[Automatic Control School] Weak Current Engineering Series: Introduction to Commonly Used Cables

There are many types of wires used in weak current engineering. Here are a few commonly used ones. Everyone can find out

CATV cable:75 ohm solid core polyethylene insulation

Generally speaking, the most common type in Taiwanese residences is the Japanese 5C-2V specification.

5C-2V (RG-58U) use place:Floor or interior part of the house

7C-2V (RG-11U) use place,Building backbone wiring

4C-2V (RG-6U) use place,Satellite Antenna Wiring

Types of weak power cords

Summarize the knowledge of weak current cable. Today, let's learn about the commonly used weak current system cables. Power cord: It is a wire that transmits current and consists of an outer sheath, an inner sheath, and copper wires.

BV, BVR, RV are all single-core wires

BV: Copper core PVC insulated wire is a single core wire of copper wire, which is relatively hard, also called hard wire.

BVR: Copper core PVC insulated flexible wire is a single core wire with multiple strands of copper wires twisted together, also called a flexible wire.

RV: Copper core PVC insulated connection flexible wire is a single core wire with more than 30 copper wires twisted together, which is softer than BVR.

BVVB: Copper core PVC insulated PVC sheathed flat wire, is a hard sheathed wire, that is, 2 or 3 BV wires are sheathed together.

RVV: Copper core PVC insulated PVC sheathed flexible wire, commonly known as soft sheathed wire, that is, 2, 3 or 4 RV wires are sheathed together.

Summary: You may have discovered that most of these letters are the first letters of Pinyin. Knowing the meaning of each letter and combining the names, it is easy to guess.

1. RVV

The full name is copper core PVC insulated PVC sheathed flexible cable. The RVV cable is round in appearance, has a large number of cores, and is stranded between the two cores. R stands for flexible cord, and the letter V stands for insulator polyvinyl chloride (PVC). The main purpose of RVV cable: used in electrical appliances, instrumentation and electronic equipment and automation devices and other power lines, control lines and signal transmission lines that do not require shielding.

Commonly used RVV wire models are: RVV2*0.5, RVV2*0.75, RVV2*1.0, such as: RVV2*1.5 - 2 means 2 wire cores, 1.5 means the cross-sectional area of one wire core (unit is mm²)

2. RVVP

The full name is copper core PVC insulated PVC shielded flexible cable. It is suitable for communication, audio, broadcasting, audio system, anti-theft alarm system, intelligent automation system, automatic meter reading system, fire protection system, etc. The letter R stands for flexible wire, the letter V stands for insulator polyvinyl chloride (PVC), and the letter P stands for shielding. RVVP can be used for control lines in monitoring systems, access control systems, building video intercom systems, and building control systems.

The difference between RVV and RVVP:

RVVPCompare RVVAn extra layer of shielding braid, the RVVP wire has a layer between the inner and outer sheathsThe meshed copper wire layer acts as a shield-—

-The shielding layer is mainly to prevent the influence of the external electromagnetic field to improve the anti-interference balance of the wire.

3.AVVR cable

The full name is copper core PVC insulated PVC sheathed flexible cable for installation. Usually used for weak current power supply.

The difference between RVV and AVVR:

AVVR and RVV are the same cable. Models above 0.5 square meters are classified as RVV (including 0.5 square meters) and models below 0.5 square meters are classified as AVVR.

4. BV

The full name is copper core PVC insulated wire, and BV wire is also referred to as plastic copper wire, where B stands for category, belonging to cloth wire, V stands for PVC insulation, generally suitable for electrical instrumentation equipment and power with AC voltage of 450/750V and below The supply of electricity for lighting, fixed wiring, etc.

BV line is divided into: ZR-BV and NH-BV

1) ZR-BV: Copper core PVC insulated flame retardant wire: The insulating material is added with flame retardant, and it will not spontaneously ignite when left open fire. The flame retardant BV wire is divided into four grades: A, B, C, and D. Among them, A is the best, and so on. The most commonly used is ZB-BV.

2) NH-BV: copper core PVC insulated fire-resistant wire: it can be used normally under normal fire conditions.

It can guarantee 1 hour of uninterrupted power supply in the flame burning, can still keep the circuit unobstructed, will not be short-circuited for a certain period of time, and have fire resistance requirements

5. BVR

The full name is BVR PVC insulated flexible wire. BVR wire, generally refers to BVR power cord, is a copper core PVC insulated flexible wire, which is used in the occasions where flexibility is required for fixed wiring. B means it is classified as a cloth wire, V means PVC polyvinyl chloride, also commonly known as "plastic", R means soft, to be soft, it is necessary to increase the number of conductors.

BVR wires are also divided into flame-retardant wires (ZR-BVR), fire-resistant wires (NH-BVR), and low-smoke halogen-free wires (WDZ-BVR) according to the different materials used. Mainly used for electrical instrumentation equipment and power lighting fixed wiring.

The difference between BV and BVR:

a. In terms of production process, BV is single-core and BVR is multi-core. In production, BVR is a little more complicated than BV.

b. In terms of price, BV and BVR are a little more expensive than BV because they are only in the process.

c. In terms of performance, BV is basically the same as BVR, and BVR is slightly heavier in weight.

6. RVB

RVB is a flat unsheathed cord, commonly known as red and black (parallel) lines. It is suitable for household appliances, small power tools, instruments, meters and power lighting to connect electricity.

7. RVVB

RVVB is a flat sheathed cord, RVVB and RVB have the same purpose, the difference is that RVB is a flat unsheathed cord, while RVVB is a flat sheathed cord, so RVVB has an extra layer of sheath than RVB.

8. RVS

The full name of RVS wire: copper core PVC insulated stranded flexible wire for connection, twisted multi-strand flexible wire, referred to as twisted pair, commonly known as "flower wire", at this stage, this kind of wire is mostly used in fire fighting systems, also called "fire wire" . The letter S stands for twisted pair, the letter R stands for flexible wire, and the letter V stands for polyvinyl chloride (insulator).

The use of RVS twisted pair:

1. Mostly used for the detector circuit of fire automatic alarm system

2. Suitable for household appliances, small power tools, instruments and power lighting lines. The double-white core is used to directly connect the lamp head line; the red and blue core is used for fire protection, alarm, etc.; the red and white core is used for broadcasting and telephone lines; the red and black core is used for broadcasting line.

3. It is used to connect the power amplifier with audio equipment and broadcasting system to transmit the audio signal amplified by the power amplifier.

The difference between RVS and RVB is:RVB is parallel cord, RVS is twisted pair cord