F.A.Q. - Frequently Asked Questions
 
  1. What are the possible applications for cables insulated with "silicone" and "fluorocarbon resins"?
  2. Can silicone and fluorocarbon resin cables be used for both "fixed" and "mobile" installations?
  3. Are CET cables resistant to all chemical substances?
  4. When we talk about resistance to temperature, do we refer to "continuous" or "peak" temperature?
  5. What are the biggest and smallest sections of cables that CET can produce?
  6. Concerning the colour of the insulation, can it be produced in all colours?
  7. What's the difference between "tear resistant" and "anti-laceration" cables?
  8. What is the difference between "certified" and "non-certified" cables?
  9. What is the difference between "standard" and "special" cables?
  10. Is it possible to obtain a certification not shown on CET's product catalogue? If so, how long would it take to get it?
  11. What is the difference between the choice of a "red copper, tinned copper, silver-plated, nickel-plated or pure nickel conductor"?
  12. When is a "screened" cable rather than a "shielded" one chosen?
  13. What is the minimum quantity per order?
  14. Which is the average delivery time of a "single core" and a "multicore" cable respectively?

1. What are the possible applications for cables insulated with "silicone" and "fluorocarbon resins"?
Cables insulated with silicone.
The peculiar characteristics and properties of the silicone elastomer permit electric cables insulated with silicone to have an extremely vast range of uses and, above all, high performance at a wide range of temperatures (from -60° to +180°C and up to 250°C). Therefore the use of silicone insulated cables are various:

  • Power supply for lighting equipment;
  • Cabling for class B-F-H electric motors;
  • Ignition for burners, heaters and cookers;
  • Continuous power sources for ovens and resistances;
  • Wiring in automotive
  • Wiring in railways
Cables insulated with fluorocarbon resins
Albeit fluorocarbon resins (ETFE, FEP, MFA, PFA) are the direct descendants of polytetrafluoroethylene (PTFE) and have got analogous properties of mechanical and chemical resistance, they have different characteristics of thermal resistance. First of all, it should be noted that cables insulated with fluorocarbon resins usually have smaller dimensions than most electric cables insulated with other materials (with equal performance). This is due to the high constant of dielectric rigidity that distinguishes this type of insulating material. Therefore, with an extremely high mechanical resistance and optimum compatibility with chemical substances, as well as the usually reduced dimensions, these cables can be used for a number of different applications: from lighting fixtures to household appliances, information technology equipment and the aerospace industry, as well as any type of civil or military application.

2. Can silicone and fluorocarbon resin cables be used for both "fixed" and "mobile" installations?
Cables insulated with silicone rubber are suitable exclusively for static use. This limitation is substantially due to the reduced mechanical resistance offered by the silicone elastomer. In fact, cables insulated with silicone rubber are easy to lacerate and therefore are not suitable for mobile applications or considerable movement during installation. On the other hand cables insulated with fluorocarbon resins are suitable for both fixed and mobile installations.

3. Are CET cables resistant to all chemical substances?
This is true in the case of cables insulated with fluorocarbon resins while for cables insulated with silicone it is not. It is always recommended to require specific details to CET ELETRIC technical staff, according to the type of contact the cable in object is expected to have with chemical agents and substances.

4. When we talk about resistance to temperature, do we refer to "continuous" or "peak" temperature?
When we talk about resistance to temperature, we always refer to the maximum operating temperature of the cable; otherwise, if we refer to resistance to a peak temperature, this will be explicitly indicated by mentioning the value of the continuous temperature separately.

5. What are the biggest and smallest sections of cables that CET can produce?
Again in this case a distinction must be made between the production of cables in silicone and the production of cables in fluorocarbon resin. In the case of silicone production, the smallest section is 26AWG (0.14 mm2), while the largest is 300 mm2. Concerning cables produced with fluorocarbon insulation, on the other hand, the smallest section is 30AWG (0.05 mm2), while the biggest section measures 6.00 mm2. For the latter, however, it is necessary to make a distinction concerning the production of cables insulated with PTFE, since a taping process is used for this type of production instead of an extrusion process: while the largest section remains the same, the smallest section is 24AWG (0.22 mm2). Because of the pull exerted on the PTFE tape by the conductor, a section smaller than 24 AWG might break during the taping process.

6. Concerning the colour of the insulation, can it be produced in all colours?
In the case of cables insulated with silicone rubber, there are no problems in producing all of the colours and even two-colour cables. With fluorocarbon resins, two-colour cables cannot be produced, except for yellow-green ones.

