Does a voltage stabilizer require a grounding

How to choose a voltage regulator

Voltage stabilizer - a device that is indispensable in every household. It is also needed at the manufacturing site, but here we focus on household stabilizers, which are designed to protect household appliances and equipment from voltage spikes and currents. Typically the voltage in the trunk is 220 or 380 V at a frequency of 50 Hz. Due to various factors - connection of consumers with high power, peak loads in the evening or morning hours, accidents on power lines - the current can drop by 25 to 40 in both directions Percent voltage deviate from the set parameters.

Too low and too high a mains voltage is both dangerous and undesirable for household appliances. Sudden jumps are doubly dangerous. Fridges, televisions, household pumps and boilers, computers just can't work anymore. Input circuits, complicated electronics of adjustment blocks can burn out, other damage can occur, which is very expensive to repair.

How the voltage regulator works

To determine which voltage stabilizer is best for the house, you need to know the basic principles of its operation, what stabilizers and what important parameters to use and what to pay attention to.

The stabilizer is essentially an adjustable feedback transformer. Alternating current from the line enters the primary winding and excites approximately the same current in the secondary winding to which the loads are connected. If the number of turns on the primary coil is changed, the current in the secondary coil, in which the number of working turns remains the same, changes accordingly. Built on the change in the transformation ratio of the number of turns and the work of adjustable transformers.

The inductive coupling is very reliable and does not allow any direct contact between the windings - only via a metal core. Such transformers allow you to change the parameters of the output current almost instantly. You just have to configure the control of the pantograph depending on the voltage in the supply network so that it increases when the current in the network of the secondary winding drops and decreases when the voltage is exceeded.

A regulated transformer is the basis of all household stabilizers. Differences only affect control schemes.

Types of voltage stabilizers

The market is dominated by two types of stabilizers - electromechanical and electronic.

Electromechanical voltage stabilizers

In electromechanical stabilizers, the current in the coil is regulated by a contact slide that moves along the surface and changes the number of working turns. Anyone who remembers a school physics course can imagine a rheostat from experiments in the classroom. The electromechanical voltage regulator works in roughly the same way, only the slide is not moved by hand, but by means of an electric motor.

Electromechanical stabilizers are very reliable and allow you to smoothly change the voltage in the secondary coil. However, due to their simplicity, they also have a number of disadvantages:

  • Like most mechanical devices, they have a noticeable inertia - the delay in operation can be seen with the naked eye.
  • Carbon contacts wear out over time and need to be replaced.
  • The noise at work can barely be heard, but it's still there.

Before selecting an electromechanical voltage regulator, the response speed specified in the product pass must be compared in V / s units. The better this indicator, the better the stabilizer for sensitive instruments.

Electronic voltage regulators

Electronic stabilizers work a little differently. Feedback and switchover via Thyristor, seven-phase or relay circuitsThis will change the number of windings connected to the network. Such stabilizers work absolutely noiselessly, do not heat up and are characterized by a very high response speed. However, there were some disadvantages here: Electronic stabilizers regulate the output voltage gradually. While the differences are not too great, they can also affect the operation of electronics or motors.

Ferromagnetic voltage regulators

Ferromagnetic stabilizers are devices that are practically not made for domestic use, although there are still early models that were very popular decades ago. Their work is based on changing the position of the ferromagnetic core relative to the coils. The system is very reliable, but bulky and noisy. The main disadvantages are operation only under load and possible distortion of the sinusoidal properties. They are unsuitable for modern electronics and household appliances, but their use is quite acceptable for powerful electric motors, hand tools, and welding equipment.

Selection of a voltage regulator based on parameters

There are few really important parameters that characterize the stabilizer's performance and ease of use. The:

  • Number of phases;
  • Makes
  • Adjustment range;
  • Reaction speed;
  • Availability of overload protection;
  • Connection method.

Which voltage stabilizer to choose for a private house can only be solved by correctly depicting the scope of duties, taking into account the main features of the complex.

Network or trunk stabilizer

The connection method divides stabilizers into trunk and network. The first are installed at the entrance of the house's power supply and regulate the voltage that is supplied to all consumers, without exception - lighting, heating, alarm, household appliances. A modern house is usually a high-energy system with high electricity consumption. Therefore, the power of the main stabilizers starts at 3 kW.

Network regulators protect one, or more rarely two, devices of the same type. They are connected to a conventional socket and are an intermediate connection between the trunk and the consumer. Network stabilizers perform relatively poorly, but there can be several in the house.

These are relatively inexpensive devices that protect complex and expensive equipment when there is no main stabilizer or the load is very large. Network stabilizers are installed in residential buildings as well as in offices, hospitals and contact points where there are many high-precision electronic devices that are sensitive to voltage surges.

