If you’ve ever ordered tray cable, you’ve likely been inundated with options. From conductor counts and shields to color codes, this multi-purpose building wire is the ultimate mix-and-match product.
Among the many options are jackets – the outermost layer of the cable. Like the jackets you and I wear to keep warm during the winter, a tray cable jacket protects conductors, shields, and insulation from damage. Depending on the application and environment, contractors and electrical workers have several tray cable jacket options, including chlorinated polyethylene (CPE).
But what makes this synthetic polymer so versatile, and where do we use it?
Like other plastics, CPE is a synthetic material made from a polymer.
Polymers (Greek for “many parts”) are long, repeated molecule chains that combine to create a chemical compound. Essentially, they give CPE and other plastics their strength, resistance, and other attributes.
CPE jackets and insulation provide excellent fire, chemical, UV, oxidation, abrasion, water, and acid resistance. Its polymer chain also makes CPE highly durable and somewhat bendable, though it isn’t as flexible as other compounds.
Unlike other insulation types, CPE is a rare material with thermoset and thermoplastic jacketing variations.
What does this switch-hitting designation mean for tray cable products? It comes down to performance.
Though both configurations provide excellent protection, thermosets are more effective in extreme temperatures. Of course, the added protection often comes at a higher cost than the much more common thermoplastic version.
In addition, CPE is more than simply a tray cable jacketing material. The polymer is also a common choice for conductor insulation, thanks to its many protective properties. When fire resistance is critical, a CPE insulation and jacketing combination offers premier protection across many applications.
Like most tray cable products, you can find CPE insulation and jacketing used throughout many industries, including:
Beyond these uses, chlorinated polyethylene jacketing makes sense in any location where fire, chemical, and abrasion resistance is important.
CPE is also a suitable substitute for projects where PVC insulation may struggle. PVC works well against high heat but underperforms against water, abrasion, and low temperatures.
While CPE has a lot of positives, it isn’t the be-all-end-all tray cable jacketing type.
Generally, CPE jacketing performs better overall than PVC, offering better flexibility in low temperatures, alongside better water, abrasion, and flame resistances. CPE is also more effective than polyurethane (PUR), which struggles with flame resistance and isn’t as durable.
With that said, CPE may not be as safe as low smoke zero halogen (LSZH) jacketing, which is the best choice for public areas.
In other cases, CPE works as a replacement for chlorosulfonated polyethylene (CSPE). Although CSPE is a fantastic jacketing product, it contains sulfur dioxide and chlorine in its polymer chains. These additives give it incredible resistance to chemicals, UV, weather, and heat, but make it tough to recycle and contribute to plastic pollution. CPE is often a more cost-effective and greener choice for many applications.
The best jacket for the job depends on the application and the environment. Sometimes, insulation types are great for one project but could underperform or be overkill for another.
For example, low smoke zero halogen (LSZH) jacketing is best suited for busy office buildings, hospitals, and schools. PVC excels in gas and oil applications where chemical exposure is a constant threat. CPE offers solid protection across the board but struggles in tight spaces and high-flex areas.
Note: Kris-Tech tray cable is UL 1277 compliant, direct burial and exposed run (-ER) rated, and follows National Electrical Code (NEC) standards.
Though it has many strengths, CPE is only one of many wire and cable jacketing options.
As always, research and learn as much about the application and environment as possible. If you have questions or concerns about which tray cable jacketing type makes the most sense for your next project, ask for help.
Your local code enforcement official can help you understand NEC guidelines and address potential concerns. Kris-Tech also has a team of wire experts to help you find the right product to match your needs.
