DUZX. Communications Cable
Keywords: CM, CMP, CMR
In the field of network cable and low-voltage cable, CM, CMP, and CMR are flame-retardant ratings defined by the National Electrical Code (NEC). They indicate the cable’s fire safety performance and dictate where they can be legally installed.
Comparison:
| Part Name | Safety Level | Installation Area |
|---|---|---|
| CMP Cable | Highest (Lowest Smoke & Flame Spread) | Plenums (Air Handling Spaces) |
| CMR Cable | High (Prevents Vertical Flame Spread) | Risers (Vertical Shafts between floors) |
| CM Cable | Standard (Basic Flame Resistance) | General Purpose (Single floor, non-plenum areas) |
A higher-rated cable, such as CMP cable, can typically be used in place of a lower-rated one, like CMR cable, or CM cable, but it is more expensive. The reverse is not permitted by building codes.