I believe everyone is not very familiar with the voltage stabilizer, but it plays a very important role in our home. It can automatically adjust the output voltage of the power supply equipment, so that the unstable power supply voltage with large fluctuations can be stabilized within the corresponding range, so that various circuit electrical equipment can work stably under normal voltage. In this topic, I will explain the theodolite knowledge in detail for you.
1 What is a voltage regulator
A voltage regulator is a device that stabilizes the output voltage. The voltage stabilizer is composed of a voltage regulation circuit, a control circuit, and a servo motor. When the input voltage or load changes, the control circuit performs sampling, comparison and amplification, and then drives the servo motor to rotate, so that the position of the carbon brush of the voltage regulator changes, and the coil turns ratio is automatically adjusted to maintain the stability of the output voltage.
2 The role of the voltage stabilizer
The voltage stabilizer is a power supply circuit or power supply equipment that can automatically adjust the output voltage. Within the range of the set value, various circuits or electrical equipment can work normally under the rated working voltage.
The original power regulators relied on the bounce of relays to stabilize the voltage. When the grid voltage fluctuates, the automatic correction circuit of the power regulator is activated to make the internal relay operate. Forcing the output voltage to remain near the set value, the advantage of this circuit is that the circuit is simple, but the disadvantage is that the voltage regulation accuracy is not high, and every time the relay jumps and shifts, it will cause an instantaneous interruption of the power supply and spark interference.
This greatly interferes with the read and write work of computer equipment, and it is easy to cause error signals in the computer, and in severe cases, the hard disk will be damaged.
The high-quality small voltage stabilizer mostly adopts the method of dragging the carbon brush by the motor to stabilize the voltage. This kind of voltage stabilizer has little interference to the electrical equipment, and the voltage stabilization accuracy is relatively high.
3 The working principle of the voltage stabilizer
Since some electrical appliances contain coil components, eddy currents that hinder the current will be generated at the initial stage of electrification. The voltage will lead to slow start, and it will strengthen the instantaneous voltage generated after the circuit breaker, which may cause sparks to damage the circuit. At this point, a voltage regulator is needed to protect the normal operation of the circuit.
The voltage stabilizer is composed of a voltage regulation circuit, a control circuit, and a servo motor. When the input voltage or load changes, the control circuit samples, compares, and amplifies, and then drives the servo motor to rotate to make the voltage regulation. The position of the carbon brush is changed, and the coil turns ratio is automatically adjusted to maintain the stability of the output voltage. The voltage stabilizer with larger capacity also works on the principle of voltage compensation.
4 Voltage stabilizer power
1. The output power marked by the voltage stabilizer is the maximum power. The nominal power of household appliances refers to the active power, and inductive loads such as refrigerators, air conditioners, and water pumps have a large current at the instant of startup, so refrigerators, air conditioners, and water pumps are calculated by power × (3 to 5 times).
For example: 3 hp Midea air conditioners (220V electricity)
1 hp equals 0.75 kW x 3 hp = 2.25 kW x 3 times the inductive load starting current = 6.75 kW or more voltage regulator device is applicable. (The 8KVA voltage stabilizer is recommended by the maintenance technicians of Midea)
2. Use the power algorithm of professional water and electricity installation technicians and professional electricians, engineers and voltage stabilizers in the factory: for general industrial equipment, multiply the rated power by at least 2 When used on equipment with motor running, high current starting device and impact load equipment, a voltage stabilizer with a capacity of more than 3 times should be selected to avoid excessive starting current and power supply line voltage drop and cannot work normally .
For example: a steam pump (380V electrical equipment) in a factory has a motor power of 7.5 kW, but when it starts to run, the surge current exceeds three times the motor power, so A voltage regulator must be chosen that is 3 times larger than its power.
3. When the output voltage of 0.5KVA—3KVA voltage stabilizer is 110V, the input capacity cannot exceed 40% of the rated capacity. When the output terminal needs to use 110V and 220V at the same time, the output capacity should be within the rated capacity. 50% to avoid overload.
5 Voltage stabilizer purchase
When purchasing a voltage stabilizer, it is recommended that you at least purchase a voltage stabilizer that is three times larger than the actual power, because the voltage stabilizer is In actual work, it is necessary to overcome the surge shock of mains and the starting shock of inductive loads (such as refrigerators, air conditioners, motors and electric motors).
1. When the voltage stabilizer is used in an inductive load, due to the large instantaneous starting current of the inductive load, it is generally about 3-5 times of the rated current and often exceeds 9 times of the running current (such as refrigerators, Air conditioners, washing machines, fans, large air conditioners, printing presses, air compressors, elevators, water pumps, etc. are all inductive loads), so any voltage stabilizer equipped with inductive loads such as motors and compressors must consider its power reserve. , To leave a margin, it is necessary to reserve enough margin to avoid immediate damage to the voltage stabilizer caused by the inrush current generated when the load is turned on. If the whole plant uses a voltage stabilizer, when starting the machine, avoid high-power inductive loads from starting at the same time, so when purchasing a voltage stabilizer, there should be 1.5 times the reserved capacity. 3 times.