7. What's the difference between "tear resistant" and "anti-laceration" cables?
The difference is implied by the two definitions: an anti-tear insulation has got a high longitudinal mechanical resistance (it stands up to the force of traction, that is to say, to tearing); in the case of an anti-laceration cable, on the other hand, the insulation grants high resistance to transversal stress, typical of cutting or abrasion due to rubbing against sharp parts, such as corners. A cable with anti-laceration properties is definitely also an anti-tear cable, while the converse is not necessarily true. For cables insulated with silicone, the above-described difference is significant; but for cables insulated in fluorocarbon resin this type of problem is inexistent, because they have got such great mechanical properties that they can only be compared to anti-laceration cables.

8. What is the difference between "certified" and "non-certified" cables?
All cables must follow specific standards in order to guarantee that they function properly in relation to the operating conditions they have been designed for; nevertheless, although they are built according to the precise dictates of standards, some cables bear no trademark. Other cables, however, are identified by the standards issued by certification institutes because they are built in full respect of the directives concerning specific operating conditions (voltage, temperature, type of application, etc.) indicated by the organisations themselves. Moreover these cables have been tested by the laboratories of above institutes, in order to verify whether they correspond to the standards related to the type of performance they have been built for. No need to underline that, under similar operating conditions, certified cables are definitely of higher quality with respect to those that bear no homologation. So it is preferable to use a certified cable whenever we need to ensure a very high standard of quality to the final application of the cable (lighting equipment, hobs, ovens, etc…)

9. What is the difference between "standard" and "special" cables?
A standard product is built to satisfy common operating conditions, for a good number of applications. A special product, on the contrary, is built to meet specific requirements under operating conditions which are not common to other applications. Special cables are in most cases built according to customers' technical specifications and/or samples.

10. Is it possible to obtain a certification not shown on CET's product catalogue? If so, how long would it take to get it?
In most cases a new homologation involves burdensome costs, both from the point of view of production and the homologation procedure itself. Therefore, when the market volume is sufficient to motivate this type of expense, a new homologation will definitely be undertaken and obtained. Concerning the time involved, this is a variable that is tied to many different factors. Not least important among these is the availability of the testing laboratories of the certification agencies in question. Generally, an homologation procedure will last no longer than three months, from the date of the request to the final certification.

11. What is the difference between the choice of a "red copper, tinned copper, silver-plated, nickel-plated or pure nickel conductor"?
The difference is substantially connected to the different thermal properties of the conducting insulators. Each kind of conductors can offer a certain electrical resistance that is a which is directly proportional to the temperature range. Therefore the choice of a specific material is strictly related to the operating temperature of the application for which the cable will be used. Synthetically, the following distinction can be made:

  • RED COPPER up to 150 °C;
  • TINNED COPPER up to 220 °C;
  • SILVER PLATED AND NICKEL PLATED COPPER up to 260 °C.
  • PURE NICKEL for temperatures exceeding 260 °C.
12. When is a "screened"cable rather than a "shielded" one chosen?
Screening is used to reduce possible electromagnetic interference due to the passage of electricity through the conductor when the cable is situated in the proximity of electronic circuits. In fact, the voltage generates an electromagnetic field during its passage, which may interfere with electronic equipment. The presence of the screen permits the reduction of this type of phenomenon; in fact, when the electromagnetic waves propagate from the conductor towards the surrounding area, they encounter the screening they are directed to by the current, which is the result of the electric power originated by the waves themselves. Thus, the electromagnetic effect is depleted by a barrier of copper sheathing. Shielding is obtained with a sheath of steel and has got the sole purpose of protecting the silicone cable (which is rather fragile) from potential heavy contact that could compromise the integrity and functional efficiency of the cable.

13. What is the minimum quantity per order?
Minimum quantities depend on the type of cable; consequently it is advisable to request this piece of information when sending your inquiry.

14. Which is the average delivery time of a "single core" and a "multicore" cable respectively?
In the case of standard cables, it takes from 2 to 3 weeks to deliver a single core cable while four weeks are needed for a multicore cable. In the case of special cables, the average time depends on the type of manufacturing process to be performed. For example, the average time for a screened multicore cable ranges 5 to 6 weeks. Nevertheless, this type of information is susceptible to variation according to the production requirements. Therefore it is recommended to ask for this information to CET's sales department directly.

 

 
home page   e-mail   contacts   search   site map Top