Voltage control relay: principle of operation, circuit, connection nuances

Voltage relay RN 113, connection methods and 4 modes of its operation

RN-113 is designed to disconnect consumers in case of unacceptable voltage fluctuations in the 220V supply network. After restoring the parameters of the supply network, the relay independently restores power to electrical appliances.

On the front panel there is a seven-segment LCD display showing:

• network voltage;
• the value of the parameter to be set;
• network parameters when disconnected (indicator blinking);
• time before switching on.

The parameters are set using the knobs on the front panel.

The rated current of the device is 32A. If it is necessary to connect a load of greater power, it is connected through a starter.

Operating modes

The device operates in four modes:

1. Standard voltage relay. At the same time, full protection of consumers is provided.
2. Maximum protection. Shutdown is performed only when the overvoltage of the supply network is above the specified limits.
3. Minimum protection. Triggered when the potential drops below the allowed value.
4. Time relay with turn-on delay.

Before connecting the RN 113, you can watch a video on this topic on the Internet.

The picture shows the connection diagram of the voltage relay RN 113 for the house cx to the 220V network.

Connection RN-113

We understand the voltage relay at 40 A

The volt controller, according to relay experts, is used to protect large houses as well as industrial complexes. It is necessary to study the principles of operation using an example, we chose a 40 A device as such.

This device, designed to protect the electrical network, is also necessary like an automatic machine, but has a slightly different purpose, namely, monitoring the current voltage. Random surges are considered to be the main reason for the failure of expensive equipment that is sensitive to network noise. Repair of damaged equipment is expensive for the owner, because breakdowns due to voltage are not included in the list of warranty cases.

Such jumps are extremely short, only a fraction of a second (a few seconds at most) before the substation's protective mechanism is triggered.This short time period is enough to shoot out all the equipment. To represent the problem globally, take a look at your outlets, how many appliances are on at the moment? Most of them will “burn out” in case of a voltage drop without a voltage relay.

Design features of the relay

outdoor structure

It is better to consider the design on a live working example. We chose the 40 A relay RN-104 manufactured by Novatek Electro. The case, like most other devices, is designed for mounting on a DIN rail. The front panel has an indicator of three segments, by which you can determine what is currently happening with the power grid. The device has three regulators and the same number of terminals, while being one of the simplest representatives of its class of electrical devices.

The device connection algorithm looks like this:

1. The phase is connected from the machine.
2. A zero or second machine is connected.
3. Consumption or machines are connected.

The choice in the second and third paragraphs depends on the characteristics of the target electrical network and whether you are building a network from scratch or improving a finished one. The connection is made according to the brief scheme displayed on the side of the device.

Internal construction

If the device is disassembled, you will see that the design is not so intricate. On the device without a cover, you can understand something about its assembly. So, thin, neat soldering will tell us that the process did without human participation. We recommend choosing devices manufactured at enterprises where a person participates only in the test stage, and the rest is done by the production line. Then the percentage of potential marriage is noticeably minimized.

In fact, this relay is two boards: power and control.The first is a large 40 A relay, which allows the device to operate with loads up to 9 kW. Its conclusions are soldered to copper leashes, leading the connection to screw terminals.

Relay setting

The manufacturer went to meet the client and programmed the main functions in the form of a variable menu:

• reactivation time;
• lower threshold;
• upper threshold.

In this case, all parameters are set with a potentiometer, which you just need to turn and set the number on the indicator. Full-fledged display indicators are found only on expensive models, and small digital ones are installed on almost everything. The most ideal setting is the following:

• AR - 180 sec;
• lower threshold - 190;
• the upper threshold is 245.

This device has a useful hysteresis function of 5 volts: at close to threshold values, the device does not turn on. This helps to get rid of continuous disconnections / inclusions when the voltage in the network fluctuates on the verge of permissible. In this case, the device introduces an additional "intelligent" threshold and is not connected until the situation is normalized. The availability of this functionality should be specified for each model separately. We believe that it is very useful, so it is worth taking care of it.

Also in a high-quality relay there is a mechanism for controlling a smooth drawdown of the network. This happens when large consumers are turned on, such as an iron, microwave, air conditioner. The electrical network of the apartment at this moment sinks by 50 - 60 percent, after which it is also smoothly restored, the procedure takes from 8 to 12 seconds. A smart device can recognize such moments and not turn off the network after turning on the kettle.

Connecting a three-phase pH - 4 schemes

The three-phase relay is intended primarily for the protection of AC motors connected to a three-phase 380V network. With absence three-phase loads, three single-phase loads are installed devices.

