Difference between RVV and RVVP of building control aspect

A suitable for transmission of control signal, a suitable for the power cord details are as follows:
RVVP: copper core PVC insulated shield PVC sheathed flexible cable voltage 300 v / 300 v 2-24 core
Purpose: the equipment, instrumentation, intercom, monitoring, control, installation
RG: physical foaming polyethylene insulation access network cable Used for coaxial optical fiber hybrid network (HFC) analog signal transmission of data
UTP: LAN cable USES: telephone, computer data, fire prevention, anti-theft security systems, intelligent building information network
KVVP: PVC sheathed braiding screened cable USES: electrical appliances, instrumentation, power distribution equipment, control, measurement of signal transmission
SYWV (Y), SYKV cable TV, broadband network structure of special cable (coaxial cable) single round copper wire for anaerobic + physical foaming polyethylene (insulation) + (tin) + aluminum + PVC (PE)
RVV (53) 227 iec52 / PVC insulated flexible cable USES: home appliances, small electric tools, instruments and dynamic lighting
AVVR PVC sheathed bx cable
SBVV manufacuring HYA data communication cable (indoor and outdoor) used for telephone communications and radio equipment of the cable box terminal connection and telephone wiring network
The RV, RVP PVC insulated cables
RVS, RVB is suitable for household appliance, small electric tools, instruments, meters and dynamic lighting connection with cable
BV BVR, PVC insulated cable USES: used in electrical instrumentation equipment and lighting fixed wiring in power
RIB speaker cables

KVV PVC insulated control cable application: electronics, instruments, power distribution equipment, signal transmission, control and measurement
SFTP telephone twisted-pair cable transmission network, data and information
UL2464 computer cables
VGA display line
SYV coaxial cable of the wireless communication, broadcasting, monitoring and control system engineering and related electronic equipment in the rf signal transmission (including integrated with coaxial cable)
SDFAVP, SDFAVVP, SYFPY coaxial cable, elevator
JVPV, JVPVP, JVVP copper core PVC insulated and sheathed wire weaving computer control cable

Imported 500kv dry-type cable expert advice

Countries such as America, Japan, Italy, the home is crosslinked polyethylene flexible cable production, after crosslinking cable temperature can reach 90 ℃, transmission capacity increased a lot.But in a high degree of purification of polyethylene material must be added crosslinking agent, etc., affect the insulation performance.
1. the French sole advocate using low density polyethylene insulated cable, up to 400 kv voltage level, to meet the requirements of the order, has already produced 500 kv cable.The cable without crosslinking, although the highest operating temperature is 70 ℃, but guarantee the insulation with high purity, excellent electrical properties, both strengths, but also complement each other. Below level
2. the French think 200 kv power cable using crosslinked type is advisable.But still adhere to a higher voltage grades of cable claims with low density polyethylene insulation, because it has excellent electrical performance.At the same time, foreign experts have suggested that the crosslinking cable temperature drop down, down to 80 ℃, for the directly buried underground.So the differences of the two, gradually shrinking.In this case, we believe that imports which kind of cable can be in the future.

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Wire and cable fault side search method

The first thing to determine the fault types: "high impedance" or "low resistance" We're going to do different according to different fault types of fault location method. How to distinguish the high rent or a low resistance?Insulation resistance.High resistance and low resistance wire and cable without a very clear definition of value, usually 100 k under the considered low resistance, more than 100 k o considered high resistance.

Book a fault We according to the different fault types, using different methods to due to a fault, first of all get the approximate location of fault point.

Then we'll point fault accurately Before the precise point, we also need to know the detailed information of the fault cable laying we won't be able to arrive according to the value of preoperative near point of failure.If there is this kind of situation, we need to use beforehand "path" to determine the path of the cable, use range to determine the approximate location of the fault point.And then to be able to accurately fixed point.

