Intermediate relay: how it works, types, marking, adjustment and connection

Most of the electrical circuit is designed and used in low-voltage systems. The main purpose of this kind of circuits - the transformation of incoming signals on the preset algorithm of actions.

For electrical isolation of the low-voltage circuit and a higher nominal voltage employ an intermediate relay. Due to the small size and reliability of these devices are widely distributed in various areas.

Purpose and functions of the device

This type of switch is an auxiliary object Electric circuit. samples versatility allows their use in automated, protective and regulating circuits.

It is used in cases where there is a need in the synchronous closing or opening of several independent electrical circuit, in other words - the reproduction of live channels.

The contactor can be used as a regulator of a power relay, through which circuit switching is performed with a high voltage.

Take, for example, such a situation: there is need to supply current to the coil switch, where the maximum instantaneous value elektroveduschey force when the - 63 A. However, to perform such a task using a single electromagnetic device is not possible.

So initially you need to supply power to the coil core of the separation device that uses its own communication, including contactor with more power, which task switching and greater force will be assigned electricity.

Also, item can be used to create an artificial delay relay action or, as they say, for the formation of the holding time.

The design of the device structure

Electromagnetic devices are connected to a circuit carrying out control or adjustment items, which are connected to the power node for conversion. Running can be influenced by various kinds of factors: the power supply, light energy, hydrostatic or gas pressure.

According to the standards, simple contact device is coordinated by the three main areas: receptive, intermediate and CEO. Each of them is represented by individual mechanisms responsible for certain actions in the switching system.

Primary, so-called sensitive element produces a response to the input parameter and transforms it into a physical quantity required for operation of the contactor.

Such a sensing mechanism embodied in the electromagnetic coil with a core - in the diagram is denoted by reference 4. Depending on the network, to it can be connected or a variable or a constant voltage.

Intermediate starts comparative analysis of the converted values ​​with the sample laid. Once reached a predetermined value, the sensor assembly transmits the signal to the executive mechanism. This region consists of counteracting springs (1), and dampers.

In a production portion by the switching lines (6) located on the housing of the block, is reproduced effect on the subject line and the contacts close.

Operating principle of the contactor

The algorithm of this type of relay incorporated the use of electrodynamic forces generated in a ferromagnetic material during the passage of electricity in a spiral turns of insulated wire coil.

The initial location L-shaped plate (anchor) is fixed by a spring. Feeding current to the magnet, the anchor switch contacts located thereon overcomes the spring force and extends to the magnetization field.

When moving the shank situated on the contact plane, contact touches the lower diagram, moving it downwards. If the coil stops the supply of electricity, the spring pulls back yoke and the device takes its original appearance.

Consider the example of how the type of electromagnetic relays in the car.

If you plug it in the following steps will be reproduced three-phase asynchronous motor:

1. Start - switch signaling.
2. Triggering the starter.
3. The closure of the last couple of contacts as a result - starting the engine mechanism.

In addition, it is responsible for the switch off of the motor at break reversal. This eliminates the problem of a sudden stop of the engine.

It is also important to know that the electromagnetic relay can be fitted with several groups of adjusting contacts. the last number of completely dependent on the purpose of the particular device model.

Species transfer switches

Contactor intermediate type discharge the basic execution units. Otherwise blowout conditions become more stringent, resulting in unprofitable production, for example, of such powerful sources such as thermal power plants.

Used switching methods

Classification electromagnetic switches is performed according to the basic features and characteristics, namely:

• by the method of activation;
• design features - the number and type of winding, as well as the number, the state and the power contact lines;
• the principle of operation;
• of operating time and return to the starting position.

Based on the destination, the contactors are made with coil voltage or current, or two species at the same time. There are two standardized method for their insertion.

The first type of connection - seriesny. The device is serially connected windings in the sections other devices and functions of the current flowing through the circuit of this circuit.

Next - shunt. Included rated operational indicators source voltage.

Features of the device structure

Features of the device assume the samples with one coil voltage or current windings (RP-23, RP-252), two (RP-11) and three infrequently.

DC Relay (RP-23) produced on such nominal voltage values: 12, 24, 48, 110 and 220, AC (RP-24) - 127, 220 and 380 V.

Switches RP-23 and RP-types 24 intended for operation on the galvanic current and have contact lines 5, which can be applied in different combinations. The differences between them in their device.

The second kind of devices equipped with integrated mechanical decoupling pointer. Their power is consumed when the base voltage of 6 watts. Series RP-25 and RP-26, working exclusively on the alternating current and are arranged in a similar manner as the previous devices.

Additional element - in closed loop with the core coil, designed to eliminate vibration of the movable part of the mechanism. Their energy consumption is the same - 10 watts.

Recently ChEAZ ZAO (for the production of electric apparatus factory in Cheboksary) instead of the above modifications to produce a reorientation of the upgraded model. This switches RP16-1 (galvanic current) and RP16-7 (alternating current) equipped with two NC and four normally open contact groups.

Two- and three-winding peripheral devices are generally used in a few cases.

Consider what problems they solve and what type of instrument would require:

1. When the activation mode needs of current and holding the voltage, e.g., a series of RP-232 with a single turn of the working coil.
2. If action is required by the device voltage and abstinence from electricity - RP-233 on the two retaining current turn.

In the same way, instead of the above-described contactors ChEAZ introducing new SH-16-2 samples - RP16-4 and RP17-1 - RP17-5.

The principle of operation switches

Contact devices are used in the telecommunication segment, and automation. Based on the principle of work, they are divided into neutral and polarized (pulse) species.