Number of stabilizer phases

One of the most important determining parameters in deciding which voltage regulator is best for a home. For a single-phase network, a stabilizer with a recommended voltage of 220V is required. There are three ways to solve the problem of three-phase current stabilization: buy three single-phase stabilizers, adjust each phase, install the stabilizer only on one phase to which the most sensitive loads are connected, and install a powerful three-phase voltage control device In the hole house.

You should know that most small and medium power household stabilizers are three-phase synchronized in a common housing. Three transformers mounted on a core are normally used for high power. They are more reliable and easier to set.

Makes

To understand how to choose a voltage stabilizer for a private house, it is necessary to know theoretically and practically exactly how much electricity is consumed in the house. The first digit is determined very easily - it arithmetically summarizes the performance of all consumers from the incandescent lamp to the borehole pump to the welding machine in the garage. This figure shows how much power is required for all devices that are switched on at the same time.

However, this display is not the upper limit - many tools and devices of household appliances are equipped with electric motors that consume much more electricity when started than when working even at maximum load. This so-called reactive power leads to a significant increase in total consumption.

The next step is to multiply the power of each device by an electric motor, indicated by 2 in kVA (indicated in the passport) and add the existing number. Then increase the result by another 25% in the event of unforeseen circumstances. After such difficult calculations, at a glance you can get the real performance of the stabilizer that needs to be installed in the house.

Power consumption (weight) of common industrial and construction machinery:


air conditioning
1000 - 3000 watts.

 
Circle machine.
1800-2100 W.

 
High pressure pump.
2000 - 2900 W.

 Jigsaw.
250 - 700 watts.


compressor
750 - 2800 W.


Electric motor
550 - 3000 watts.

 
Drill
400 - 800 watts.

 
Power planner.
400 - 1000 watts.


Circular saw.
750 - 1600 watts.


Water pump.
500 - 900 watts.


Hammer drill.
900 - 1400 watts.


Sander.
650 - 2200 watts.


Power consumption (W) of electrical household appliances:


TV
100 - 400 watts.


Toaster.
700 - 1500 watts.


fridge
150 - 600 watts.


water heater
1000-2000 watts.


Water heater.
5000 - 6000 watts.


Washing machine.
1800 - 3000 watts.


The coffee machine.
700 - 1500 watts.


Oven.
1000-2000 watts.


Computer.
400 - 750 watts.

Storage water heater.
1200 - 1500 watts.


iron
500 - 2000 watts.


Vacuum cleaner.
400-2000 watts.


microwave
1000-2000 watts.

Heater.
1000 - 2400 watts.


Electric lamp.
20 - 250 watts.

The average power of a three-phase stabilizer of a one-story house with a garage and a full range of household appliances hardly exceeds 10 kW. It's not that much and not too expensive. For a two-three-room apartment, 5 kW is enough, and for a two-story villa, a stabilizer of 15-25 kW is required.

However, when choosing a stabilizer in terms of performance, it is also necessary to pay attention to the range of current voltage settings. It should be within 150-250V. Only in this part of the line of possible deviations does the performance of the stabilizer correspond to the maximum indicated in the passport. If the manufacturer specified a larger range, for example 140-280 V - even better, your house will be protected more reliably. At the same time, however, the cost of the device increases slightly.

But price is not the main factor. Buying a stabilizer with a minimum setting range of, for example, 280-240V is not recommended, except as a network, if the house has a shared trunk. Such devices are not too expensive, but can only compensate voltage within narrow limits.

In special cases, when the deviations in the supply network can be more than 120 V (below), complex and expensive stabilizers are used, which can work in this area. As a rule, these are combined systems with electromechanical and electronic control that work in parallel. However, such a technique is seldom needed, so the average buyer has practically no interest in it.

Due to the performance in the list of each manufacturer, there are single-phase stabilizers up to 10 kVA and three-phase 5 - 30 kVA. Anyone who is not necessarily an electrician can choose them, focusing on the calculation method described above. It is not worth buying stabilizers with a capacity of 35-100 kVA for a house or summer residence. Intended for installation in office and shopping malls, workshops, and other high-power-consuming facilities, they are massive and expensive, and it is impractical to pay for excess electricity that is never used.

Output accuracy

No stabilizer delivers exactly 220 V. There are always differences in performance. State standards allow deviations of up to 10% in both directions. As a rule, even very sensitive devices such as inverters, computers and communication devices with such parameter distortions work quite reliably. Domestic consumers were originally designed for such deviations and did not cause any problems during operation.

