Surge Protectors

  Purpose of the voltage stabilizer (normalizer)

 

In houses and apartments today there are a large number of electrical appliances: heating boilers, computers, refrigerators, washing machines, microwave ovens, etc. All this electrical equipment is designed for power supply that meets the requirements of the Ukrainian standard - the voltage in the network must be 220 V ± 10%, that is, in the range from 198 V to 242 V. Imported equipment, and we primarily use imported equipment, designed for more demanding voltage ranges - in Europe, the permissible deviation from 220 V is 6%, that is, fluctuations from 207 V to 233 V are possible.
     
In our real life, voltage fluctuations go far beyond the standard. So in small towns and villages, the voltage in the evening drops to 150 V, and in some zones to 110 V. In other places where large industrial enterprises have disappeared, the voltage rises to 250-280 V during the day. At high voltage, electrical appliances can easily go out out of service. So the electronics of control systems for heating boilers and washing machines burn out at a voltage of more than 240 V. Even light bulbs burn out at 280 V. At low voltage, water pumps and refrigerator compressors burn out. If electrical appliances do not fail immediately, then the voltage non-compliance with the standards leads to a failure of microprocessor systems control programs, equipment operation in poor modes, and as a result to a significant reduction in the service life to 
40-45%. Voltage deviation from the norm leads to a significant (10-20%) increase in electricity consumption, the cost of which is constantly increasing.
     
Poor voltage is primarily indicated by ordinary lamps. At low voltage, they begin to shine dimly. Lowering the voltage at 10% reduces the brightness of the lamp at 40%. At high voltages, the lamps shine brightly and often burn out. This is the first sign of an abnormal stress level to be corrected in your home. To measure tension is necessary during the day and evening. During the day, the tension can increase greatly, and in the evening, on the contrary, it can fall. Having determined the voltage levels in the house, you will make an informed decision about purchasing a stabilizer. Voltage stabilizers can protect your devices from emergency voltage levels in the mains. They normalize the voltage in such a way that it is within strict limits. Expensive electrical equipment will serve for a long time and reliably if it is protected with a voltage stabilizer.

Choosing a voltage regulator

There are several things to consider when choosing a voltage regulator. You can install one powerful stabilizer, which will ensure operability and protect all electrical appliances in your house, apartment or office from voltage surges. In this case, you need a powerful device that provides 7-10 kW of consumption. This choice is quite justified in conditions when the house is located in an area of poor power supply.   If you need to protect only one device, for example, a heating boiler (they are very sensitive to an increase or decrease in voltage), then you will need a low-power 300 W voltage stabilizer. A 2 kW voltage regulator is sufficient for washing machines and most water pumps. Thus, when choosing a stabilizer, first of all, you need to evaluate the power of electrical appliances that require protection and the performance of which must be ensured in the first place.
      When evaluating the power of the device, the so-called inrush currents must be taken into account. Such currents arise when the pump, machine tool and other devices with electric motors are started. The engine at the moment of starting consumes 3-4 times more power than when operating in nominal mode. So, for example, heating boilers require a stabilizer, which is designed for a power of 300 W, although during operation the boiler pump consumes about 100 W.
    Thus, when you choose a stabilizer that will ensure the operation of one device, you need to take into account its power, taking into account the starting current (if any), and when choosing a stabilizer for the whole house, you must calculate the total power of all electrical appliances turned on at the same time.
   
After that, it is necessary to take a correction for a coefficient that depends on the voltage in the mains. These coefficients are shown in the table:
 

Voltage, V 130 150 170 210 220 230 250 270
Coefficient 1,67 1,47 1,29 1,05 1,00 1,05 1,29 1,47


If the total power consumption of your devices, taking into account the starting currents, is, for example, 6 kW, and the input voltage is at 130 V, then you need a stabilizer 6 kW x 1.69 = 10 kW. The same correction should be taken into account when choosing a stabilizer to protect one device.
     
In addition to the power of the stabilizer, one should take into account the speed - the response time of the device to voltage surges in the mains. There are stabilizers with a speed of 20 milliseconds, that is, the stabilizer will react to a voltage surge in 0.02 seconds. And there are inertial stabilizers that react in just a few seconds. So servo stabilizers normalize the output voltage at a speed of 10 V / s. With a sudden increase in the mains voltage, such a stabilizer will reduce the voltage at the output, which is dangerous for the device, for a long enough time (within a few seconds). During this time, the device may fail completely.
    