There are four main connection schemes for this device:

• All equipment is connected directly from the device, without a contactor. This option is used for loads up to 7 kW.
• Part of the equipment with lighting lamps is connected through the device, and part through an additional starter. Such a scheme, after the appearance of power, turns on the lighting, and the electric motors must be started manually. This is necessary to check the condition of the equipment after an emergency stop.
• Before the starter (after the introductory machine). This scheme protects all installed equipment from problems on a suitable network. It has a drawback - if the contactor fails (one of the contacts burns out), the electric motor remains energized, works “in two phases” and fails in a few minutes, and sometimes seconds.
• after the starter. This circuit protects the motor from proper voltage problems and starter failures, but leaves the rest of the equipment unprotected.

Scheme of connecting a three-phase starter to the LV

Classification and types

Voltage relays are classified according to:

• location and installation;
• the number of phases of the electrical network.

By connection type

There are three ways to place and install such devices, which determine the type of their inclusion in the electrical network:

Voltage relay plug-socket.

Model "RN-116" type plug-socket

This type of placement allows you to control the voltage supplied to only one consumer connected to the plug-socket unit. In this case, the voltage applied to other load elements is not monitored or controlled.

Voltage relay-extension.

This type of electrical equipment is an extension cord equipped with a built-in control relay. When using it, you can power a group of household appliances and devices, thereby protecting them from power surges.

In this case, the main limitation of use will be the maximum allowable power of the connected devices, determined by the magnitude of the load current.

Model "Zubr R616Y"

Voltage relay for DIN rail mounting.

This is the most functional option for placing such protection elements and is due to the fact that a relay of this design is installed in the main switchboard (MSB), input distribution device (ASU) or lighting panel, thereby making it possible to protect the entire electrical network of an apartment or a country house. The main condition for choosing when installing in this way will be the correspondence between the power of the device and the total power of the connected load.

By number of phases

Everyone knows that electrical networks are single-phase and three-phase, respectively, and electrical devices are designed for these voltage classes. A single-phase control relay is a device designed to work in electrical networks for various purposes with an operating voltage of 220 volts. The design and methods of placement of such protective equipment are discussed above.

Model "RNPP-301", mounted on a DIN rail

Three-phase models are installed in the ASP or main switchboard of a country house (cottage), if their power supply scheme provides for connection through a three-phase circuit with a voltage of 380 volts.

In this case, it is possible to protect the entire internal power supply network, as in the case of using a voltage relay installed in the lighting (apartment) panel.

This is interesting: Wiring diagram for a 380-volt outlet - we disassemble thoroughly

Description of popular models

Connection diagrams and settings for most models offered by domestic manufacturers have much in common, they can differ only in details.

Devices under the Zubr brand

The protective devices of this series are connected to the power supply circuit in two ways:

• simplified internal connection;
• together with RCD and circuit breaker.

In the first case, the load is connected directly to the output of the device, and in the second, the control circuit is closed through the RCD and AB. This inclusion of the Zubr allows you to protect the line not only from voltage drops, but also from current leaks.

The devices have different versions, differing in rated currents (25-63 Amperes). The upper threshold is from 220 to 280 in steps of 1 Volt, and its lower value is from 120 to 210 Volts. The reconnection time to the line varies from 3 to 600 seconds. The adjustment step is 3 seconds.

RN series

RN-111

The RN-113 model is switched on after the electric meter and allows manual setting lower and upper threshold values tripping, indicated on the display built into the front panel. The device is able to automatically connect the power supply when its parameters are restored after strong power surges.

For normal operation of devices of this series, a power margin of at least 20% is required.

In addition to the limit values, the indicator displays the network parameters when the consumer is turned off, as well as the time remaining before turning on. Rated current is 32 Amps; if desired, it can be increased by installing a magnetic starter.

UZM series

Voltage relay UZM-51M

The UZM-51M device, installed immediately after the electric meter, is designed for a rated current of up to 63 Amperes and occupies 2 modules on a DIN rail at once. Its standard width is 35 mm. The maximum setting for the upper voltage limit is 290 Volts. The lower threshold for overvoltage operation is 100 Volts.

The reclosing time, manually set by the user, can take two fixed values ​​- 10 seconds and 6 minutes. UZM series devices can be installed in networks with any grounding system: TN-C, TN-S or TN-C-S.

