USE-2 Solar Cable
WesBell USE-2 stands for Underground Service Entrance because it's used an underground cable without conduit or tray. It is rated for 600 volts and 90°C. USE-2 is also known as solar wire or solar cable because it's commonly used for solar installations where sunlight is an issue (sunlight resistance cable) for rooftop applications.
USE-2 Cable Construction
The acronym stands for Underground Service Entrance and it is also known as solar wire. It’s designed with small copper strands for flexibility and would tightly before being wrapped with a cross linked polyethylene insulation. The insulation has numerous approvals so that it can be buried underground and used as “solar wire” for solar panel installations. Sunlight can be a bare on cable insulation when sitting on rooftops for its life.
Sizes range from 14 AWG to as a big as 4/0 (0000 AWG), or even bigger upon request. For quick delivery and low quantity orders the jacket color will be black, but for larger orders that can wait about 5 weeks for the cable to be delivered, can choose a specific color before it’s manufactured. The same approvals will apply for different color options.
USE-2 Cable Approvals
The approvals include ASTM, UL44, UL854, AA59544, NEMA WC 70, RoHS and REACH which each designate something specific. The UL standard for 854 tests and approves cables to meet certain criteria, “Table 1 provides a summary of the maximum conductor temperature, voltage ratings, and the number of insulated conductors for the types to which this Standard applies.” Instead of requesting more information from the manufacturer you could review the UL standards on their website to see how the third party tested the cable. Once UL stamps an approval on a cable it becomes much closer to a guarantee.
USE-2 Cable Applications
Generally, it’s used to install solar panels and used as a service entrance cable when a single conductor cable needs to be buried directly in the ground. UFB cable is a multiconductor cable that is approved for direct burial, but as a single conductor option, solar wire is the best fit. It can be used in all wet and dry locations, and in sunlight resistant installations. This cable has become very popular over the last 5-10 years since solar panels have been increasing in demand throughout the industry.
“Solar cable is the interconnection cable used in photovoltaic power generation. A solar cable interconnects solar panels and other electrical components of a photovoltaic system. Solar cables are designed to be UV resistant and weather resistant. It can be used within a large temperature range and are generally laid outside. (Wikipedia)”
USE-2 Cable Manufacturers
There aren’t as many manufacturers that design and make this cable, WesBell buys it from Southwire and General Cable. Here is the main description on Southwire’s data sheet, “Southwire Type RHH or RHW-2 or USE-2 conductors are used with conduit as specified in the National Electrical Code. When used as Type USE-2 the conductor is suitable for use as underground service entrance cable for direct burial at conductor temperatures not to exceed 90°C.”
When looking for cost savings you can look to aluminum solar wire because it’s much cheaper, lighter to ship and in less demand than copper. Copper is a better conductor of electricity which means you’ll need to use a bigger size aluminum conductor for the same application. If 8 AWG copper has been approved for an application, then the same application would need 6 AWG or 4 AWG aluminum wire. However, it would still prove to be a cheaper overall cost for the job.
- Bare copper
- RHH RHW-2 XLP insulation
- NEMA WC 70
- Underground service entrance cable
- Direct Burial
- Sunlight resistant
- Wet or dry locations