2.1.4 Electrical Balance-of-System (BOS) Hardware

2.1.4.a. Electrical Service Equipment                

Best Practices: The Series - #7: Photovoltaic Labs - 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           

Best Practices: The Series - #7: Photovoltaic Labs - 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  


Best Practices: The Series - #7: Photovoltaic Labs - 2.1.4.c. Fuses and Breakers
  • 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

Best Practices: The Series - #7: Photovoltaic Labs - 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.

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