Understanding Keys and Their Types More

In this article, we aim to explain keys and their types to you. Please join us to achieve comprehensive and good results in this writing.

First, we will address the definition of keys.

About Keys

Since the invention of the first light key by John Henry Holmes in 1884, key technology has progressed significantly. With advancements in science and technology and the discovery of various electrical appliances, especially keys and sockets, we are now witnessing the production of various types of keys and sockets with diverse models and applications.

A key is a mechanical device capable of connecting, disconnecting, and passing currents in normal circuit conditions. This mechanism can also support specified additional loads and may pass current under abnormal circuit conditions, such as short circuits.

A key may be able to connect short circuit currents but may not be able to disconnect them.

The operation of an electrical key has two states, fully on (by closing its contacts) or fully off (by opening its contacts).

When the contacts of a key are closed, it creates a closed path switch for current flow, thus supplying energy from the source to the load and consuming the load. In general, a key is a device that, by changing its state, is capable of disconnecting or connecting and changing the status of an electrical circuit.

Due to the highly significant importance of lighting systems in all public and private spaces, it is essential to adhere to necessary standards and specific principles in the production and design of all these elements. Lighting fixtures and equipment must be produced with unique features and full compliance with safety considerations.

Considering the direct connection of switches and sockets to electrical energy, their design and manufacture must necessarily take into account all relevant safety considerations. There are various types of electrical switches; some are designed for use in open and humid environments to be waterproof, and in public places, crystal sockets with chic and luxurious decorations are used, also chosen according to individuals’ tastes and needs.

Electrical switches are used in various applications including domestic, industrial, military, etc. In some cases, multi-way switching (such as building wiring) is used, where two or more switches are connected to control the load from more than one point.

Rotary Switch Models

Rotary switches are offered with accessories and unique features for various applications and have applications in different sections of the industry. These switches supply power to various industrial devices and also perform other functions such as preventing unintended interruptions.

Today, rotary switches are available in various types, including:

– One-way rotary switch

– Two-way rotary switch

– Single-phase rotary switch

– Three-phase rotary switch

– Star rotary switch

– Dallander rotary switch

– Voltmeter rotary switch

– Ammeter rotary switch

These switches are used based on the positions and specific features designed for them. Industrial electricians use these switches to regulate the electrical current required for various devices and machinery. Generally, these switches increase the safety of the production process and prevent various damages caused by electrical currents.

Switch Functions

Generally, switches are divided into two categories in terms of function:

1. Non-disconnectable switches under load or sequencer (C)

2. Disconnectable switches under load or disconnector (D)

These switches are available in the market in two types: mechanical and electronic. Mechanical switches are activated by displacement, pressure, release, or connection of contacts. However, electronic switches do not require physical contact to control the circuit and are activated by semiconductor operation.

Types of Industrial Switches

One of the simplest ways to control electrical appliances is to use various types of industrial switches. Depending on the location and the need for power, these switches are manufactured in different forms.

The mechanism of these switches varies from one another and is produced in various categories. The change in the state of industrial switches is caused by mechanical force, and based on whether this mechanical force is applied directly to the switch or by another form of energy such as electricity, they can be divided into three categories: simple or manual switches, compound switches, and protective switches.

Simple Switches

This type of switches includes lever switches, roller switches, paddle switches, selector switches, and rotary switches. These switches require mechanical energy to change their state, which is directly applied to the switch itself. They are constructed as single-pole, double-pole, triple-pole, etc., and are also divided into several categories in terms of their construction and voltage connection. Additionally, compound switches include contactors, motor protective switches, automatic switches, miniature switches, fuse switches, and three-phase switches.

Types of Mechanical Electrical Switches

According to various factors such as actuation method (manual, limit, and process switches), number of contacts (single-contact and multi-contact switches), number of poles and throws, type of operation and structure (push-button, lever, rotary, joystick, etc.), status (momentary and latched switches), and so on, mechanical switches can be divided into different categories.

Based on the number of poles and throws, switches are divided into the following types:

1. Single-pole, single-throw (SPST) switch

This switch has a single-pole, on-off base consisting of an input contact and an output contact. This switch can turn a single circuit on and off. The contacts of an SPST switch can be either normally open (NO) or normally closed (NC).

2. Single-pole, double-throw (SPDT) Switch

This switch has three terminals, one input contact, and two output contacts. This means that the switch consists of two ON states and one OFF state. In most circuits, these types of electrical switches are used to change the direction of connection between two output options.

3. Double-pole, single-throw (DPST) Switch

This switch is one of the types of electrical switches consisting of four terminals, including two input contacts and two output contacts. The double-pole, single-throw switch operates separately, performing the cut-off or connection simultaneously. This switch has only one ON state, but it can activate two contacts simultaneously, so that each input contact is connected to its corresponding output contact.

4. Double-pole, double-throw (DPDT) Switch

This switch is a dual (on-off) switch consisting of two ON states. The double-pole, double-throw switch has six terminals, including two input contacts and four output contacts, and operates separately, working simultaneously. The two input contacts connect to one set of output contacts in one state and to another set of output contacts in the other state.

Automatic Switches

To better maintain lighting installations, industrial electricity, wires and cables, and machinery against overload and short-circuit currents, fuses, fuse switches, and automatic switches are used.

However, the issue is that firstly, fuses cannot always provide local and selective protection in various types of networks completely and without errors, and secondly, due to the fact that in three-phase networks, often simultaneous disconnection of three phases is necessary and essential, therefore it is not always possible to use a fuse and a fuse switch at the same time.

Additionally, in some cases, it is necessary to automatically cut off the circuit and activate the necessary alarms as soon as the current (voltage) returns or exceeds the allowable voltage drop in distribution networks.

