Packet switch - a device for switching, typically up to 1 kV circuits consisting of separate sections - one for each phase. What determines the particular burning and extinguishing the arc at the time of the change of the position of the contacts. Sellers often referred to as such changeover switches, the outputs are switched (thrown) in turn.
marking
Marking includes a variety of information, rigid standards is not established (anyone acquainted with GOST P 50030.3). Each manufacturer's own rules, there is an example in the range of industrial association of electrical engineering, whose switch is depicted in the photographs.
According to GOST 50030.3 to the housing bear a manufacturer's name or trade mark. In the above case, the inscription of electrical engineering. Decoding and identification of the product begins with the key letters (PP or PV), showing the actual product. Then tabulated number of poles and operating current to voltage 220 for both families of B. In addition to climatic conditions by GOST 15150 switches characterized by starting the engine parameters. The photo shows the product that is designed for switching on the two areas (Package).
For proper placement of the equipment is sure to specify the type of protection of housing IP class. This makes it possible to meet the requirements of GOST and industry standards for equipment specific object space. Presented at the photo switch is indicated by the designations can not be held for a simple reason: the body protection is not available, contact the product are exposed to the outside. Degree of protection IP00 housing.
design Features
In batch execution occur breakers and switches. First open or close contacts. The second phase allows to flip from one branch circuit to another that is used, for example, for manual starting of asynchronous motors. The difference is in the speed of response. In the case of an induction motor should have time to throw the food, while the shaft is not lost speed.
The difference between the conventional product groups:
- Packet switch carries two contacts which are opened or closed, depending on what position is rigidly predetermined shaft.
- Packet switch throws circuit output from one position to another and for this reason finds at least three contacts. One common (Common). Present position "off" when the phase is not output (pin closes on itself).
In any design of the shaft locking mechanism is present to discharge the charges from such contact groups. This feature becomes uniting two families, along with the presence of isolated small and limited volume of the closed package. Each package consists of movable and fixed contacts of different shapes, closed in a fiber cheek. The volume is bounded on all sides by walls of the housing that facilitates rapid quenching of the arc.
It is important to take into account before you buy housing material. Karbolit presented in the photo, is not amenable to repair, easily beating. When danger strikes it is better to take a less durable plastic. To ensure the two factors (a considerable period of service in conjunction with impact protection) often suitable silumin.
Details better to check with the manufacturer. To join Electrician phone 88,002,503,027. Free in Russia.
Changeover packet switch
Packages of cylindrical shape, arranged one above the other. Every single phase, which is thrown to the outputs in turn. Accordingly, there are three positions:
- OFF (0).
- Output 1 (I).
- Yield 2 (II).
Lock handle in the end positions is carried out by two studs located on a white ground, directly under the switch cover. The axis is equipped with a rigidly fixed hammer, armed challenge restrictions in movement. The second responsibility of this curious form part becomes latch control: at every position the handle is held stable through said part.
When you try to rotate the hammer axis assigns brace themselves. At the same time the springs. Sides hammer angular shape in the trough bracket catches and goes in a circle. Hull form is that as we approach the next position pressing weakens. As a result, the bracket, extruded spring, stands firmly on its new position. As shown in the photo packet switch fixed positions - as already mentioned - three. Considered design is not the only one on the market. Positions there are sometimes more.
The packages are secured long bolts. Each chamber consists of fixed contacts and movable (rocker). In the off-state neutral contact is closed on itself. Its shape is different from others and looks sickle. Each contact is freely walking inside fibric cheeks, reminiscent of the pulley drive with a thin groove. This detail is needed to extinguish the arc. Mechanism:
- When opening the knife contact ionized air. Arc flashes.
- The spring pushes the fast axis in the direction to the next position, which dramatically increases the flame length. The stream of ionized particles breaks down.
- Simultaneously, heating of the spark gap leads to the release of expanded gas from the pores fibric cheeks. This pressure rises sharply reduced velocity of the ions and violated their direction of travel. The further conditions for extinguishing the flame.
