Every Renewable energy system needs Solar cables, weather its to connect to the panels, ground/ bond the system, interconnect components or batteries, and there are different type of cables used to do these tasks currently we have placed all of these cables under the Solar Cables category.
Here is what wiki has to say about Solar /. PV Cables
A solar cable is the interconnection cable used in photovoltaic power generation. Solar cables interconnect solar panels and other electrical components of a photovoltaic system. Solar cables are designed to be UV resistant and weather resistant. They can be used within a large temperature range and are generally laid outside.
More of our thoughts and observations about solar cables in general
These cables are available in black, red, white and other colors with voltage ratings of 600, 1000, 2000,volts DC they are sunlight resistant and direct burial rated UL listed and have the specifications clearly printed on the cable for easy identification of the make up of the wire
There are generally three types of insulation that you will commonly find out there USE-2, PV, RHW-2
Aluminum or Copper: The two common conductor materials used in residential and commercial solar installations are copper and aluminum. Copper has a greater conductivity than aluminum, thus it carries more current than aluminum at the same size.
Aluminum may be weakened during installation especially during bending, however it is less expensive than copper wires. It is not used (not permitted) for interior home wiring, as they are used in larger gauges for underground or overhead service entrances and for commercial operations.
Solid or Stranded: The cable could be solid or stranded, where stranded wires consist of many small wires that allow wire to be flexible. This type is recommended for larger sizes. The current tends to flow on the outside of the wire, thus stranded wires have slightly better conductivity as there is more wire surface.
Insulation: The insulation covering wire can protect the cable from heat, moisture, ultraviolet light or chemicals.
- THHN is commonly used in dry, indoor locations.
- THW, THWN and TW can be used indoors or for wet outdoor applications in conduit.
- UF and USE are good for moist or underground applications.
- PV Wire, USE-2 and RHW-2 cables can be used in outdoor and wet conditions where their outer cabling is UV and moisture resistant. They must be sunlight resistant.
Color: Electrical wire insulation is color coded to designate its function and use. For troubleshooting and repair, understanding the coding is essential. The wiring label differs according to AC or DC current.
Here is a simple table for color coding.
| Alternating Current (AC) | Direct Current (DC) | ||
| Color | Application | Color | Application |
| Black, Red or Other Color | Un-Grounded Hot | Red | Positive |
| White | Grounded Conductor | White | Negative or Grounded Conductor |
| Green or Bare | Equipment Ground | Green or Bare | Equipment Ground |
For your convenience I have added the table from National Electrical Code that shows conductor applications and insulations. Please refer to NEC Article 310, page 15 – Table 310.13 (.PDF document) for the expanded version of the table.
| Type Letter | Name | Max. Provisions | Application Provisions | Insulation | Outer covering |
| THHN . | Heat Resistant Thermoplastic | 90 C, 194 F | Dry or Damp Locations |
Flame retardant,
heatresistant
thermoplastic
|
Nylon jacket or equivalent |
| THW | Moisture& Heat Resistant Thermoplastic | 75-90 C, 167-194 F | Dry or Wet Locations |
Flame retardant,
moisture and
heat resistant
thermoplastic
|
None |
| THWN | Moisture& Heat Resistant Thermoplastic | 75 C, 167 F | Dry or Wet Locations |
Flame retardant,
moisture and
heat resistant
thermoplastic
|
Nylon jacket or equivalent |
| TW | Moisture resistant thermoplastic | 60 C, 140 F | Dry or Wet Locations |
Flame retardant,
moisture resistant
thermoplastic
|
None |
| UF and USE | Underground Feeder & Branch Circuit Cable- Single Conductor | 60-75 C, 140-167 F | See Article 338 and 339: Service Entrance |
Moisture and
heat resistant
|
Integral
with insulation and Moisture resistant
|
| USE-2* and RHW-2* | Moisture resistant thermoplastic and Branch Circuit Cable- Single Conductor | 90 C, 194 F | Dry or Wet and Service Entrance |
Moisture and
heat resistant
|
Moisture resistant with insulation
|
| PV Wire** | Thicker insulation or jacket to provide additional protection against the abuse that USE-2 wire may receive. | 90 C (194F) wet, 150 C (302 F) dry | Dry or Wet and Service Entrance | Moisture and heat resistant | Moisture resistant with insulation |
*Mentioned as a page note: “Wire types designated with the suffix “2,” such as RHW-2, shall be permitted to be used at a continuous 90°C (194°F) operating temperature, wet or dry.”
**NEC finds the use of PV Wire adequate and necessary in ungrounded systems.
hope this information helps you