Rotary Switch Features

As mentioned above, mechanical switches are divided into structures such as push-button, lever, joystick, and rotary switches in terms of their operation and structure. Rotary switches are used to connect one line to one of several other lines.

A rotary switch is a type of industrial electrical switch for cutting off and connecting the current. This switch is a switch that controls circuit operation by its rotation. It is made up of an axis and contact arms, and by rotating the switch axis clockwise or counterclockwise, the contacts change their state.

These switches are among the most commonly used switches in electrical panels and are used solely for cutting off and connecting power circuits, typically made in rotary form.

When needed, rotary switches can cut off or connect the electrical current with the help of manual force and have very high resistance to current changes. This product is usually used for low voltage. Rotary switches are made of wear-resistant conductive materials. By turning the shaft, the contacts are opened or closed by cams.

Understanding Keys and Their Types More

Rotary switches can be used to create interruptions in switching, current drifts, and control motors. The application field of various types of rotary switches is in the production lines of various industrial parts and devices.

Rotary switches are designed along with accessories and special features for various applications in different industries. Each of these switches has its utility in a specific sector of the industry. These switches are used to supply and power various industrial devices to prevent unintended interruptions and similar occurrences.

Examples of these switches include board selectors in electrical measurement equipment, channel selectors in communication devices, and band selectors in multi-band radios. Rotary switches consist of one or more movable contacts (handle) and more than one fixed contact.

Application of Rotary Switches

Rotary switches are used to power devices and production lines in factories and industrial centers. For different electrical positions and pressures, rotary switches are designed and produced differently. These switches are offered with various contact arrangements, such as single-pole 12-way, triple-pole 4-way, double-pole 6-way, and quadruple-pole 3-way.

Rotary switches are used for circuit switching and power sources, double-pole switches (city power and generator), multi-stage switches (selector switches), ammeter switches, voltmeter switches, and motor phase displacement switches such as star-triangle, etc.

Rotary switches are made of wear-resistant conducting materials. By rotating the shaft, the contacts are opened or closed by the cams. Often, several cams are mounted on a shaft, simultaneously changing or replacing several pairs of contacts.

One important point to note about these switches is that they are solely responsible for switching on and off. They are used for tasks such as switching, distribution, and changeover systems in designed panels.

Due to their ease of use and affordability, rotary switches have garnered many enthusiasts. Rotary switches can be used to interrupt switching, electric current shifting, and controlling motors. The application field of various rotary switches is in the production lines of various industrial components and devices.

Interlock Operation in Rotary Switches

Some rotary switches, labeled as safety switches with yellow and red handles, may include an interlock mode. Typically, interlock is designed so that when the switch is in the off position, the panel door is opened. Additionally, these switches have locking and marking features in the off position. Therefore, they can only be operated on internal equipment panels when the switch is in the off position. Safety switches are of the load-break type and must be able to disconnect the current of the largest motor in the network when locked in the off position.

Types of Rotary Switches

Rotary switches are divided into the following categories based on their functionality: one-way rotary switch, two-way rotary switch, single-phase left-turn-right-turn rotary switch, three-phase left-turn-right-turn rotary switch, star-delta rotary switch, delta-star rotary switch (for delta-star motors), voltmeter rotary switch, and ammeter rotary switch. Rotary switches provide rotary movement to create or interrupt operations at different positions.

These products can simultaneously control three-phase circuits with voltages of 400 and 800 volts and electrical circuits with a voltage of 120 volts. Each type of rotary switch is designed for specific conditions and situations. Industrial electricians use these switches to regulate and establish the required electrical currents for various devices and machinery. These switches increase the safety of the production process and prevent various damages caused by electrical currents.

Various accessories are available for rotary switches. For example, installed handles with screws or by hand, with or without front plates, separate front plates with or without engravings, additional switches, covers, and installation kits.

Buying a Rotary Switch

In the initial stage of purchasing a rotary switch, the appropriate series of rotary switch should be selected based on the approximate amperage rating of the switch, the variety of demanded switches, economic considerations, and the location of use.

The T series of rotary switches are available in the amperage range of 12 to 40 amps. This series, besides its attractive appearance, has a high level of protection. The switching part of the switch has an IP65 protection rating (complete protection against dust and water jets from all directions), while the switch body and terminals have an IP20 protection rating (terminals protected by a cover).

In the next stage, considering the type of electrical load that needs to be switched, controlled, or regulated by the rotary switch, and the definitions related to the application classes, the amperage rating and code of the switch are selected. The amperage code of the rotary switch is a three-digit numerical code. Then, based on the required functionality of the rotary switch in terms of the number of switching contacts, the number of rotational positions, rotation angles, terminal connection sequences, and terminal marking methods, the functional code of the rotary switch is chosen.

The functional code of the rotary switch is the same for each series of switches. In the final stage, considering the desired installation method (on the panel, panel floor, interlocking with panel doors, or installation inside a surface-mounted wall box), as well as the type and shape of the switching mechanism, the color of the panel and handle, and the protection rating, the model code of the switch is determined.

How to Buy a Quality Rotary Switch?

A rotary switch, as one of the essential equipment for supplying power to industrial machinery and equipment, holds great importance. This switch plays a crucial role in the safety and energy supply of industrial machinery. Due to its simplicity and reasonable price, the rotary switch is commonly used as equipment in industrial electrical panels and control panels. Reputable types of rotary switches with reasonable prices are available in the market.

To purchase this product and inquire about its price, you can contact experienced professionals in the field of electrical engineering. They can help you select and purchase the rotary switch that meets your requirements.

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