One, Power Cables

Power cables are the transmission lines for supplying power to system equipment, with the power lines of the system equipment interconnected through power cables. The system can adopt a centralized AC 85～240V power supply method, or a local AC 85～240V power supply method. (Explosion-proof public address stations use wide voltage power supply.)

★Advantages and Disadvantages of Centralized Power Supply: Easy equipment installation. When the power supply lines are long and the power supply current is high, the cable diameter requirement for power cables is larger, and the price of power cables is higher.

★ Drawbacks of on-site power supply: Lower requirements for power cables, and relatively inexpensive cable prices. However, as the equipment needs to be powered on-site, installation is not very convenient.

Power Cable Requirements

To minimize the attenuation of power transmission at AC220V, it is required that the power cable be a 3-core cable with specific requirements for wire diameter. The minimum cross-sectional area of each core cable should be at least 2.5mm², with the wire diameter increasing as the transmission distance increases.

Signal Cables

Bus cables serve as the common channel for signaling transmission and control, as well as voice transmission between system devices. System devices connect their individual signaling transmission lines, signaling control lines, and voice transmission lines in series via the bus cables.

Bus Cable Requirements

To minimize signal and voice transmission attenuation caused by bus cables, and to reduce external interference from induction and radiation on bus cables, it is required that multi-core shielded cables be used for bus cables, with specific requirements for the wire diameter, which should be 0.5mm for each core.

Three: Speaker Cable

Speaker cable is the connecting cable between the intercom and the speaker, transmitting the audio signal output. The transmission distance between the speaker and the intercom cannot exceed 30 meters.

Speaker Cable Requirements

To minimize external interference caused by speaker cable inductance and radiation, it is required that the speaker cable be made of a 2-core shielded cable with specific requirements for wire diameter, with each core having a cross-sectional area of 1.0 mm².