PV Cables UL Listed for 600VDC/1000VDC.
PV cables are halogen free , do not spread fire and they are characterized by reduced emission of opaque smoke. Given their fireproofing and the low corrosiveness of the gases emanated PV cables are the best fit for solar installations. PV cables offer an adequate protection against attacks by rodents, and resist vey well to mechanical aggressions. PV cables are intended for use in outdoor and indoor applications. All materials involved in cable structure are flame retardant (FR), halogen free (HF), low smoke (LS) and they provide resistance in case of fire. All PV cables are compliant to: UL 4703, for cables rated to 600V, at -40°C up to 90°C and they are NEC 2008 Article 690 code compliant. PV cables are coming as single jacketed cable or double jacketed (double isolation) type of cables.
As PV cables we refer to wire or cable types specified in the National Electrical Code® (NEC) for PV installations and those are either service entrance cable type or photovoltaic (PV) wire used for interconnections within the photovoltaic array.
As a general remark when it comes to the wire and cable for PV module interconnections, only those wire or cable types specified in the National Electrical Code® (NEC) can be used and sold in the United State.
PV installations are using both PV Wire and USE-2 Wire. Between this type of cables used as service entry cable for solar arrays the difference consist in maximum voltage they can be loaded with, ( PV Wire are servicing 1000V and 2000V arrays), temperature range under they can work with minimum constraint (PV Wire range is 90ºC wet rating and up to 150ºC dry rating), general usage: PV Wire is dedicated for interconnecting PV modules, USE-2 Wire is designated as underground service entrance cable typically for connecting to the terminals of service equipment.
North American requirements for PV Cables:-
As a general requirement all PV cables must be compliant with Sec. 690.31(B) of the 2008 NEC® if either they are single conductor type of wire or multi strand wires. They must sustain elevate working temperature conditions as 90ºC or above for wet environment, the insulation of the module conductors is required to be sunlight resistant (UV resistant) and provide enough mechanical endurance to be exposed to outdoor locations.
For investigating the compliance to the standard code we use UL 854 Service-Entrance Cables and UL 4703 Outline for Photovoltaic Wire, respectively.
PV - Wire and USE - 2 Wire are both used in PV wiring applications but between them is a remarkable difference. To compare both type of wires he have to refer to general usage, wire structure, testing requirements.
PV-Wire is dedicated for interconnecting PV modules. USE-2 Wire is recommended as underground service entrance cable typically for connecting to service equipment.
Environment specific, PV Wire it is rated between 90ºC wet up to 150ºC dry; USE-2 Wire it is rated maximum 90ºC dry.
Voltage serviced by the wire, USE-2 Wire it is used in systems rated for 600V. PV Wire it is used for both 600V rated system and 1000V rated one. On the PV market the request for PV Wire rated for 2000V it is present with cable manufacturer delivering reels in this voltage range.
Per NEC array grounded systems: USE-2 Wire it is used in grounded PV arrays, PV Wire can be used within both grounded and ungrounded PV arrays.
Wire Design and Structure:-
PV Wire it is characterized by a thicker insulation jacket to provide additional mechanical protection against physical stress. USE-2 Wire it is used in less aggressive environment with less physical external stress. There for PV Wire it is manufactured from stranded conductors allowing for flexibility . Use-2 Wire can be manufactured from solid copper conductors or stranded copper clad aluminum and it is placed in locations with less mechanical stress and little as possible movement. Minimum conductor size for USE-2 wire is 14 AWG. Minimum conductor size for PV-Wire is 18 AWG.
PV Wire and USE-2 wire use thermoset insulation and jacket typically it is made of EPCV and/or XLPE. PV Wire uses an additional 15 mils of 90ºC wet and dry rated integral PVC insulation and jacket.
USE-2 Wire is typically installed underground or in similar locations with less flame propagation. PV Wire it is installed and exposed in an installation, therefor a flame test is required only for PV wire. Based on the wire structure for USE-2, overload test and mechanical abuse tests including crushing resistance and impact resistance are applicable only to USE-2 Wire.
PV Wire must comply with more stringent test requirements for requirements. It undergoes a 720-hour weather ohmmeter and -40ºC cold chamber conditioning. The requirements for USE-2 Wire are 300-hour weather ohmmeter and -25ºC cold chamber conditioning.
The information posted herein has been compiled by Clean Energy Brands from OEM product data and reputable publications. All rights reserved!