Batch switch: what is it and why is it needed + wiring diagram
It is unlikely that there will be a mature person who would not have seen a packet switch in his life, although not everyone knows what it is called. Several decades ago, such devices were installed in every entrance and in all apartments.
They were used as circuit breakers, with the help of which the power supply was turned on and off. Over time, the bags were replaced by modern machines, but not everywhere.
The content of the article:
- What is a packet switch?
- Design features of the bag
- 5 indisputable advantages of devices
- The main types and types of bags
- More modern analogues of the device
- Packet connection diagram
- Conclusions and useful video on the topic
What is a packet switch?
Packets are devices designed for switching (i.e. turning on and off) small load currents. They are connected to electric networks of direct and alternating current 440-660 V.
The devices can hardly be called convenient, since their device does not provide automatic power-off systems in case of overloads.
In addition to the lack of protective automation, devices have another significant drawback: they break quickly with frequent voltage drops. For this reason, they began to be used much less frequently.
But still it’s too early to talk about the irrelevance of the packets, while they are cheap, and their switching resource is satisfactory. Devices are still convenient for use in distribution boards and control panels.
At the entrances of high-rise buildings, package switches have not been installed for a long time. They were replaced by modern two-pole machines, which are distinguished by better wear resistance, durability and greater current carrying capacity.New appliances are connected to the power grid of each individual apartment, not the entrance.
Design features of the bag
The design of the bag includes a contact group and a switching mechanism. They are enclosed in a shell, where there are also movable contacts fixed on a square sleeve made of insulating material.
The device is equipped with fixed contacts, the terminals of which come out of the case and resemble knives in their shape. The contacts are connected and disconnected using a spring. It is controlled by means of a knife switch.
The rotation of the handle leads the spring of the switching mechanism. She turns a figured washer and movable contacts a quarter of a turn. The stroke of the washer is limited by the stop located in the cover.
The movable contacts are attached to plates made of fiber. The material, when heated, releases gas, which moves under pressure through the openings of the bag. Instead of gas, non-ionized air enters the casing and extinguishes the arc.
Due to the simplicity of design and ease of use, the bags are widely used in the following areas:
- as input switches;
- to switch control circuits;
- as electric current distributors;
- for controlling electric motors.
There are many different types of models designed for use in different conditions: in dry and wet rooms, for installation in panels and technological niches.
5 indisputable advantages of devices
The popularity of package switches for many decades is due to the indisputable advantages of these devices:
- Compactness. Due to their small size, the devices are easy to install and convenient to operate.
- High arc extinction rate. Batch switches are rationally designed, therefore, both the extinction of the electric arc and the shutdown of the device occur almost instantly.
- Ease of maintenance. Sachets do not need any special care or maintenance. The main thing is that they be inspected on time and replaced if necessary.
- Resistant to damage. Devices are hard to break. They cope well with mechanical stress, do not suffer from vibration.
- A wide range of applications. Batch switches are not afraid of high and low temperatures (from -40 to 70 degrees). Devices enclosed in sealed enclosures are resistant to dust and moisture.
The life of the bag directly depends on the condition of the protrusions of the fixing washer.
If the main working part wears out, the device fails. It is because of this feature that there are complaints about the devices regarding their short service life.
Batch switches cannot be repaired. If they break, they have to be replaced. But during the entire period of operation, the devices do not need to be serviced. It is enough to clean them from contamination every six months and check the functionality.
The main types and types of bags
Sachets are classified according to various criteria:
- at the place of connection of external electric cables to the panel (front, rear connection);
- by the degree of protection of internal structural elements from negative environmental factors (distinguish between open, protected, sealed devices);
- by design features of switches (packet-cam, drum).
Despite the wide variety of package switches and switches, they have common technical and operational characteristics and similar disadvantages.
So, the resource of the spring mechanism is designed for approximately 103 power outages. There are wear-resistant models that perform 203-1000 shutdowns. The main condition: the frequency of operation of the mechanism should not exceed 50 within 1 hour.
