Copper building wire has been used since the early days of electricity because it sis one of the most conductive metals on earth. In fact, it is the second most powerful conductive metal next to silver, which is the most conductive. This is due to the fact that a copper atom has a free valence electron that activates when a potential is applied. With this scientific knowledge, copper cable was invented and has become the most popular metal used as a conductor. Copper is also a natural anti-microbial, which means it naturally fends off bacteria that can corrode the metal. Copper is malleable and easy to cut which also makes it a great material to work with.

Copper has proven itself as a reliable and effective metal for conductive purposes, but it still needs some additional protection to withstand the day-to-day punishment of Mother Nature. For that reason, there are insulations available for copper cables that significantly increase the cables’ longevity and resistance to corrosion over time. Without the insulation, the copper conductors are much more susceptible to being damaged by corrosion and there is much more of a chance that the cables will need to be replaced not long after they are installed. With the advent of insulated cables, the wiring that is put in place can be considered permanent and will stand up to more punishment over time so that no replacement installation is needed.

Crosslinked polyethylene insulation has become an popular material for the insulation of copper cables. Crosslinked polyethylene (also known as XLPE) is specifically designed as a protective coating for applications like chemical storage. It is created through a process of heating and cooling. Once the process has finished, the result is a highly durable, seem-less material that can coat metals to protect from chemical corrosion as well as abrasion and temperature damage.

Another reason crosslinked polyethylene is such a popular material for insulation of cables is because it requires virtually no maintenance once set in place. The crosslinked, seam-less construction makes the insulation into one large member that will not crack or split, even in dry conditions. Prior to the use of crosslinked polyethylene as an insulation, linear polyethylene and fiberglass-reinforced plastic were popular insulation materials. However, they both showed flaws that led to an early defectiveness in the cable. Linear polyethylene is prone to splitting and cracking because instead of crosslinked construction, it has a linear, side-by-side construction, which can split at the seams. Fiberglass-reinforced plastic is not a desirable insulation material because chemicals are able to penetrate the fibers and often requires special handling to avoid the insulation splitting during installation.

Nassau Electrical Supply’s insulated copper cables feature soft annealed Class B stranded copper conductors. The annealed copper used in this cable offers superior flexibility compared to standard copper. The copper is heated and slowly cooled, removing internal stress and making the copper more malleable. Each individual conductor is insulated with materials such as ethylene propylene rubber (EPR) or crosslinked polyethylene (XLP), moisture and heat-resistant materials that protect the conductors from abrasion and corrosion. The insulated conductors can be color coded for identification.

Many of these cables are available in multi-conductor cables. These cables are used to connect multiple circuits at once. In some locations is it mandatory that all circuits in a panel must be powered by one single cable, which is one reason that multi-conductor insulated copper cables are so popular. The assembly is a fitted with suitable fillers as necessary to keep the conductors from shifting within the jacket. The external jacket is composed of polyvinyl chloride. The outer layer is available in black or colors and is resistant to flame, moisture, oil, chemicals, and sunlight.

Per the National Electric Code, most of these cables are acceptable for use in Class I - Division 2, and Class II – Division 2 hazardous locations. The cables are suitable for installation in conduit, ducts, trays, or racks. Insulated copper cables can be installed in open-air applications with proper support from a messenger wire. The cables are also approved for direct burial. On average, these types of cables hold a temperature rating of 90°C when dry, 75°C when wet.

Many insulated copper conductors even pass VW-1 flame test and meet UL 1277 flame tray test. This is a test administered by Underwriters Laboratories, a compliance association that measures the safety and efficiency of electrical appliances. The flame test measures cables’ performance when being exposed to flame. Insulated copper cables that meet these UL requirements are suitable for use in locations with an increased risk of fire. This is another reason why insulated copper cables are often the best choice for electrical wiring in a commercial or industrial building. The benefit of a flame-retardant cable is that they may be salvageable after a fire or other catastrophe. Although a building fire is never a good thing, home and business owners can breathe a little easier knowing their electrical wiring is resistant to the devastation of fire.

Two very popular constructions of crosslinked polyethylene insulated cables are XHHW and XLP USE-2 RHH RHW-2 copper wires. Both types offer excellent resistant to corrosion, high heat and chemicals while protecting the conductor(s) from abrasion.

XLP USE-2 RHH RHW-2 Copper Wire employs a single copper conductor that is jacketed in a polyethylene insulation. The polyethylene jacket is a cross-linked insulation that enhances the lifespan of the cable by providing a flexible yet durable armor that protects the conductive components from high heat, moisture, abrasion, and chemicals that may corrode the copper. Copper cables offer many benefits over their aluminum competitors; they have extremely powerful conductive properties and retain their stability for a longer time than aluminum. The construction of XLP/USE-2, RHH, and RHW-2 copper wires offer an optimal combination of electrical and mechanical strength.

XLP USE-2 RHH RHW-2 Copper Wire is most commonly used within an electrical raceway such as conduit. Conduit is a tube or trough that channels the cable and further protects it from obstacles and abrasion. Conduit can be made of metal or plastic, the best option depending on the task at hand. RHH cable is most suitable for dry locations such as desert regions and should not be used in temperatures over 90°C. RHW-2 and USE-2 are suitable for both wet and dry locations and can tolerate temperatures up to 90°C. Type USE-2 conductors can be used for direct burial for service entrance cable.

When electrical cables need to be installed in areas with notoriously bad weather, XHHW Power Cable is often the preferred cable. XHHW Power Cable is armed with a heat and water-resistant polyethylene jacket that is capable of protecting the interior conductors from just about anything mother nature can throw its way. Functioning in temperatures up to 90°C in wet or dry locations, XHHW Power Cable has proven itself capable of handling tasks around the globe from the hot deserts of Dubai to Brazil’s watery rainforest.

The cable is also approved for use in hazardous locations where there is a high risk of fire or explosion. The cable passes UL flame test IEEE-383, which puts the cable up against flames that are up to 70,000 BTU. The PVC outer jacket takes most of the credit for this, being resistant to high heat and flame retardant. The cable also includes a crosslinked polyethylene insulation that offers additional protection against excessive wetness or dryness, heat, sunlight, and corrosive gasses or liquids.

The conductors in the XHHW cable are annealed copper conductors. The annealed copper conductors offer superior flexibility compared to standard copper wires, but offer the same powerful conductive qualities. The cable is available in a 3-conductor or 4-conductor construction. Included in the cable’s assembly is a bare copper ground wire, which is used to stabilize the cable’s electric current during use.

Both types of cables are extremely resilient and are approved for use in hazardous locations. It is most commonly used in industrial applications and to supply power to motors. The flame retardant insulation passes the Underwriters Laboratories Flame Test IEEE-383, a test that requires the product to be able to stand up to flames up to 70,000 BTU. It’s flame resistant qualities make the XHHW cable a cable of choice for use in areas with a high risk of fire. The cables are approved for direct burial and can also be installed in open air with support by messenger wire as well as in conduit or duct.

Nassau Electrical Supply carries an enormous selection of crosslinked polyethylene insulated copper cables including XHHW and XLPE USE RHH RHW-2 copper power cables. Call today and let our friendly, knowledgeable staff help supply you with the best cables to safely and efficiently complete your project.

XHHW-2 Copper Wire

XLP USE - 2 RHH RHW Copper Wire