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Want to know the difference between CM, CMR, and CMP Ethernet cables? This guide will explain fire resistance levels and ideal applications, helping you choose the right cable for your needs
What are the ratings for Vest Ethernet Cable?
Ethernet cable jacket ratings evaluate safety and performance, as defined by the National Electrical Code (NEC). These ratings ensure the safe and proper use and installation of Ethernet cables in various environments. The letters CM, CMR, and CMP represent different types of cable jacket ratings, and each indicates different levels of fire resistance and safety for different applications.
CM cable jackets refer to the outer covering of multi-purpose communications cables, which are usually made of PVC. They are cost effective but have potential safety concerns regarding smoke and gas emissions during a fire.
These ratings determine where Ethernet cables can be safely installed. From residential settings to complex commercial installations, knowing the correct type of cable jacket rating can increase cable performance and ensure compliance with safety regulations.
Below is a breakdown of what these assessments mean and how to apply them.
Common Ethernet cable jacket ratings: CM, CMR, CMP
The three main types of Ethernet cable jacket ratings are CM (Multi-Purpose Communications), CMR (Communication Raiser), and CMP (Complete Communications). Each classification assigns Ethernet cables to specific uses based on their fire resistance properties. CM cables, for example, are made of polyvinyl chloride (PVC) and are most commonly used as general-purpose communications cables suitable for patchy areas.
On the other hand, CMR cables are designed for vertical spaces such as risers and have more stringent fire resistance requirements than CM cables. CMR cable jackets are made from materials such as low smoke PVC or fluoroethylene polymer and are designed to prevent the spread of fire between floors, making them ideal for multi-storey buildings.
Finally, CMP cables are designed for use in ventilation spaces, such as air ducts, and have the highest level of fire resistance to meet stringent safety standards. Pleated rated cables are essential for areas with air circulation such as suspended ceilings and raised floors due to their stringent regulations regarding flame spread, smoke emission and toxicity.
To determine the rating of an Ethernet cable jacket, check the markings printed along the cable jacket, which usually includes its UL listing and fire safety rating, such as CM, CMR, or CMP. These designations, certified by Underwriters Laboratories (UL), indicate the cable’s compliance with fire safety standards, with CMP being the highest rating for public spaces.
Knowing these common cable jacket ratings will help you choose the right cable for your specific needs. Whether you need a basic cable jacket for general use or a more secure CMP cable for high-risk areas, understanding the differences between CM, CMR, and CMP will ensure you make the best choice for your installation, including using a CMP cable jacket.
What is a CM rated Ethernet jacket?
CM cables, or multi-purpose communications cables, are suitable for general use in standard and non-public areas. They are made of polyvinyl chloride (PVC) and must pass standardized flammability testing to receive their rating. While CM cables have basic fire resistance properties, they meet minimum safety standards, making them basic cable jacket rated for general use.
Primarily used for horizontal wiring within a single floor or area, CM cables are ideal for running cables in walls or rooms where fire ratings are not as stringent, such as in single-story dwellings. CM cables provide a cost-effective solution for residential installations, providing adequate safety and performance without the need for higher fire resistance.
Unless otherwise stated, most Cat6 and Cat6a Ethernet cables are CM rated, which means they are generally safe for your home.
What is a CMR rated Ethernet jacket?
CMR cables, or Communications Riser cables, are designed for vertical spaces and have more stringent fire resistance requirements than CM cables. Made from materials such as low-smoke PVC or fluoroethylene polymer (FEP), these cables have enhanced fire resistance properties. CMR cables prevent the spread of fire between floors, making them ideal for vertical installations in multi-storey buildings.
CMR Ethernet cables are suitable for vertical installations in multi-story buildings due to their physical composition and fire resistance capabilities. CMR rated cables can replace CMR rated cables, providing greater fire resistance for vertical installations. Although they cannot be used in public spaces, they provide a higher level of safety for vertical operation, making them a versatile and essential component in multi-storey building installations.
What is a CMP rated Ethernet jacket?
CMP cables, or Communications Plenum cables, are designed for use in air circulation spaces, such as areas above ceilings or raised floors where air is handled. With the highest level of fire resistance among Ethernet cable ratings, they produce minimal smoke and toxic gases when burned, making them ideal for environments requiring strict safety measures.
CMP cables are typically made of low-smoke PVC or fluoroethylene polymer (FEP), so they emit minimal toxic fumes, which is vital given the airflow within these environments. Its design ensures enhanced safety and compliance with the highest fire safety standards, making it the best choice for public spaces.
Compare CM, CMR and CMP Ethernet cable jackets
Comparing CM, CMR and CMP cables reveals significant differences in fire resistance, usage scenarios and cost. Made from relatively inexpensive polyvinyl chloride (PVC), CM cables provide essential fire resistance properties and are ideal for unfinished areas in single-storey buildings.