If it is a high impedance fault, we should use "shock" to accurately fixed point, first by a high voltage pulse generator, at a certain time interval to shoot fault cable, high voltage pulse and fault point will be breakdown and continuous discharge.We by detecting the fault point discharge signals for accurate positioning.At this time we need a "precision" designated instrument, its principle is "magnetic acoustic time difference method", precisely: at the time of discharge cable is two signals, one is the electromagnetic signal, a signal is the sound of the discharge.Two signals from the point of failure due to the different velocity of propagation, reaches the receiver when there is a "time lag", like thunder when we see the lighting first and then hear the sound, we can accurately by judging the "time lag" positioning fault - lag the smallest place point of failure.

If it is a low resistance fault, we all know that low resistance grounding fault failure and even death, because of the low to ground resistance, discharge could not make it happen, we need the other way - "audio method".Using a powerful audio generator fault cable to a fixed frequency audio signal, and then use audio detector along the cable route.Due to very low resistance at fault point, the signal current will be here into the earth, look from the detector, reach the point of failure, the signal can suddenly become very small or even disappear.At this point we can locate the fault point.

At this time we can excavation flexible cables, dig the cable, after cutting to do joint fault section, do the pressure test, all OK, put into operation. But need clear confirmation when truncation cable fault cable, if errors occur, the consequences.

Aluminum stranded conductor dc resistance measurement method

For aluminum stranded conductor dc resistance measurement, many companies have also made a lot of research.In GB3048, the resistance when measuring the voltage and current of the distance, measure the current size and so on all the rules.Qualified for single use normal process of stranded wire core, still have to discuss problems in actual measurement, such as potential end shape on the measurement results, the influence of four-terminal method of resistance measurement of key points and how to realize the measurement of current uniform, etc.
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1.Twisted wire core insulation, the single wire in the electric current is along a single line into spiral flow, and the whole single wire line core reliably with the current introduction.Calculation of 1 m long stranded wire length of each layer, according to the formula of parallel resistance, dc resistance formula for computing the stranded wire, such as:

Actual twisted wire core still exist certain conductance between single wire, the size of the conductance associated with monofilament surface conditions.Conductivity is made with dc of wire core in completely along the single spiral flow, is part of the current along the monofilament into axial flow.The wire core dc resistance than current along the monofilament completely into smaller spiral flow.Because after stranded aluminium resistance of single wire has no obvious change, under the single qualified, even after considering the wire core cable length increased by 1%, twisted wire core resistance still has a certain margin.

2. The reasons of the measured values are not qualified
In the winding resistance is unqualified phenomenon, the reason is the resistance measurement to measure current not evenly through the sample.
All the monofilament wire core reliably with the current introduced, and the monofilament wire core insulation current flows along the monofilament into a spiral.So in the case of monofilament diameter is the same, homogeneous structure, cross section perpendicular to the line on the flexible cables core sample should the equipotential surface, in the cross section of potential difference between the monofilament is zero.In allelic case, voltage potential difference between side won't because of the shape of the voltage clamp, and ways of contact with the sample and the sample of the clamping force changes in the surface changes.

Measuring the winding resistance of fixture shapes are now a knife shape and round shape, by tightening bolts pressure on sample.As a result of the existence of monofilament aluminum surface oxidation film, when when the measured current is introduced through this form jig sample, its current points Cloth is often uneven, the winding outer filament current density.The phenomenon is serious with the increase of stranded wire section.

V current fixture than the sword shape, round ring current clamp has greatly improved, but still cannot make current to achieve the ideal state of uniform. Uneven distribution of the measured current to make 1 m away from the two voltage is the voltage difference, is greater than the uniform measure electricity shed the voltage difference between the two voltage side.In this case, the voltage terminal fixture shapes, also often cannot work pressure for further improvement.Therefore, the key is how to measure to solve the problem of resistance measurement of uniform current and voltage clamp requirement, can make the measuring current is measured and the necessary.

Wire and Cable Industry in China

Wire and cable industry is the second large industry next to the automotive industry in China. Fill Rate of products and occupancy of domestic market both over 90%. Worldwide, wire and cable gross output in China has been more than the United States, become the first major producer of wire and cable in the world. With the high-speed development of wire and cable industry of China, the number of new companies is rising continuously, overall technical level of the industry is increased sharply.