Product labeling may include the following alphanumeric symbols:
- "B" - switch;
- "P" - switch;
- "P" - batch;
- "G" - tight;
- digits 1-4 - the number of poles;
- “N” - direction (2, 3, 4, as well as “P” - reverse).
In the labeling of devices indicate the degree of protection, type of placement, installation features, rated current. Sometimes you can see notes, reductions in "strength." and "pl.".
They are used to indicate the material of the body (silumin, plastic). For example, the marking of the GPPM-2-60 / H2 device is deciphered as a 2-pole 60-amp sealed packet switch in 2 directions.
More modern analogues of the device
Old batch switches almost everywhere were replaced by machines. This is logical, because the requirements for energy consumption and durability of devices have changed. Nowadays, RCDs (residual current circuit breakers), automatic and differential machines, contactors are widely used.
Option # 1: residual current device
The device is designed to prevent current leakage. It reacts to a differential current, which contributes to the overheating of electrical cables, which can lead to a short circuit, fire of the wiring. Also, leaks can cause electric shock.
RCDs must be installed in order to avoid the risk of electric current leakage if it begins to pass by consumer devices.The device acts as a leak indicator, which simply turns off the electricity in the event of a malfunction.
On its own residual current device Does not protect against overload or short circuit. This is only possible if connected in combination with a circuit breaker.
Option # 2: Circuit Breaker
These devices were replaced by a batch switch. They perform the same functions, but are more convenient in operation, durable and wear-resistant.
Circuit breakers can also be one-, two-, three-, four-pole. They differ in the type of drive (it can be manual, spring, motor), the type of connection and other technical and operational characteristics.
Offered for sale circuit breakers label and classified in accordance with GOST 9098–78 and 14255. These documents establish the requirements for the technical characteristics of the devices.
Option # 3: differential automaton
This is a combined machine that simultaneously performs the functions of two devices - an RCD and a circuit breaker. Differential machine perfectly replaces the bag, suitable for household electrical networks and successfully used in enterprises.
Functional and constructive differences between a differential automat and RCD given hereWe recommend that you familiarize yourself with very useful information.
The differential machine prevents leakage, short circuits, minimizes the risks of electric shock. The design of the device includes thermal and electromagnetic releases. The first prevents overloads in the network, and the second is needed to turn off the electric current during a short circuit.
Option # 4: contactor - type of electromagnetic relay
The device is necessary for remote control of the on / off modes of electrical circuits. Electromagnetic relays they do not work with a short circuit and are designed only for rated currents. This is their main difference from circuit breakers.
In modern residential buildings, obsolete package switches are rarely installed. Practically universally practiced installation of difavtomatov or RCD connection in combination with a circuit breaker. But there are cases when a good old bag can be indispensable, for example, if you need to turn off the current supply during electrical work.
Packet connection diagram
Thanks to its compactness, the packet switch can be installed in the panel. To do this, use a din rail. If you select an old model, you need to consider that it is unlikely to have a latch on it, and self-tapping screws will be required for installation. There are no problems when installing modern packages.
Two input terminals of the bag connect to the phase and zero wires that come from the meter. And the output terminals are connected to the machines in the shield.
On domestic circuits, the wires of zero and phase are indicated by blue and red colors, respectively.
If the product is imported, then the colors of the cables may be different, so be sure to read the technical documentation and manufacturer's recommendations.Do not experiment blindly.
Conclusions and useful video on the topic
We offer thematic video compilation, which will help to understand the design, purpose, principle of operation of packet switches of various types.
Design features of the Soviet batch switch:
Modern models of the CA25 series:
How is the PVM 2 10 bag:
Video instruction for connecting an RCD and a circuit breaker:
Although the popularity of batch switches is decreasing every year, manufacturers continue to produce them. New models are much more convenient and have fewer disadvantages than outdated ones.
When choosing a suitable bag you should pay attention to several brands: Legrand (France), Iek (Russia), ABB (Sweden, Switzerland). These are reliable brands, and their products are of high quality.
Tell us how you chose or installed a batch disconnect device with your own hands. Share technological nuances that will be useful to site visitors. Please ask questions, post a photo on the topic of the article, leave comments in the block below.