Devices from the company "DigiTOP"

ILVs of the V-protektor series are used only for protection against voltage surges. They are rated for rated currents from 16 to 63 Amps. The upper threshold is set in the range from 210 to 270, and the lower - from 120 to 200 Volts. Time of automatic recovery of the included state – from 5 to 600 sec. The three-phase device V-protektor 38 is designed for a maximum current of not more than 10 Amperes.

ABB devices

Voltage relay ABB

Popular on the market, ABB CM series relays allow you to adjust the response threshold in a wide range of values ​​(from 24 to 240 Volts in single-phase circuits and from 320 to 430 Volts in three-phase circuits). The recovery time for most models is from 1 to 30 seconds.

Which type is preferred

Single-phase voltage relay RN-111M 1F NOVATEK

If the user is concerned about the safety of an expensive model of a refrigerator, for example, and all other appliances are already protected by a stabilizer, it is more convenient to purchase a sample of the “socket-plug” type.

In this case, the installation of a common automatic device will be redundant, as it will lead to unjustified costs. This option is more suitable for residents of city apartments who do not want to spend money on installing an ILV in a switchboard (you will have to invite an electrician for this).

Regardless of the operating conditions of the control relay, it should be understood that installing several devices in a socket will cost more than one in a shield.

When there is no stabilizer in the house, and its owner wants to reliably protect kitchen and room equipment, it is wiser to choose a device mounted on a DIN rail. When installing several relays - one for each protected line - the possibility of damage to expensive equipment is completely eliminated. They are optimally suited for a private house, where they can also control a three-phase network.

Features of common types of voltage relays

Types of voltage relay

Thanks to the voltage relay during power surges, the device will not burn out, the board will not melt, and the electric motor will not fail. The cost of devices is considerable, but they pay off. It is better to prevent accidents than to buy new equipment.

There are several types of control relays from different manufacturers on the market. They have the same principle of operation, although the design and set of additional functions may differ.

Modern devices have a digital display. It allows you to monitor the voltage level in three phases. There are also additional settings.With their help, they regulate the operation of the device and provide simplicity and ease of use.

RCD connection diagram

In apartments, connecting a three-phase network is rare. This option is popular for private houses. The protection device in them is connected in several ways:

The voltage relay 380 V 2-pole is not suitable for the home. Use 4-pole analogues. They connect 1 zero core and 3 phase. The scheme is complicated by the fact that each line is equipped with its own RCD.

It is important to choose the right wires. For a single-phase network, the standard version of VVG is suitable, but for a 3-phase network, a fire-resistant VVGng is needed.
General RCD for 3-phase network + meter

The circuit contains an electricity meter. Group RCDs are located in the service system of individual lines. This scheme requires the installation of a large electrical panel with many wires and electrical appliances.

If there is not enough power

There are often situations when it is necessary to install protective relays on powerful equipment, but at the same time the protective unit itself is not suitable according to the technical data. There is a way to increase the value of the rated current by installing an intermediate relay. The idea is very simple: the load is connected to the network through a powerful contactor, the coils of which, in turn, are connected through a protective block. As a result, the main load does not go through a relay that is not overloaded.

Connection is carried out in the following sequence:

• We mount the protection relay and the starter on the DIN rail next to each other.
• When the power is off, we connect the “phase” and “zero” relays to the power input.
• With a wire of the desired cross section, we connect the "phase" to the input of the break contact of the starter.
• The output of this contact is to the load. "Zero" is taken directly from the line.
• We connect two wires to the starter coil. We bring one to the zero bus, the other to the output of the breaking contacts of the protection relay (at the bottom of the device case).
• The input of the breaking contacts of the relay is connected to the phase wire of the network.

It is now possible to control a load significantly higher than the rating of the protective relay.

This is interesting: Product design: The electrician himself

The principle of operation of the relay

The whole point of the design is to control the supply of current. Overvoltage or insufficient supply can damage the equipment.

Relay installation is essential when:

• line breaks;
• bad weather conditions;
• a drop in electricity;
• phase overload.

The device incorporates a microcircuit that controls the operation of the device as a whole. It can reduce and increase the voltage, signal, turn the device on or off. RKN is able to equalize the operation of the network.

The voltage varies in the range of 100-400 watts. Weather conditions or a thunderstorm significantly increase the performance, which leads to overvoltage. The device may burn out from sudden power surges. For this, special voltage limiters are used.

The device always works instantly. Its difference from the stabilizer is that the relay turns off areas with strong surges, and the stabilizer distributes and adjusts the feed. When emergencies occur, the presence of a relay is considered the most effective.

What voltage relay to buy for your home?