2. Pay attention to the voltage value of the mains power supply, whether it exceeds the input voltage range specified by the selected voltage stabilizer, and whether the three-phase power voltage differs by more than 10V
3. Before purchasing a machine, it is necessary to consider future business expansion, whether it is necessary to increase equipment, and whether the voltage stabilizer needs to reserve expansion capacity
4. Whether it is a stand-alone package or a complete plant, the purchased voltage stabilizer should be It is more appropriate to reserve a certain reserved capacity to avoid the 100% load rate of the voltage stabilizer. The load rate of the voltage stabilizer is generally 90%. The shape and structure of automatic voltage regulators include desktop, wall-mounted, table-wall dual-use and floor-standing. Different styles should be selected according to the installation location, main purpose, and installation capacity.
5. Industry insiders remind that when choosing a voltage stabilizer, you should also pay attention to choosing products with high brand awareness, because these manufacturers have reliable quality and considerate service; at the same time, do manufacturers have good after-sales service, such as The implementation of three guarantees for product quality is also an important factor that consumers should pay attention to.
6 How to use the voltage stabilizer
1. Connect to the mains (according to the national standard for left-zero and right-fire wiring)
①The diameter of the input wire of the access device must be ensured ≥ 25mm2 copper core wire
②Connect the input and output wires of the device to the input and output wires must be tightened
③The input and output wires must not be reversed
④The front end of the device The leakage protector cannot be used to replace the air switch
2. Access to the load
The load power cannot exceed the maximum power of the regulated power supply: example: 50KVA. The general load rate is 50KVA×0.8= 40KW
①All line interfaces of the output line must be connected tightly, otherwise the line will heat up due to the large current, which will affect the effective power.
3. Turn on the regulated power supply (it is strictly forbidden to turn on the load first, then turn on the regulated power supply)
① Please ensure that the computer monitor is turned off and the regulated power supply is turned on.
②Before turning on, measure the input voltage value should be between 304V-456V.
③ Check that the output voltmeter that comes with the machine should be 380V.
4. Do not use excessive load;
5. Please use enough wires;
6. Please be careful to connect the input voltage and the Output;
7. The output voltage of the equipment and the voltage stabilizer should be unified;
8. Please select the input voltage switch to be the same as the power supply voltage;
9. If the fuse is burned out, please check the load equipment;
10. Use the fuse of the same rating, and do not use non-rated fuses or wires;
11. Install it in a dry and ventilated place place.
7 Voltage Stabilizer Maintenance
A voltage stabilizer is a device that provides stable output voltage according to the requirements of electrical equipment. There are mainly intelligent numerical control type, auto-coupling adjustment type, high-power compensation type, switch type and so on.
The daily maintenance of the voltage stabilizer should pay attention to 4 points:
1. The voltage stabilizer should be placed in a ventilated, dry, no direct sunlight, no corrosive gas indoor use;
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2. The power selected by the voltage stabilizer should be greater than the total power of the electrical equipment;
3. The voltage stabilizer switch should not be used as the main switch of the equipment, and the voltage stabilizer switch should be turned on first , after the power supply is output, then connect different electrical equipment in order from small to large, shut down from large to small when shutting down, and finally turn off the switch of the voltage stabilizer;
4. Voltage stabilization The switch of the regulator should not be turned on frequently, and the time interval of each turn on should be greater than 10 seconds, otherwise it will easily cause the false protection of the voltage regulator, or even damage.
8 What is the reason why the voltage stabilizer is not regulated
First, the voltage is too high and needs to be stepped down; when the input voltage is much higher than the rated voltage carried by the voltage stabilizer equipment, it will lead to voltage stabilization The equipment fails, so the voltage is unstable;
Second, the overvoltage protection circuit; after the overvoltage protection, the LED light-emitting tube lights up, resulting in power failure;
Third, Undervoltage protection circuit; the voltage is low, and the adjustment through the voltage regulator is still not within the range (below 220V), which eventually leads to the release of the relay, even if there is a diode, it will work at this time, so the voltage is unstable.
Fourth, the sampling voltage and the reference voltage; the rule for connecting the sampling voltage and the reference voltage to the input terminal of the voltage comparator is: to detect whether the output voltage of the computer voltage stabilizer is higher than the rated value of 220V, and its positive input terminal is connected Sampling voltage, the negative input terminal is connected to the reference voltage.
Fifth, the voltage is low and needs to be boosted; if the input voltage is too high or too low, the motor drags the carbon brush to the limit position and still cannot make the output voltage return to 220V, the carbon brush holder The limit switch will be touched, and the motor will be powered off and stopped to avoid overload damage to the motor.
Sixth, the power-on delay time interruption control; until the power-on delay ends. This process takes about 5 minutes. Power on delay is mainly to protect the power safety of air conditioners, refrigerators and other equipment. If there is no such requirement, you can press the quick-start self-locking button AN, and the power-on delay time will be shortened to 2~3 seconds. The main purpose of power-on delay power transmission is to protect the power safety of the circuit.
