Solar Facility: 31 Issues Found

The site plan shows a callout '5 STRINGS OF 16 MODULES EA.' for the solar array, but the project specifications table on the same drawing shows 'STRING QUANTITY 10' with 'STRING SIZE 16 MODULES'. With 160 total modules at 16 modules per string, the correct string quantity should be 10 (160÷16=10), not 5 as shown in the plan callout.

Equipment Note 7 requires inverters to be listed to "UL 1704". However, UL 1704 is not the applicable standard for inverters; UL 1741 is the standard for Inverters, Converters, and Controllers. IBC 104.2.1 requires that listings be germane to the provision requiring the listing, and referencing an incorrect or non-existent standard for the equipment violates this requirement.

The drawing provides wind and snow loads but fails to indicate the dead load of the rooftop-mounted photovoltaic panel system. The building code explicitly requires the dead load of the PV system, including the rack support system, to be shown on the construction documents.

The Inverter datasheet specifies a "Max. OCPD Rating" of 125A. The Safety Switch datasheet specifies a switch rating of "200A" without explicitly listing the required fuse size. While the 200A switch frame is required to hold a 125A Class H/R fuse (which physically requires the 101-200A frame), specifying a 200A switch without a specific note to install 125A fuses creates a significant risk that 200A fuses will be installed, which would violate the inverter's UL listing limit of 125A (IBC 2701.1, NFPA 70 110.3(B)).

Detail 2 depicts a "CORD GRIP" installed on the conduit side of a threaded coupler. Cord grips (strain relief fittings) are listed for sealing around flexible cords, not for connecting to rigid conduit or gripping wires inside a conduit. This application violates the listing instructions (IFC 603.1 / NFPA 70 110.3(B)). Furthermore, a single cord grip is shown with multiple "PV CONDUCTORS", which typically requires a specific multi-hole bushing to maintain rating.

E-601 Equipment List specifies PV module model as 'TALESUN TD6172M 450' while E-611 Inverter Schedule specifies 'TD6I72M 450'. The character difference ('1' vs 'I') in the model number indicates different module designations.

E-601 Project Specifications indicates 'STRING QUANTITY 10', but E-611 DC String Schedule only documents 8 strings (1-1 through 1-4 and 2-1 through 2-4). Two strings are missing from the cable schedule documentation.

E-601 Equipment List specifies inverter as 'CPS AMERICA SCA-25KTL-US 208' while E-611 Inverter Schedule shows 'SCA25KTL-DO/US-208'. The 'DO' designation present in E-611 is absent from E-601, and there are hyphen differences suggesting potentially different inverter variants.

The single line diagram on E-601 specifies the PV Fused AC Disconnect (item E) with a 600V 3-phase 3-wire rating. The equipment list on E-601 specifies Eaton model DH324FRK for this disconnect application. However, the product datasheet on E-801 indicates the Eaton DH324FRK has a voltage rating of 240V, which does not meet the 600V rating requirement shown on the single line diagram.

The drawing contains contradictory code references regarding the applicable National Electrical Code (NEC) edition. The 'NOTES AND SPECIFICATIONS' explicitly require compliance with the '2023 ARTICLE 110.21(B)', indicating the project is designed to the 2023 NEC. However, the specific label details reference 'NEC 2017' sections (e.g., 690.13(B), 690.5(C), 705.12(B)(2)(3)(b)).