The development of Wire and cable industry, national economy and the automobile industry, shipping industry are closely related, even in a certain time, to a certain extent, the development of wire and cable industry represents the degree of a country national economy development.

Sustained Rapid economic growth of China provides a huge market space for wire products. The strong allure of China made the world focused on the Chinese market. In short decades from reform and opening-up, the huge production capacity formed by the cable manufacturing of China Knock the Socks off the world.

Anytekabel Co.,Ltd. in China, Changzhou is also in rapid development in recent years. We apply with the design concept of advanced precise cable manufacturing technology and mature production of German, cooperate with German cable company with technical, guided by the needs of customers, develop into a high-tech cable company combined of R&D, production, sales and service.

Introduction to irradiation and silane crosslinking cable difference

Customer orders are sometimes encountered model for WDZ - YJ (F) E flexible cables, this kind of cable should be interpreted as the name of the copper core irradiation crosslinking polyethylene insulation, low smoke zero halogen flame retardant polyolefin sheathed power cable, power cable product standards GB/T 12706.1 ~ 3-2008 of the rated voltage 1 kV to 35 kV (Um = 1.2 kV) = 40.5 kV (Um) squeeze, insulated power cables and accessories, the first part of appendix D "the cable products of the clause," said about insulation code method, for crosslinked polyethylene insulation, code-named YJ, did not distinguish between what crosslinking type (physical or chemical), belongs to physical crosslinking type irradiation crosslinking, and combined with "F" in the model, the industry said an idiomatic irradiation crosslinking insulation methods.Standards should be still for GB/T 12706-12706.

Customers use this model to use irradiation crosslinking insulation wire core to meet the requirements of the use of the special occasions.The irradiation crosslinking and ordinary silane insulation what are the advantages?Irradiation crosslinking is using high energy electron beam produced by the electron accelerator to the crosslinking of cable, the cable insulation layer of polyethylene structure.

By linear molecules into a three-dimensional network structure, formed less than the three dimensional lattice water molecules, the polyethylene surface and internal form dense layer, thus effectively prevent the hydroxyl and the combination of water molecules, the crosslinking method not only improves the heat resistance, abrasion resistance and flame retardant performance of wire and cable, of the block water. The crosslinking way no heat, no water, can make PE crosslinking, and can improve the flame retardant and electrical cable wire performance of cable.Make the cable has low smoke, halogen-free, flame retardant and high temperature resistant characteristics.

Fire-resistant cables for security alarm

The field repair of the cable also must be prepared to some of the tools and materials used fully, plastic welding torch is essential, high-voltage insulating tape, waterproof tape and plastic insulated and sheathed strip cut leather, such as sealing material, must also be prepared, because the cable insulation sheath material is mainly divided into crosslinked polyethylene, polyethylene, PVC etc. Some materials belong to thermosetting materials, such as crosslinking polyethylene insulation can't repeat the molten again use, use of raw materials for repairing in site, can only use high voltage insulation tape and repair in United States 3 m tape series for repair. And some of the material belongs to thermoplastic material, can again with high temperature, fused using such as polyethylene, PVC and other materials, can live out, using the cable ends covering materials for cutting down the edges of cut into thin strips, can realize the low voltage cable insulation and sheath repair, the repair quality can fully meet the cable normal use performance requirements.

Another for medium voltage Security cables cable sheath damage phenomenon during the processing, cannot too rough, a process is the installation of the cable must be a light to put, please again after a cable appear external damage, its internal insulation damage sometimes is to say, the author used on construction site installation process accidentally damage to large area of outer sheath of the cable, and with returned to the factory, found that the partial discharge of cable damage levels and breakdown phenomenon, so for medium voltage power cable laying process appeared at the scene of outer sheath after damage, it is best to truncate or to replace the cable intermediate joint, because after the sheath of cable damage repair, there may be using.