A: A White Paper published by Bill Brooks P.E. of Brooks Engineering, Vacaville, CA (brooksolar.com) carefully examines all aspects of Cable Management in Solar PV Arrays. Click here to read this important White Paper, updated March 20, 2021.
A: “A common thread in the installation of electrical systems is that the work be done in a neat and workmanlike manner [NEC 110.12] and that conductors are not exposed to physical damage [NEC 300.4]. Physical damage is not specifically defined in the NEC or in ANSI/NECA 1-2010; however, it is generally understood as being self-defined. "In a large PV power plant, the perimeter fencing and security system that keeps unqualified people out of the facility is sufficient to prevent physical [...]
A: NEC Article 690.31(C)(2) addresses support and securement requirements which apply to Cable Tray and Cable Rings and Saddles. A maximum spacing of 12” should be used for cable sizes less than 1/0 AWG. A maximum spacing of 18” should be used for cable sizes greater than 1/0 AWG. The same article requires securement intervals no larger than 4.5 feet for USE-2 and PV Wire. - Bill Brooks, P.E., White Paper: Cable Management in Solar PV Arrays, Pages 5-6, Jan. 16, [...]
A: There is a significant change in the 2014 NEC that disallows AC and DC conductors to be installed together in the same raceway or enclosure unless they are separated by a partition. The CAB Cable Ring system allows for two different lengths of Cable Rings to be installed from the same messenger wire. This effectively creates the separation between the AC and DC cables that is necessary. - Bill Brooks, P.E., White Paper: Cable Management in Solar PV Arrays, Page [...]
A: “As cables are bundled together, the inner conductors are not in free air and their ampacity is similar to conductors in a raceway. Therefore, to be conservative, a cable bundle of three cables should be subject to the ampacity limitations of Table 310.15(B)(16) which is used for up to three conductors in a raceway. Since outdoor ambient design temperatures are generally above 30 degrees C for most of the United States, an additional correction factor for temperature should be applied [...]
A: ANSI/NECA 1-2010 standard (q) states: When using cable ties, do not over tighten, to ensure the cable tie does not cut the conductor’s outer jacket. Cable ties shall not be used to support raceways or cables. “It is the recommendation of this standard that cable ties not be used to support cables. It is common to see cable ties used in PV installation as the sole method of support. While it is not specifically disallowed in the NEC, this industry [...]
A: CAB Cable Rings and Saddles fall under the definition of “fitting” in Article 100 of the NEC. A fitting is an accessory such as a locknut, bushing or other part of a wiring system that is intended primarily to perform a mechanical rather than an electrical function. In his White Paper, Bill Brooks expands on this subject: “Some AHJs may request that exposed metal rings and saddles be evaluated for bonding, but this is not well substantiated in the NEC, [...]
Frequently Asked Questions regarding Use of CAB Cable Rings and Saddles For Solar PV Arrays Q: How does NEC 330.4 Protection Against Physical Damage apply to CAB Cable Rings and Saddles? A: “A common thread in the installation of electrical systems is that the work be done in a neat and workmanlike manner [NEC 110.12] and that conductors are not exposed to physical damage [NEC 300.4]. Physical damage is not specifically defined in the NEC or in ANSI/NECA 1-2010; however, it [...]