Batch switch: what it is and what you need + wiring diagram
There is hardly a mature man who would not see a packet switch in his life, although not everyone knows what he is called. Several decades ago, such devices were installed in every staircase and in all apartments.
They were used as switches, with which they turned on and turned off the power supply. Over time, the bags were replaced with modern machines, but not everywhere.
What is a packet switch?
Packet bags are devices intended for switching (i.e. switching on and off) small load currents. They are connected to the mains DC and AC 440-660 V.
Devices can hardly be called convenient, because their device does not provide for automatic de-energizing in case of overloads.
In addition to the lack of protective automation, devices have another major drawback: they quickly break with frequent voltage drops. For this reason, they began to be used much less frequently. Still, it is too early to talk about the outdated packers, while they are cheap, and their switching resource is satisfactory. Devices are still suitable for use in distribution boards and control panels.
In the entrances of high-rise buildings, packet switches have not been installed for a long time. They were replaced by modern bipolar machines, characterized by better durability, durability and greater current carrying capacity. New appliances are connected to the electrical network of each individual apartment, and not the entrance.
Design features of the bag
The bag design 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 of electrically insulating material.
The device is equipped with fixed contacts, the terminals of which leave the housing and resemble knives in their form. Contacts are connected and disconnected by means of a spring. It is controlled by means of a knife switch.
Turning the handle starts the spring of the switching mechanism. It turns the figure washer and moving contacts a quarter turn. The stroke of the washer is limited to the stop located in the cover.
Movable contacts are attached to plates made of fiber. When heated, the material releases gas, which under pressure moves through the openings of the bag. Instead of gas, unionized air enters the hull and extinguishes the arc.
Due to the simplicity of design and ease of use, bags are widely used in such areas:
- as input switches;
- to switch control circuits;
- as electric current distributors;
- for motor control.
There are many different types of models designed for use in different conditions: in dry and wet rooms, for installation in shields and technological niches.
5 indisputable advantages of devices
The popularity of packet switches for many decades is due to the undeniable advantages of these devices:
- Compactness. Due to the small size of the device is easy to install and easy to use.
- High electric arc extinction rate. Packet switches are rationally designed, so both the electric arc extinction and the device shutdown occur almost instantly.
- Ease of maintenance. Packet owners do not need any special care or maintenance.The main thing is to inspect them in time and replace them if necessary.
- Damage resistance. Devices are hard to break. They do well with mechanical loads, do not suffer from vibration.
- A wide range of applications. Packet 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 lifetime of the bag directly depends on the state of the protrusions of the locking washer. If the main workpiece wears out, the device fails. Because of this feature, there are claims to devices for a relatively short lifetime.
Packet switches cannot be repaired. If they break, they have to be replaced. But during the whole period of operation the devices do not need to be serviced. It is enough to clean them from dirt every six months and check functionality.
The main types and types of bags
Bagners are classified according to various criteria:
- at the point of connection of external electrical cables to the panel (front, rear connection);
- according to the degree of protection of internal structural elements from negative environmental factors (there are open, protected, sealed devices);
- according to the design features of the switches (bag-cam, drum).
Despite the large variety of packet switches and switches, they have common technical and operational characteristics and similar disadvantages.
Thus, the resource spring mechanism is designed for approximately 103 power outages. There are durable models that perform 203-1000 trips. The main condition: the frequency of operation of the mechanism should not exceed 50 for 1 hour.
Product labeling may include such letter and numeric conventions:
- "B" - the switch;
- "P" - switch;
- "P" - batch;
- "G" - sealed;
- numbers 1-4 - the number of poles;
- “H” - direction (2, 3, 4, and also “P” - reverse).
The marking of devices indicate the degree of protection, type of placement, installation features, rated current. Sometimes you can find mark-reduction "forces." And "pl." They are used to denote the material of the body (silumin, plastic). For example, the marking of the device GPPM-2-60 / H2 is decoded as a 2-pole 60-ampere sealed packet switch for 2 directions.
More modern counterparts
Old packet switches were replaced almost everywhere with automatic machines. This is logical, because the requirements for energy consumption and durability of devices have changed. Now widely used RCD (residual current devices), automatic and differential automatic machines, contactors.
Option # 1: residual current device
The device is designed to prevent current leaks. It reacts to a differential current, which contributes to the overheating of electrical cables, which can lead to a short circuit, ignition of the wiring. Also, leaks can cause electric shock.
The RCD must be installed to avoid the risk of electric leakage if it begins to pass by consumer devices. The device acts as a leak indicator that simply cuts off electricity in the event of a problem.
By itself, the device does not protect against overloads or short circuits. This is only possible if connected in combination with a circuit breaker.
Option # 2: Circuit Breaker
These devices have replaced the packet switch. They perform the same functions, however, they 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.
Circuit breakers are classified and labeled in accordance with GOST 9098–78 and 14255.These documents set requirements for device specifications.
Option # 3: differential automaton
This is a combined circuit breaker that simultaneously performs the functions of two devices - a RCD and a circuit breaker. It perfectly replaces a bag pack, is suitable for household power supply networks and is successfully applied at the enterprises.
Differential automatic device prevents leakage, short circuits, minimizes the risks of electric shock. The design of the device includes thermal and electromagnetic releasers. The first prevents overload 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. Devices do not work during a short circuit and are designed only for rated currents.This is their main difference from automatic switches.
In modern residential buildings, out-of-date packet switches are rarely installed. More popular options are difavtomat or RCD in combination with a circuit breaker. But there are cases when the good old packet bag may be indispensable, for example, if you need to turn off the power supply during electrical work.
Packet Connection Diagram
Due to the compactness of the packet switch can be installed in the shield. To do this, use a din-rail. If an old model is chosen, it is necessary to take into account that there will hardly be a latch on it, and self-tapping screws will be required for installation. There are no problems when installing modern packers.
The two input terminals of the bagger are connected to the phase and zero wires that go from the electric meter. And the output terminals are connected to the machines in the panel.
On domestic circuits, the zero and phase wires are marked with blue and red, respectively.
If the product is imported, the colors of the cables may be different, so be sure to read the technical documentation and manufacturer's recommendations. You should not experiment "blindly."
Conclusions and useful video on the topic
We offer a thematic video collection, which will help to understand the design, purpose, principle of operation of various types of packet switches.
Design features of the Soviet packet switch:
Modern models of the CA25 series:
How does the PVM 2 10 bag work:
Video instruction on connecting the RCD and circuit breaker:
Although the popularity of packet switches is decreasing every year, manufacturers continue to produce them. New models are much more convenient and have fewer flaws than the outdated ones. When choosing a suitable bag, you should pay attention to several brands: Legrand (France), Iek (Russia), ABB (Sweden, Switzerland). These are reliable trademarks, and their products are of high quality.