The challenge:
- Create the first-ever 125°C rated 2-pair Category 5e cable for Commercial Vehicle applications.
Project background:
Champlain Cable was requested to quote an 18 AWG, 2 pair, 125⁰C rated Ethernet Category 5e cable for a large commercial vehicle manufacturer located in the United States. Typically, the conductor for Category cables range from 22 – 26 AWG. The 18AWG wire for this cable needed to meet SAE J1128 requirements and the lead wires had to meet a specific diameter range in order fit a connector seal.
Most cable people know there are only two insulating materials used for high speed internet cable (Category 5e as an example). FEP, a Teflon® polymer material rated at 200⁰C, is a common insulation material used for plenum rated Category Cables for use in commercial buildings. FEP is an excellent electrical insulation material with very high chemical resistance, but it is very expensive and difficult to print.
Polyethylene is another common material, rated at 80⁰C and is the other insulation material used for Category cables in the home and in riser locations of office buildings. Polyethylene is less expensive than FEP but its chemical resistance and flame retardant properties do not meet standards set by SAE J1128, the standard used for automotive wiring in North America.
The challenge:
Champlain Cable is one of the few wire and cable companies in the world with the capability to produce both Ethernet, Category Cables and Automotive and Commercial vehicle wires. Champlain Cable’s irradiation cross-linked compounds are uniquely positioned to meet the demands of the automotive and commercial vehicle environment and the demands of high speed Ethernet. The Champlain Cable engineering design team was up to the challenge to design and create the first 125⁰C rated Category 5e Cable for a Commercial Vehicle application.
Category 5e cables are designed to send signals ranging from 1 – 100MHz for a distance of 100 meters. The test standards have been established by EIA-TIA committee groups. The tests standards include characteristic impedance, insertion loss, return loss, powersum cross-talk etc.
In order for a Category cable to meet this standard, state-of-the-art process equipment is required, including dedicated extrusion lines and precise twinning and cabling machines to ensure uniformity in all aspects of lead wire and cable processing. Champlain Cable has been making Category cables for over 25 years and has the necessary processing equipment to assure the highest quality performance cables.
The solution:
Our design engineers chose the EXRAD® 150UT material for the primary wire insulation. EXRAD® 150UT has been used for over 15 years for Automotive powertrain wire and meets SAE J1128 TXL and ISO 6722-1 (150⁰C) rated thin wall requirements. EXRAD® 150UT insulation has a relatively low dielectric constant and low dissipation factor, two properties which are essential for sending a high frequency electrical signal 100 meters through a cable.
The original design concept of the cable utilized 18 19/.0092” AWG bare copper wire, as requested by the customer. The design models indicated that in order to meet the 100 ohm characteristic impedance, the lead wire diameter would be too large for the connector seal. The Champlain Cable design team then considered using a 0.75mm2 conductor, which is slightly smaller than 18 AWG. The metric sized 0.75mm2 conductor size met both the impedance and connector seal requirements.
The results:
The customer immediately accepted the concept of using the 0.75mm2 and the 150UT insulation. The design team moved ahead with a cable design, determined the lay lengths of the two twisted pairs and chose the EXRAD® 125ZH as the jacket material. This complete cable design was presented to the customer and was accepted.
Subsequently, Champlain Cable submitted a quotation for a prototype cable and the customer placed a sample order. The order was processed under engineering supervision at the Champlain Cable Colchester facility. Four weeks after receipt of the prototype order, the cable was completed. Electrical tests were performed using Champlain Cable’s state-of-the-art network analyzer. The cable met all the requirements of Category 5e.
The customer was extremely pleased with the results and proceeded to perform electrical tests in ovens, cold boxes and humidity chambers to assure the cable would perform well in extreme environments. The customer proceeded to make engineering drawings of the cable, utilizing the Champlain Cable design.
The EXRAD® 150UT, 2 pair 0.75mm2 125C rated Category 5e cable went in production less than six months later. The customer is very pleased with the results and is placing the cable system on all its vehicles. This is the only 125⁰C rated, 2 pair Category 5e cable utilizing SAE J1128 TXL primaries in the world!