install weatherproofing flashing at each attachment point before driving the mounting fastener into the structural framing to its specified torque and embedment depth, following the sequence appropriate to the specific roof covering material to correctly integrate the flashing with the surrounding roofing layers.

Racking Assembly

Installing Rails and Mounting Structure

With attachment points secured, crews install the racking rails or mounting structure that will support the modules, aligning the rails according to the finalized layout plan and verifying they are level and properly spaced to accommodate the specified module dimensions and inter-row spacing.

Verifying Structural Integrity

Before proceeding to module installation, crews verify that racking is securely fastened and structurally sound, checking that fasteners are properly torqued and that the assembled racking structure meets the load-bearing requirements established in the structural engineering calculations.

Fastener torque, the rotational force applied during tightening, is specified by the racking manufacturer to achieve the clamping force required for both structural security and, where applicable, proper compression of an integrated waterproofing gasket.

Module Installation and Wiring

Mounting Modules to the Racking

Modules are lifted into position and secured to the racking rails using manufacturer-specified clamps, following the layout plan's specified grid arrangement and orientation, with crews taking care to avoid excessive mechanical stress on module frames during handling and installation.

Making Module Interconnections

As modules are installed, crews connect them according to the designed string configuration, using weatherproof connectors specifically rated for outdoor photovoltaic use, and verifying that polarity is correct at each connection to avoid reverse-current conditions that could damage equipment or create a safety hazard.

Installing Module-Level Electronics

Where the system design incorporates microinverters or power optimizers, these devices are installed and connected at each module during this phase, along with any required grounding connections at the module frame, integrating the module-level electronics into the array's overall electrical and grounding scheme.

Completing the Array Circuit

Routing Conductors to the Combiner or Inverter

Once all modules are installed and interconnected, crews route the resulting string conductors to the array's combiner point or directly to the inverter location, securing conductors along their path to protect them from mechanical damage, ultraviolet degradation, and excessive movement due to wind or thermal expansion.

Initial Electrical Verification

Before proceeding to connect the array to the inverter, crews typically perform initial electrical checks, including verifying string voltage and confirming correct polarity, to catch any wiring errors before the array is connected to downstream equipment and the balance of the system installation continues.