If you need to protect equipment in the house or apartment where you live permanently, then it is better to take a relay for a DIN rail.In order to select a suitable ILV, it is necessary to calculate with which switched current it will have to work. To do this, use the following formula:

Pr = P*K, where Pr is the power for which the ILV is designed; P is the total power of all electrical appliances in the house; K is the correction factor for the operation of electrical appliances. Since it practically does not happen that all devices work simultaneously, the correction factor is taken to be 0.8. However, if all your devices will work simultaneously, then take a factor of 1.

Suppose we need to protect a 2 kW boiler, a 2.4 kW washing machine, a 1 kW microwave and a 7 kW boiler. Then Pr = (2+2.4+1+7)*0.8 = 11 kW. Since the switched current is indicated in the characteristics of the device, we translate 11 kW into amperes. 11000/220 = 50 A. Choose the closest suitable one, for example, RBUZ D-50t at 50 A.

It is also worth paying attention to the number of phases with which the device can work. Socket devices are designed for single-phase networks

For a three-phase network, an appropriate ILV will be required. Moreover, the device will show the operating voltage for each phase separately. Three-phase relays are recommended to be installed to protect machines powered by a three-phase motor.

Types and designs of launch vehicles

All maximum voltage relays are divided into types:

• single-phase;
• three-phase.

RN plug-socket (V-protector 16AN, RN-101M)

Additionally, mechanisms are classified according to the installation method. The buyer is offered the following device options:

• Plug-socket. The device has on one side the appearance of a plug, which is inserted into the socket. On the other hand, there are sockets for connecting household appliances. The equipment is powered as if through an adapter.This type of device is designed to serve one piece of equipment or a small group. All voltage parameters are displayed on the board. The wizard can independently set their upper and lower values ​​using the buttons.
• Extension. This is a block with 3-6 outlets familiar to most users. All household appliances connected to the extension cord are controlled by relays and are protected from power surges.
• Digital mechanism for DIN rail device. These are more powerful devices that are placed on the switchboard. Thus, the electrical contactor protects all appliances around the house. The main feature of such a relay is a very wide range of settings and a large number of independent modes. For example, switching on time and delay, relays for minimum and maximum voltages.

Relay connection procedure

It is very important that the control device is included in the circuit of any mobile unit, which includes a three-phase electric motor. If there is no such relay in the equipment, incorrect phase sequence can lead to serious consequences - from malfunctioning of the device to its failure

Clearly about the connection on the video:

If at least one phase cable breaks, the power unit will quickly overheat, and the device will become unusable in a matter of seconds. To prevent this, a thermal relay is often installed on the contactor instead of the control relay. But the problem is to choose it correctly and adjust it according to the rated current. This requires a special stand, which not everyone has. Therefore, installing a phase control device is an easier way to solve the problem.

The principle of operation of the RK is based on the fact that the device captures negative sequence harmonics that occur in the event of a phase imbalance or a break in the current-carrying wires. The analog filters of the control device separate them and send a signal to the control board, which turns on the relay contacts after receiving it.

Wiring diagram phase control relay does not vary in complexity. All three phase conductors and the neutral cable must be connected to the corresponding terminals of the device, and its contacts should be put into the break of the solenoid of the magnetic starter. If the device is in normal operation, the contactor is on, the relay contacts are closed, and the equipment is energized.

In the event of a malfunction, the contacts of the control device are opened, and the power supply is turned off until the network parameters are restored.

Most often, factory-made relays that are commercially available are used to protect household appliances. But sometimes they are made by hand. Here is a diagram of a simple home-made device, on which there are graphic symbols of the elements included in the circuit.

Characteristics

The main function of the control relay is to constantly measure the effective voltage value. In case of exceeding the nominal value or, conversely, decreasing below the established norm, the power contact of the device opens and the phase is disconnected. Thus, the external supply network is open to internal wiring.

All devices of this type are divided into single- and three-phase.In the first case, only one phase is switched off, and in the second case, all three phases are switched off simultaneously. If a three-phase connection is used in domestic conditions, it is recommended to install single-phase control relays for protection, individually for each phase. In this case, voltage surges that occur in any one phase will not cause other phases to turn off. Three-phase protective devices themselves usually monitor the voltage on electric motors and other similar consumers.

One of the most important characteristics of single-phase devices is the magnitude of the current load. It is this parameter that makes it clear what electrical power is allowed to pass through a particular device. The current load is primarily taken into account when choosing a particular device.