CMR cables, with high flame resistance, are designed to prevent the spread of fire between floors, making them suitable for vertical installations in multi-storey buildings.
CMP cables have the highest fire resistance, and produce minimal smoke and toxic fumes when burned, making them essential for air circulation spaces such as those above ceilings and under raised floors. The cost of these cables reflects their fire-resistant properties, with CM cables being the most cost effective, CMR cables being moderately priced, and CMP cables being the most expensive due to their advanced safety features.
Fire resistance and safety standards
Ethernet cable jacket ratings help evaluate the cable’s fire resistance and safety based on where it will be used. These ratings are necessary to comply with safety standards, such as those specified in the National Electrical Code (NEC). For example, CMP cables must pass stringent tests to meet these standards, ensuring that they produce minimal smoke and toxic fumes during a fire.
The construction of CMP cables emphasizes low smoke emission to enhance safety in the event of a fire. In contrast, CMR-rated cables, made of low-smoke PVC or fluoroethylene polymer, prevent the spread of fire between floors but are still capable of emitting some smoke and toxic halogens when burned.
CM cables have the lowest fire resistance and are only suitable for areas with minimal fire risk.
Usage scenarios and applications
CMP cables are most commonly recommended for various cabling needs due to their high fire resistance and safety in public spaces, where air is handled. These cables are essential in commercial and industrial environments where strict fire safety measures are required.
For residential installations, CMR cables are often recommended to enhance fire protection, especially in multi-storey residences. CMR cables can be used in place of CM cables, providing more versatility for different installations without compromising safety.
While CM cables are suitable for basic residential use, CMR cables provide a safer and more reliable option for complex setups. If you are installing an Ethernet cable in your home because you are upgrading to a wired gaming connection or a wired streaming connection for your TV, a CM-rated Ethernet cable will usually suffice.
Cost considerations
CMP rated cables are generally the most expensive due to their enhanced fire safety features. The specialized manufacturing and materials used in CMP cables, such as low-smoke PVC or fluoroethylene polymer, contribute to their high cost. However, this investment can be justified by increased safety and compliance with stringent fire codes.
While CMR cables are less expensive than CMP cables, they still provide significant fire resistance, making them a cost-effective option for vertical installations. CM cables, being the least expensive, are suitable for standard, non-public areas where the risk of fire is minimal.
Balancing cost and safety needs is essential when choosing the right Ethernet cable for your installation.
Choose the right Ethernet cable jacket for your needs
Choosing the right Ethernet cable is crucial to ensuring the safety and optimal performance of your network. When choosing Ethernet cables, consider factors such as safety, performance requirements, and budget constraints. The category of Ethernet cable, such as Cat 5e or Cat 6, is key to determining speed and bandwidth capabilities.
Understanding the differences between CM, CMR, and CMP cables will help make an informed decision based on specific needs. Whether you are setting up a home network or a complex commercial installation, choosing the right cable ensures efficient and secure network performance.
Residential facilities
CMR cables are typically suitable for residential operation, providing a good balance of security and performance for residential applications. Suitable for non-public spaces, it is a versatile option for standard installations. Routing CMR cables through walls and floors in residential appliances ensures safety and performance without requiring higher fire resistance.
CMR cable is suitable for most home applications. However, it is not suitable for use in ductwork. For single-storey dwellings, CM cables may also be a cost-effective option, due to the minimal fire risk involved.
Commercial and industrial facilities
In commercial and industrial environments, choosing the right cable ensures performance and safety. CMP cables are preferred for applications where fire safety is critical, such as in public areas where air is handled. These cables provide the highest level of fire resistance and comply with stringent safety standards.
CMP cable is generally recommended for any cabling needs, especially in difficult environments. Investing in CMP cables ensures maximum safety and minimum risk, making them the best choice for commercial and industrial installations.
Frequently asked questions
What are the ratings for Vest Ethernet Cable?
Ethernet cable jacket ratings indicate the fire resistance and safety standards of the cables, as rated by the National Electrical Code (NEC). Understanding these classifications is critical to ensuring compliance and safety in facilities.
What is the difference between CM and CMR cables?
CM cables are designed for unfinished areas, while CMR cables are specifically designed for vertical spaces and provide enhanced fire resistance to limit fire spread between floors.
Why are CMP cables more expensive?
CMP cables are more affordable because they offer superior fire resistance, including low smoke emission and minimal toxic fumes, making them suitable for use in public areas.
Can CMR cables be used instead of CM cables?
Yes, CMR cables can replace CM cables because they offer enhanced fire resistance and versatility for different installations.
What cable should I use for my home network?
For your professionally installed home network, CMR cables are recommended, as they provide the right balance between security and performance. In unfinished areas of a single-story dwelling, CM cabling may also be sufficient.