The main difference between them - in a first displacement of the armature is not subject to the polarity control signal, the second - on the contrary, have a direct dependence on the direction of motion of charged particles in the winding.

Neutral switches are very simple device consisting of two systems: the track and the magnetic type. In the contact group there are two fixed and one movable contact generalized. The magnet assembly composed of armature and yoke of the electromagnet.

Additionally electromagnetic relays divided by the nature of the motion of the armature: corner (float) and retractable. To reduce the magnetic forces of resistance air passage between the movable plate and the core. Last is equipped with a pole piece.

Such relay wiring used in production machines and machine control systems. RES-6 is one of a low-voltage contactors neutral class. The apparatus may take the form of toggle or monostable. Its nominal operating voltage 80-300 V, switching current - 0.1-3 AB.

Pulse category is made up of the same systems. However, the magnetic portion impulse relays It is further equipped with two rods with a winding, and the contact rod and the permanent magnet flux creates polarizing.

Thanks to this type of aspiration supplying the electromagnetic force acting on the anchor is changed based on the direction of power flow in the coil.

Contactor IMSH1-0,3 widespread as a track relay mechanism in protective pulse (RP) schemes galvanic current. IMVSH 110 employ in AC circuits. Technically, it consists of a diode bridge converts AC power to a constant value.

Response time and return

The response time of the intermediate gear (t attraction) - the period from the time of receipt at the drawdown command to start increasing the output parameters. This value is subject to structural features fully relay connection circuit and its input signal.

Trip time (t released) - interval from the signal supply to shut down until the output parameter smallest value.

To consideration the type of relay high demands on speed.

Depending on the time of the interval, are classified as follows: device:

• high-speed - slowing down time and off attraction to 0.03 with (e.g., REP37-13, RP 17-4M);
• normal - with 0.15-0.20 (series RE);
• slow - with 1.0-1.5 (NMM4-250, NMM4-500);
• temporary - 1.5 to (RP18-2, RP18-5).

In the market of such modifications presented by various manufacturers. Therefore, depending on the brand, the relay structure can be slightly different. However, with the markings on the device that can accurately determine the parameters of the product.

What tells the marking?

The marking of contactors specify the full set of data on the purpose and design features, including the climatic design information.

We consider in detail the structure of a symbol for example PE41 (H) (*) (*) (*) (*) (*) / (*) (*) (*) (*) 5:

1. RAP - The relay electromagnetic intermediate.
2. 37 (H) - the development of number.
3. (*) - designation kind of current in the circuit consisting of the winding 1 - dc; 2 - AC.
4. (*) - type of deceleration: 1 - slow at inclusion; 2 - delayed when disconnected.
5. (*) - value based on the number of windings;
6. (*) (*) - the numerical value of make and break contacts;
7. (*) (*) - voltage or power winding current: constant (D) and a variable (A);
8. (*) (*) - a designation Elektrosila holding windings;
9. (*) - type of technology and the rear connecting conductor lines: 1 - with fins soldered; 2 - mounting with screw fixation; 3 - fixing terminals to split block.
10. (*) 5 - climatic design and placement category according to GOST: YX - moderately cold; In - all-climate.

When you select the required model of the switching device are taken into account not only the electrical parameters, but also the environment in which it will work.

Despite the high quality provided by the switch, the main drawback lies in the contacts system. It is expected that the net connected group may be located only in sealed vacuum. If it affects the main negative factor - contact with air - they began to form an oxide film.

Nuances connection and adjustment

After installation of the intermediate gear it must be connected to the wiring. To this end, the coil contacts will be involved, as well as additional connecting elements. Normally, the device has several pairs of contact: NO - normally open and normally-closed (NC).

The first position is supposed to complete deprivation of energizing the coil signal. Since it has no polarity, the internal connection of the contact group may be performed in a chaotic manner.

To connect a review mechanism, consider the schematic instructions. Estimated voltage in the coil may be 12, 24 or 220 W.

Regulation of electronic starter analyze the example of the most common model RP-23.

The process includes the following steps:

1. Checking voltage start and return to supply electroplating current source to the coil, we provide unsharp regulation.
2. At the time of the attraction of the armature at the mobile node of the system has to be a joint course of 0.1-1.5 mm. hem shank method on the L-shaped plate carry out a corrective procedure.
3. Between active and inactive level of the contact gap is set within the range 1.5-2.5 mm. deflection adjustment is made urging gon fixed contacts and the upper stop of the moving system.
4. At the end of the armature arrangement (circuit) failure is inactive contact 0.3-0.4 mm.
5. In the mid-plane of the movable and stationary contacts must be the same. Adjustment is performed by moving the plate and the guide bracket.

The same method is reproduced and setting relay RP-25 parameters but eliminated the gap between the coil core and the armature in the attracted state.

Conclusions and useful videos on the topic

The principle of operation of the electromagnetic relay, where applicable, also the basic indicators of the reliability of the instrument. More details in the video:

Selecting the desired model of the device, go to her and set-up. Basic nuances described in the present plot:

Technological development structures intermediate relays have always been aimed at reducing the weight and dimensions, as well as increasing reliability and ease of installation devices. As a result, small contactors steel placed in a sealed enclosure filled with compressed oxygen or with addition of helium.

Due to this, the internal elements have a greater service life, running smoothly by performing all laid teams.

Tell us about how to choose an intermediate cut-out device for a home electrical outlet. Share your own selection criteria. Please write comments in the block located below, place the photo on the article topic, ask questions.