Common electrical wires in everyday life include hard wires and flexible wires. Commonly used cables can be categorized as single-core and multi-core. Single-core cables have only one core wire. Multi-core cables have multiple cores (e.g., 4-core, 5-core, etc.). Commonly seen RVS, RVV, and RVVP cables are examples of multi-core cables. Today, we'll introduce the characteristics of multi-core cables.
1. Multi-core Cables
Multi-core cables are cables with more than one insulated core.
Common multi-core cables include two-core, three-core, four-core, five-core, 3+1-core, 3+2-core, and 4+1-core cables. Control cables can have up to 61 cores.
A two-core cable is used to control a single appliance. One wire is the live wire and the other is the neutral wire. A switch is connected in series with the middle of the live wire to turn the power on or off.
A three-core cable is typically used for 380V power lines. One wire is the neutral wire and the other two are the live wires. The connection between the appliance and the power source is controlled by a three-way barrier switch or magnetic starter. It is commonly used for three-phase motors or welding machines.
A four-core cable is typically used for service power lines. One wire is connected to the neutral wire, and the other three are connected to the transformer's live wires A, B, and C, respectively. The power of all the wires at the end is roughly equal, ensuring a stable transformer output.
A five-core cable is often used in a small space with many appliances. This allows it to control five appliances. A multi-switch is connected in series with each of the five live wires, and the five appliances share a common neutral wire.
II. Applications of Multi-core Cables
1. Multi-core cables are generally flexible and are often used in portable and temporary power distribution facilities. They are easy to install, drag, and move. However, after being exposed to high temperatures, multi-core wires experience severe surface oxidation, significantly reducing their effective cross-section. This can easily lead to problems like core breakage and localized overheating. If this occurs, it's recommended to replace the wire promptly for electrical safety reasons.
2. Regarding usage, is single-core or multi-core better for household wiring? There's no fixed rule; it depends on the specific application. For example, lighting wiring can always use 1.5mm single-strand copper wire. Air conditioners with a rating of 2P or higher, instant electric water heaters, and bathroom heaters must use 4mm double-strand copper wire. For other wiring, standard 2.5mm double-strand copper wire is sufficient.
RVV, VV, YJV, and KVV cables are all multi-core cables. Commonly used single-core and multi-core wires in homes today are generally copper conductors, offering excellent conductivity, low resistance, and superior electrical performance, making them more stable and reliable. Multi-core wires do have some advantages, but single-core and multi-core cables differ in their structures, each with its own distinct functions and advantages. Therefore, I will not specifically emphasize which one is the best here. I just hope that with the editor's knowledge, everyone can make some comparisons and buy the most suitable household wires.