According to the accuracy of the output voltage, the electromechanical stabilizers actually output 220 ± 3% V and the electronic stabilizers 220 ± 1% V, but then their response time is an order of magnitude, or even two, less. If the electronic regulator is able to change the output voltage for hundredths of a second, the electrician will spend 0.5 to 1 to 2 seconds on it.

Stabilizer protection systems

As with transformers, protection systems are required for all types of stabilizers. Their schematic representation and tasks are roughly the same, they are triggered when the supply current exceeds the permissible loads and disconnects the consumer from the grid. When the supply current returns to normal, the flow will automatically be restored.

The stabilizer also has its own effective protection system - it is a rather complex device with a mass of electronics that are sensitive to voltage and current overloads. A short circuit in the network can cause a large surge of electricity that can literally burn circuits.

The automatic protection system disconnects the primary winding and the adjustment system from the supply current in order to restore the normal parameters. The involvement of the stabilizer in the work is usually also carried out in automatic mode, but there are models with manual involvement after an emergency stop.

Additional functions and options

When choosing a voltage stabilizer for an apartment or house, one should not lose sight of a number of additional functions that simplify operation, increase safety and expand the functionality of the installation. It is often worthwhile to choose from two stabilizers with the same phase, power and the same setting range, one that offers more functions, even if it costs a little more.

Voltmeter and ammeter

Household stabilizers are optionally equipped with measuring devices (voltmeter required, ammeter). The devices show the output voltage after stabilization and the current strength in each phase. If you need to find out the voltage in the utility network, some stabilizers offer such an option - just press a special button and the voltmeter will switch to measure the input network parameters. Most household stabilizers are equipped with analog (pointer) voltmeters and ammeters with sufficiently high accuracy.

Recently, many manufacturers have switched from stabilizers to digital equipment - this significantly improves the design and, of course, allows you to increase the cost of installation. Although this does not have a major impact on the accuracy of the measurement, tenths and hundredths of the units of measurement do not play a special role in controlling the operation of a household stabilizer.

Many stabilizers are equipped with an LED alarm that informs about the normal operation of the device, exit from mode, critical overloads and other conditions of both the network and the device itself. Each of the manufacturers uses the number of LEDs and their color, what seems most convenient to them. Before starting the operation of the stabilizer, you need to familiarize yourself with the value of each lamp and the mode of operation - lighting, flashing and the frequency of flashes.

The stabilizers work in automatic mode and the possibility of manual adjustment is not provided. However, control devices have an important function: you can at any time determine the range of voltage and current deviations for each phase and turn off the consumer, which will not be able to work under these conditions, you can also visually check the total power output in the home network using the data from the control devices and the formula Taxes P =user interface.

The ability to switch the delay in the appearance of voltage at the output

Another convenient option is the output voltage delay button. This is necessary so that after stabilization all stabilizer circuits go into operation and supply the power with the required properties to the network. Normally it takes 5 - 7 seconds for the stabilizer to stand at home. If there is high power consumption in the home network, this time may not be sufficient. With the button you can extend it to several minutes and avoid possible false starts.

Bypass mode

It is very practical when the "bypass" function is available, ie conditions for the flow of direct current by bypassing all setting circuits and transformer devices. This is very convenient when the supply voltage is much lower than the allowable operating range or you need to connect a device that exceeds the critical level of the stabilizer in the power supply. In this case, the switch allows the electrical current to flow directly to the consumer, and the stabilizer is in standby mode.

Forced cooling fan

Stabilizers are cooled up to approx. 10 kVA by convection currents freely circulating through the ventilation openings in the housing. Higher power plants are equipped with external fans.

Features of installation and connection

As a rule, connecting stabilizers, especially mains and single-phase lines, is not difficult. Network controllers are plugged into a normal power outlet. The same sockets (one, two or more, depending on the power) are displayed in their housing, to which any device on a household level can be connected.

The trunk stabilizers are connected via a terminal block with 5 pins. Two - for the wires of the power network, two - for access to the home network and one for grounding (required). If you install the stabilizer near the entry point of the cable line in the house, then you can connect it yourself. However, you should turn off the main switch (switch). When live, it is extremely dangerous and not permitted to connect the device in accordance with the safety regulations.

After the meter, insert a stabilizer of any power. The three-phase stabilizer is equipped with a nine-pole block. The connection must be carried out by a qualified electrician with special tools. Installed stabilizers on the wall or on the floor, depending on the power and design.

As a rule, their operation is only permitted at positive temperatures and normal humidity. At T ≥ +40 0C The device's thermal protection can work. Therefore, the stabilizer should not be installed near heating equipment in places that are protected from direct sunlight.

Updated: September 26, 2018