What is the maximum untwist allowed for category 3 cables?

The maximum untwist allowed for category 3 cables is indeed 3 inches. This standard is based on the need to maintain the cable's performance characteristics and reduce interference, particularly from crosstalk. The twisted pair design of these cables serves to cancel out electromagnetic interference (EMI) that could disrupt signal transmission.

Maintaining the integrity of the twists within the pairs is crucial for the cable to function effectively, especially over longer distances. Allowing an untwist longer than 3 inches can significantly degrade the cable's performance, increasing the chance of crosstalk and reducing overall signal quality. Therefore, the 3-inch limit is established as a balance between ease of installation and the maintenance of signal integrity.