A generator or other source of current serves forsupply electrical appliances and mechanisms, so that, in turn, perform a certain work. A complete electrical circuit contains not only a power source and a load. An important element is the switching device. It carries out the inclusion of various loads in the chain. One such device is a packet-type switch.
What it is?
The device whose electrical solutionis implemented in such a way that it is possible to perform the function of connecting and disconnecting the load to a source of electrical energy, and also to carry out its redistribution, called a switch (switch). A batch switch is called because its operating elements are of a typical design, but they are assembled in one stack or a package.
The more number of elements of the scheme, the moreswitch position has a device. A switch with a number of switching positions greater than two is called a multi-position switch of the batch type. The devices-packers can work both with circuits of an alternating current, and schemes with a direct current.
Purpose of the switch
The permissible electrical parameters of the circuit, whereswitches and batch-type switches can work, this alternating current does not exceed 380 volts with a frequency of 50, 60 and 400 hertz, a constant current of 220 volts. The functions performed by the devices are as follows:
- As devices at the input of circuits (input commutators), which control electrical installations of power distribution.
- Switches with a manual mode of control in a situation where the connection and disconnection of the circuit will be infrequent.
- For the control of AC induction motors, when connected and disconnected by manual operation.
Circuit Breaker Assembly
Switches and switches, assembled by the type of packages, have in the design two basic units - a system of contacts and switching mechanics. The contact system includes:
- Insulating base having grooves in which the contacts are fixed.
- The contacts are fixed, equipped with threaded terminals for connection to the circuit.
- Screws for fixing wires.
- Contacts are movable, having a spring construction.
- Washers of spark extinguishing purpose.
The whole device can be assembled from differentthe number of individual sections that are mounted on a metal bracket with threaded studs. The bracket itself is provided with grooves. Due to them, the batch switch is mounted to the body or panel. Also, the installation can be carried out by means of upper brackets fixed to the body.
Contact groups of switches and switches of a package type are sliding. The contacts are fixed with each other under the action of the spring-loaded construction of the movable contact.
The mechanism that switches betweencontacts, is located in the cavity of the hardware cover. It is built in such a way that it provides instant switching, from which it follows that there is no dependence of the speed of movement of the contacts of the device on the speed of rotation of the handle.
The design of the switching mechanism comprises:
- The spring is clockwork.
- A handle on the shaft.
- Spring washer (stop).
- Protrusions for fixing the position when switching.
Packet-type switching devices havea clear fixation of the positions when turning the handle, which prevents spontaneous switching of modes and the hovering of contacts between the fixed plates. In this case, in normal operation, turning the handle, which does not exceed an angle of 45 degrees, should not lead to switching the position of the contacts, turning more than an angle of 120 degrees - allowing the change of the contact group.
Types of circuit breakers
Packets produce different models that differ from each other in the following ways:
- The location of the contacts, where external electrical wires are to be connected - from the rear, from the front.
- The number of switching positions is two for switches, up to twelve for multi-position switches.
- The level of protection from the harmful effects of the environment on the structural elements - open design, medium level of protection, watertight sealed.
- The constructive solution of the switching mechanism is the drum type of the switch, batch-cam.
- The method of attachment to the dashboard - the rear or front bracket, the front flange, behind the body in front or behind.
Symbol of package switchesdomestic production has an encoding consisting of letters and numbers: P X X-XXX XX XXXXX. The designation can be deciphered as follows, starting from the left to the right:
- П - a series of devices (batch);
- X - the letters B or P for switches and switches, respectively;
- X is the number of circuits that are available for switching;
- XXX is the rated current to which the device is designed at a nominal voltage of 220 volts, for example, a burst switch 16a;
- XX - number of directions when connecting electric lines;
- XX - type of performance according to climatic parameters;
- XXX - protection degree code for devices placed in a shell;
- X - method of fixing the package during installation.
- The constant current of the nominal value is the operating current that is allowed for the device to switch at a particular voltage value.
- The alternating current of the nominal value is the same, only for circuits of alternating electricity.
- The constant voltage of the rated value is the operating indicator of the amount of electricity allowed to withstand the insulating materials of the circuit-breaker.
- Variable voltage of the nominal value.
- Number of switching positions.
- Climatic performance.
- Degree of protection.
- The permissible switching frequency per unit time.
- Device resource.
How to connect the switch?
In addition to the case of the device, the packet switch is easily installed in the junction box to be connected to the network. For this you need:
- Disconnect the electricity and check its absence on the wires in the shield by the device.
- Determine if there is a loose DIN-rail in the box.
- Batch switch of the modern sample fasten directly to the rail with a latch. Devices of the old design are fastened to the rail using self-tapping screws.
- The ends of the wires of thin section are twisted into a loop and zaludit with solder.
- At the ends of the thick wires put on special tips.
- Wipe the device contacts from the protective grease with rags and connect the batch switch to the wires.
Each input terminal of the packerit is necessary at the same time to connect to the phase and zero wires coming from the electric meter. The output terminals of the breaker go to the input automata of the switchboard. When replacing the circuit breaker, first turn off the electricity on it.
Batch switches in switching devices have been used for decades. This is due to the presence of parameters that give them some advantages over other types of switches:
- The devices are compact in size, which makes it possible to position them even in small boxes and cases.
- Easy installation and replacement of the packet switch. Thanks to the brackets with mounting holes in the instrument panel, it is enough to drill similar holes and connect the elements with screws.
- Rapid extinction of the electric arc due to the original form of the movable contact and an additional spring, helping to quickly switch from position to position.
- Not labor-intensive maintenance, caused by a successful design solution, which allows simply to replace the failed modules with new ones.
- Durability. All elements of the circuit breaker are made of materials that withstand long mechanical loads in terms of switching and vibrations.
- A wide field of use of devices due to a large selection of switches according to technical parameters and climate performance.