How to choose cables with different flame retardant levels - Database & Sql Blog Articles

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Fire protection standards vary significantly across different regions globally. In North America, the UL (Underwriters Laboratories) rating system is widely used and ranks from highest to lowest as follows:

  • Flame Retardant CMP – For use in ventilation ducts or air return plenums.
  • Non-Combustion Trunk Line CMR – Suitable for vertical trunk lines and horizontal areas.
  • Non-Combustion Commercial Grade CM – For horizontal installations in commercial settings.
  • Non-Combustion General Purpose CMG – Also for horizontal areas but with a lower rating than CM.
  • General Home Grade CMX – Must be installed horizontally only.

CommScope SYSTIMAX’s 20×× series cables are classified as CMP, meeting the highest fire safety standard. The 10×× series cables are rated at the CMR level.

In Europe, low-smoke, halogen-free cables follow three main standards:

  • IEC 60332-3 or IEC 60332-1 – Focuses on flame spread and flame retardancy.
  • IEC 61034 – Measures smoke production during combustion.
  • IEC 754 – Evaluates toxicity and corrosiveness of gases produced during burning.

The IEC 60332-1 standard is designed for single-wire testing and has a lower fire resistance rating. It can still smolder after the flame is removed, and it produces high levels of carbon monoxide. In contrast, IEC 60332-3 involves testing with a bundle of wires and provides a much higher level of fire protection. This standard is more effective in preventing the spread of flames and reducing potential chain reactions caused by fires.

IEC 60332-3 is further divided into three categories: A, B, and C. Class A requires more cables to be tested, and the flame burn time is 40 minutes, making it more stringent. Class C, on the other hand, only requires a 20-minute burn test, resulting in a less strict rating. Therefore, cables that meet IEC 60332-3A are considered more reliable and safer than those meeting IEC 60332-3C.

CommScope SYSTIMAX’s 30×× series cables are low-smoke, halogen-free cables that comply with the highest IEC 60332-3A standard.

When comparing flame retardancy between IEC standards and UL ratings:

  • IEC 60332-1 is equivalent to the UL CM rating.
  • IEC 60332-3 corresponds to the UL CMR rating.

For critical infrastructure or applications where personal safety is a top priority, we strongly recommend using UL CMP-rated cables or IEC 60332-3A low-smoke, halogen-free cables. These options provide the highest level of fire safety and minimize risks in case of emergencies.

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