However, when choosing the right voltage relay, you should pay attention to the manufacturer's markings. It indicates the operating value of the current or the level of load transmission, which is lower than the operating current at which the power contacts are disconnected.

In this regard, experts recommend taking this factor into account and choosing a device with a power that is 20-30% higher than the total transmitted power. That is, when a 16 ampere circuit breaker is installed at the input, the voltage relay must be designed for a higher current of 20-25 A, one step higher than the standard range.

Classification and types

Extension cord with voltage relay

Known types of ILVs differ in the type of power used in the dwelling, according to which they are single-phase or three-phase. 220V supply voltage relays are installed in urban housing, and their three-phase counterparts are used in offices or enterprises.Often they are found in private houses, to which a branch from the 380 Volt line (three-phase power) is connected.

According to the method of connection to the serviced line, the known models of the 220V mains voltage control relay for the home are divided into the following types:

• adapters plugged into a regular outlet;
• extension cords with several sockets (from 1 to 6);
• devices mounted in a panel on a DIN rail.

The first two positions are transitional devices that provide protection for individual household consumers. In this they fundamentally differ from the ILVs installed in the distribution cabinet. Entire groups of electrical appliances can be connected to them.

How to avoid 3 mistakes when installing a pH

Inexperienced electricians sometimes make the following mistakes:

• Wrong connection of wires to the relay terminals. It will not turn on at all or a short circuit will occur when turned on.
• Only suitable wires are connected. The relay will operate, but the equipment will remain unprotected.
• Different single-core wires of different cross-sections, single-core and multi-core or copper together with aluminum are connected to one terminal. This will lead to poor contact, heating of the terminal with burnout of the device.

Studying the instructions for the device and the PUE (Electrical Installation Rules) will help to avoid them.

TOP-5 manufacturers of voltage relays

The following companies are the most popular in the market of protective devices:

• Novatek-Electro, Ukraine. This company produces devices RN 113 and RN 111, as well as those manufactured under the brand name Volt control
• DS Electronics LLC, Ukraine. This company manufactures the Zubr ILV.
• Energohit LLC, Ukraine. This organization manufactures products under the brand name DigiTop.
• Electrotechnical company MEANDR, Russia.It produces protection devices against high-voltage impulses and overvoltage UZM-50MD, UZM-51MD.
• "Evroavtomatika F&F", Belarus. The only company that produces RKN for installation in a junction box instead of a conventional outlet.

Voltage measurement before choosing

In general, voltage relays are a budget option, and today they should be in every apartment in a good way. It's just that the upper and lower thresholds for infrequent operations must be set correctly. And for this, you must at least have a multimeter and empirically measure the input voltage during peak load hours.

It is advisable to take three measurements - in the morning, in the evening and at night. And after that, based on the results, set the relay thresholds.

Any normal person will be afraid to set such thresholds on the relay without any other protection, and continue to use electricity with such unsatisfactory performance.

How to choose a voltage monitoring relay

Extension relay

To make the right choice when buying a machine, you need to be guided by the following criteria:

Type and type of device. The most expensive, but powerful - rack and pinion. The simplest and most affordable is a fork.
The presence of auxiliary options, manual settings, auto-adjustments. It is desirable that the device has a display.
Overheating protection function

This parameter makes the operation of the relay more reliable.
It is important that the PH be made of polycarbonate. This material ensures the incombustibility of the device in case of emergencies.
When buying a single-phase mechanism, you need to determine the power of the relay

Household equipped with 100 A power contacts
Here it is desirable to increase the power indicator by 25% and, taking this into account, purchase an automatic machine.
All three-phase RH are designed for a current of 16 A.
It is worth paying attention to the manufacturer of the device, the appearance of the device.

Before connecting the RH, it is necessary to install a circuit breaker for emergency power failure.

ILV connection diagrams

In the shield, the voltage relay is always installed after the meter in the break of the phase wire. He must control and, if necessary, cut off precisely the “phase”. There is no other way to connect it.

Most often, for single-phase consumers, a standard circuit with a direct load through a relay (+) is used.

There are two main schemes for connecting single-phase relays of the mains voltage regulator:

• with direct load through ILV;
• with connection of loading through the contactor - with connection of the magnetic starter.

When installing an electrical panel in a house, the first option is almost always used. There are plenty of various models of ILV with the necessary power on sale. Plus, if necessary, these relays can be installed in parallel and several by connecting a separate group of electrical appliances to each of them.

With installation, everything is extremely simple. There are three terminals on the body of a standard single-phase relay - “zero” plus phase “input” and “output”. It is only necessary not to confuse the connected wires.