Knife electrical contacts are made of bronze. Option is taken because of the durability, in contrast to flat. Contacts are able to rotate in a circle, without limitation, excessive force applied to the handle, only manages to break the plastic spikes. What directly follows the statement: provornuty forcibly packet switch easily amenable to repair by welding. Drive spiked deliberately made of white plastic to enhance the elastic properties, in contrast to the rest of the body made of karbolit.
Hammer hits the limiter without breaking. The increased durability of the product, it is possible to repair. A major limitation of the packet switch considered switching speed, measured in times per second (minute, hour, and so on.). Limit physical properties due spring latching mechanism. Each position is signed, do not try to go beyond the bounds of the angle of rotation.
Housing packet switch designs presented necessarily grounded (for three-phase network - vanishes) - the transition time of each packet contains the arc. If at this time accidentally touch the metal, it is easy to get a severe blow, even in the absence of grounding other parts of the body. Due to the presence of the body's own capacity, rechargeable from the burning arc.
The packages are not sealed, increasing the pressure of ions occurs so rapidly that small gap does not have time to have an impact and prevent the normal process of extinguishing the arc. In this model, the label marked phase entry position (L1 and L2, from the English. Line) and neutral (C, from the English. Common). There have been two characteristics of the product described like minor shortcomings:
- Stickers gradually come off easily. Their mission - to give the installer to figure out how to carry out commutation wiring. When operating the stickers will inevitably disappear.
- According to the rules for electrical wiring (see. PUE) phase is applied to the switch, and consumers - neutral. It breaks the tension but not neutral, it is easy to think of the label layout. It relies on the total feed phase (which is in conflict with sticker), and the load connected to two other terminals (and it will work alternately).
Cam packet switches (PCI)
The figure from the book Chunikhina AA It is given in the context of a single package. Three groups of contacts can be powered from a single phase or from the three. The design is considered more reliable than those described above. Due to wear of mechanical parts.
Figure cam device
The cam is shaped so that at the initial moment of switching resists the movement of the operator. As spring charging camber changes, the axis now aims to take a new position. With the click of a rod pushes the spring, closing the two pairs of contacts. Splitting roof halves facilitates its rapid quenching.
The retainer is normally equipped with a gear next to the recesses in the number of fixed positions. The locking mechanism of the shaft provides stability in a particular position. Single cam shaft deflection under the movable contact group for this purpose is not enough. Packages up to 8 times, each with a number of groups of contacts.
Parameters packet switches
Contradictions with stickers provided by the relational model. In the case indicated that the product is working in circuit 380 V. If there is no neutral on all findings will be submitted phase, regardless of the written material. In this context, stickers do not report useful information. Successful markings instead (the first phase) 1L1 and 2L1 would be put down icon neutral (N) or the ground, getting the type designation 1N1 and 2N1. It would be understood that one common contact, here served phase, and the two points - a neutral circuit with enabled to load for the networks 220 or another phase for 380 V.
If you change the output voltage remains constant. The main body of said packet switch it is said that it is suitable for operation at a voltage of 220 V with a current of 16 A or 380 V and 10 A. Multiplying the numbers in pairs, we get 3.5 and 3.8 kW. The results are not equal to each other but of the same order and are approximately the same. The explanation is simple - the current values are selected from a standard range, which includes values 10 and 16 A. This is required in order to properly combine the equipment and circuit breakers, which are produced under the standard ratings.
Of course, the operating currents are taken into account and the section wiring cores. It is understood talks about this in the videos notorious A. Zemskov (on own channel). Thus PP2-16 / H2 packet switch is designed to power 3.5 kW. Exceeding this value will result in overheating of the contacts and the arc will damage bonus product.
Said packet switch for outdoor installation is not intended, it clamps are not protected from the environment.
In addition to the switching frequency factor present time limit. According to Russian norm identify several modes of operation of electrical equipment. The most intense is considered long. This is what is expected from the batch switch customers - continuous operation of an arbitrarily long time.
An important parameter is recognized as maintainability. It is no secret that in the production of the impact and other damaging factors. In this case, the body of karbolit not always become the best solution. The plastic is easily repaired by welding and has good elasticity, which reduces the risks.
