An obsolete analogue of a circuit breaker is the so-called bagger. Previously, this device was often used to distribute electricity, and in particular to completely cut off electricity in an apartment. Due to its fragility (it burns out during voltage drops), it has become less and less used for domestic needs, however, for industrial purposes, the use of a bag is quite relevant. In this article, we will look at the device, purpose and principle of operation of the burst switch.
Content:
- Design
- Operating principle
- Appointment
- Application area
Design
This unit got its name because of the peculiarity of its design. Switching elements of the same type are assembled on one axis and constitute a single device. The picture below shows the design of the burst type disc switch.
The casing is made of electrical insulating material, with grooves for fixed electrical contacts, and is equipped with arc extinguishing chambers. In the center there is a movable washer made of insulating material, with electrodes located on it. Several of these elements are located on one axis, with the help of which the apparatus is driven.
The figure below shows another type of packet switches - a cam, or as it is also called, a biscuit. Electrical insulating body with fixed and movable contacts located on it, supported by springs and located on guide insulators, which abut against a movable figured washer, with recesses for the guides pins.
You can learn more about the device of the bagger from this video:
Operating principle
Let's take a look at how a packet switch works. So, the operator, turning the handle, activates the movable washers. They, in turn, transmit movement to the contact group, as a result of which switching occurs, the contacts open or close, depending on the initial position.
Disk packaged switches have two switch positions: on and off. Cam switch it is possible to "program" and the switching of contacts will depend on the position of the switch itself.
Appointment
Load switch - it is also a disk switch, due to the simultaneous operation of recruited in one case switches are often used as a power element to disconnect the load, electrical machines, power chains. Also, the bag is needed to switch the load from one supply circuit to another (emergency reserve input).
The cam bag is used as a control switch for the operating circuits. It supplies power to the control circuits depending on the position of the switch, turning the controls on and off.
Application area
The picture shows the main types of burst switches:
You may have seen them in electrical boxes and driveways (load break switches). Some models are equipped with transparent viewing windows for visual observation of the state of the contacts, which allows you to make sure that the device is in the correct position. Packets are used in control panels, operational switching, in substations for taking readings of values from a remote line, operational personnel. In addition, packet switches are used in the cabs of operators of electric power units: cranes, excavators and other mechanisms.
With this switch, the driver sets the speed and direction of rotation of the power unit, selects the operating mode, by closing the group of contacts responsible for this parameter, the section schemes.
Often on linear diagrams of mechanisms, you can see such a designation - a command controller. This is the position of a group of contacts in a batch switch, for controlling mechanisms by feeding in a certain order to the power control circuit. For clarity of work, we will analyze the control circuit of a two-speed electric motor.
The picture shows part of the switching circuit of the star-delta motor windings. Cam switch - command controller, marked with the letters SM. In position 1, power is supplied to the circuit, the KV relay becomes self-locking, supplying power to the operating circuits, regardless of the location of the controller key. In position 2, the KM1 starter is fed to the coil, which starts the engine in a triangle pattern. When the device is switched to position 3, the coil of the KM1 starter is de-energized and fed to the KM2 and KM3 starters, which connect the motor to the network according to the double star scheme.
We have considered more detailed reviews of starters and control methods in our other articles. Now you probably know more about the purpose, principle of operation and the device of the burst switch!
It will be helpful to read:
- Types of relay protection
- How to connect a thermal relay
- Phase sequence check