Stabilizers provide protection of electrical appliances from various limiting fluctuations in the electrical network. There are devices that start working from 160 V and there are those that operate from 110-130 V. There are stabilizers that turn off when the voltage rises to 250 V, and there are those that work reliably at 285 V. Thus, the oscillation range should be taken into account. voltage in the house and it is better to take a device with an appropriate operating input voltage range. Optimal stabilizers that will protect your device both from excessively low mains voltage, which burns the windings of motors and compressors, and from too high voltage, which destroys the electronics system. The necessary protection against too much power consumption, which will damage transformer stabilizer.

Protection systems that are necessary for the normal operation of the stabilizer.

Overcurrent protection is protection against excess power of the stabilizer by the consumer.
That is, if you have purchased a 5 kW stabilizer, then when you connect 6 kW consumers, protection against overpower (overcurrent protection) will work in the stabilizer. This protection can be implemented in two ways:
   
The stabilizer installed on a separate device has two types of current protection, an electronic and a fuse. The electronic protection must work after a pause in order to ignore the inrush currents, if the device and the fuse-link are designed for the presence of these inrush currents (this can be a boiler pump, refrigerator compressor or washing machine motor).
In the stabilizer installed in the whole house with current protection, there is a circuit breaker. Circuit breakers, as a rule, are not calibrated very clearly to certain values and allow some excess power for a short time. Some devices have overcurrents, mainly inrush currents of motors.
     
If the overcurrent (power) time does not exceed the automatic response time of the machine, then this overload impulse will be ignored. Therefore, if you are a little mistaken when choosing the power of the stabilizer, then the circuit breaker will allow some excess power.
    
High voltage protection is the ability of the stabilizer to lower the voltage when it exceeds the level of 240V. Oddly enough, there are many stabilizers that only increase the voltage to a certain level, and when the voltage in the network exceeds 240V, they pass it to the device. This may be suitable for those consumers who are confident that they have a stable undervoltage. But as practice shows, seasonal fluctuations in voltage can be both upward and downward. There are examples when the consumer's voltage did not exceed 180V throughout the winter, and with the arrival of spring, the voltage level increased to 260V!
    
The stabilizer must have a switching element (triac or relay) designed to turn off the consumer in the event of a breakdown of the stabilizer itself, in which the voltage at the output of the stabilizer may rise above 240V. This element can serve as an additional relay that does not participate in voltage stabilization, and therefore has minimal wear, which means it guarantees reliable shutdown in an emergency.
   
 Overheating protection (thermal protection).
Each stabilizer must be equipped with protection against transformer overheating. And also, if the switching elements are thyristors or triac, protection against their overheating must be provided. The quality of this type of protection is very important to prevent the stabilizer from catching fire, and therefore to prevent fire.

 

Voltage stabilizer speed

The speed of the voltage stabilizer should be understood as the reaction time of the stabilizer to a change in voltage in the network, or simply the time during which the stabilizer will work out the change in the input voltage and issue a stabilized voltage at its output. It is clear that the higher the speed or the lower the response time of the stabilizer, the better. Since the speed of the stabilizer determines the time during which the unregulated mains voltage will be applied to your devices. In terms of speed, servo stabilizers lose their speed of regulation, which fluctuates between 15-150 V / sec. Electronic (compensation, discrete) voltage stabilizers have the highest performance. Electronic stabilizers regulate the voltage by switching the windings of a special autotransformer with electronic keys. The keys are controlled by a microprocessor using a special program. Two types of electronic voltage stabilizers are produced: with semiconductor (thyristors or triac) and relay switches. Stabilizers of this type have high performance, therefore, they are installed in conjunction with expensive equipment, which requires protection from all network anomalies. They are also used in homes and industries.. Under the speed of such stabilizers, it is necessary to understand the time of measuring the voltage in the network plus the response time of the switching element (thyristor or relay). For a reliable estimate of the mains voltage, measurements will be required for 20 ms (one sinusoid period). The switching time of the thyristor, triac and low-power relays does not exceed 10ms, for high-power relays (for stabilizers from 5 kW to 10 kW) does not exceed 20ms. Therefore, the speed of triac (thyristor) voltage stabilizers can be equated to the speed of relay.

Three-phase stabilizers

Three-phase stabilizers combination three single-phase stabilizers, which collected v one or v three various buildings. At connecting To electrical grid each one from phases connects to one of three stabilizers. So way provided stabilization of all three phases. Technical specifications three-phase stabilizers completely identical characteristics single-phase stabilizers, which are described v relevant section(see above).

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