What occurs if communications wires are attached to a cross-arm carrying electrical conductors?

When communications wires are attached to a cross-arm carrying electrical conductors, it indeed poses a fire hazard. This situation arises because the electrical conductors can carry high voltage, and if there is any fault or insulation failure, the energized conductors may come into contact with the communications wires. This can lead to arcing or voltage surges that could ignite nearby materials, thereby creating a fire risk.

Additionally, the presence of both high voltage electrical conductors and low voltage communications wires on the same supporting structure increases the likelihood of electrical interference and potential damage to the communication system. It is critical to adhere to safety standards and regulations that dictate proper separation between high voltage and low voltage systems to mitigate such hazards.

The practice of combining these two types of wires without adequate insulation or protection is generally not advisable due to the associated risks. Codes and standards typically require specific clearances and installation practices to ensure safety and reliability in the setup of electrical and communication systems.