2.1.4 Electrical Balance-of-System (BOS) Hardware
Links of manufacturers and/or suppliers for this section: PDF
2.1.4.a. Electrical Service Equipment
Specifications: At least two residential service and distribution panel mockups for interconnecting PV Systems (200A and 100A main panels, with main breakers, suggested as a minimum.
Suggested Quantity: Minimum of 2 (one 200A and one 100A)
Importance Rating: Essential.
Comments: This equipment is essential for demonstrating load and supply side interconnections.
2.1.4.b. PV Array Combiner Boxes
Specifications: PV array source circuit combiner boxes: compact, disconnecting and standard homerun types. (Disconnecting, Arc-fault detecting and interrupting models are 2011 NEC code requirements. Recommended models include Copper Bussman BCBC-04-10P, BCBD150-12-15R and BCBS-12-30F.)
Suggested Quantity: One per system.
Importance Rating: Essential.
Comments: The boxes are a key component for combining array source circuits.
2.1.4.c. Fuses and Breakers
Specifications:
- DC-rated breakers for low-voltage battery based systems
- DC rated fuses and touch-safe fuse holders for combiner boxes
- Assortment of spare DC-rated 600V supplementary fuses for combiner boxes and inverter GFDI circuits (600 VDC: KLM-1, KLM-10, KLM-15; Solar PV Fuses 1000 VDC: 1, 10, and 15 amp)
Suggested Quantity: 4 – 6 of each
Importance Rating: Essential (for combiner boxes and battery based systems)
Comments: Fuses and Breakers must show the required DC-rated, over-current disconnecting means to meet NEC requirements.
2.1.4.d. Miscellaneous Electrical BOS Hardware
Specifications: Other related service equipment, combination meter/service entrance devices, metering equipment, and tapping splices.
Suggested Quantity: As needed.
Importance Rating: Essential (as needed)
Comments: The hardware is used to demonstrate alternative PV interconnection methods.