A voltage stabilizer is a device that stabilizes the output voltage. It is composed of a voltage regulating 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 change the position of the carbon brush of the voltage regulator. The coil turns ratio is automatically adjusted to keep the output voltage stable.
The role of voltage stabilizer
A voltage stabilizer is a power supply circuit or power supply device that can automatically adjust the output voltage. Its function is to stabilize the power supply voltage that fluctuates greatly and does not meet the requirements of electrical equipment within its set value range, so that various circuits or electrical appliances The equipment can work normally under the rated working voltage.
The original power regulator relied on the jump of the relay to stabilize the voltage. When the grid voltage fluctuates, the automatic correction circuit of the power regulator is activated to activate the internal relay. Forcing the output voltage to remain near the set value, this circuit has the advantage of simple circuit, 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 reading and writing work of computer equipment, and it is easy to cause wrong signals on the computer, and in severe cases, it will damage the hard disk. High-quality small voltage stabilizers mostly use the method of motor-driven carbon brushes to stabilize the voltage. This type of voltage stabilizer has little interference to electrical equipment and has relatively high voltage stabilization accuracy.
Working principle of voltage stabilizer
Because some electrical appliances contain coil components, eddy currents that hinder the current will be generated at the initial stage of power-on. The generation of eddy currents will not only weaken the instantaneous voltage when the appliance is started, resulting in slow startup, but also strengthen the instantaneous voltage generated after the circuit break, which may cause spark damage Circuit. At this time, a voltage regulator is needed to protect the normal operation of the circuit.
The voltage stabilizer is composed of a voltage regulating 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 to change the position of the carbon brush of the voltage regulator. By automatically adjusting the coil turns ratio, the output voltage is kept stable. The voltage regulator with larger capacity also works on the principle of voltage compensation.
Power of voltage stabilizer
1. The marked output power of the voltage stabilizer is the maximum power. The nominal power of household appliances refers to active power, while inductive loads such as refrigerators, air conditioners, and water pumps have a large current at the instant of starting. Therefore, refrigerators, air conditioners, and water pumps are rated at power × (3 to 5 times).
For example: 3 hp beautiful air conditioner (220V electricity)
1 horse is equal to 0.75 kilowatts x 3 horses = 2.25 kilowatts x 3 times the load starting current = 6.75 kilowatts and above, the voltage regulator is applicable. (Midea maintenance technician recommends 8KVA voltage stabilizer)
2. Use power algorithm by professional hydropower installation technicians and factory professional electricians, engineers and voltage stabilizers: general industrial equipment should be multiplied by the rated power by at least 2 times the power used, when used in equipment with motor running equipment, large current starting devices and impact When it is installed on a sexual load device, a voltage stabilizer with a capacity of more than 3 times should be selected to avoid excessive starting current and voltage drop of the power supply line and fail to work normally.
For example, a certain factory's steam pump (380V electrical equipment) has a motor power of 7.5 kW, but when it starts to operate, the surge current exceeds 3 times the motor power, so it must be selected to be more than 3 times its power Voltage regulator.
3. When the output voltage of the 0.5KVA-3KVA voltage stabilizer is 110V, the input capacity cannot exceed 40% of the rated capacity. When the output end requires 110V and 220V to be used at the same time, the output capacity should be 50% of the rated capacity to avoid overload.
Points for purchasing voltage stabilizer
It is recommended that you buy a voltage stabilizer that is at least three times larger than the actual power, because the voltage stabilizer has to overcome the surge impact of the mains and the starting impact of the inductive load (such as refrigerators, air conditioners, motors and motors) in actual work.
1. When the voltage stabilizer is used in an inductive load, because the inductive load has a large instantaneous starting current, it is generally about 3 to 5 times the rated current and often exceeds 9 times the operating current (such as refrigerators, air conditioners, washing machines, electric fans, Large-scale air conditioners, printing machines, air compressors, elevators, water pumps, etc. are all inductive loads), so any voltage stabilizer equipped with inductive loads such as motors, compressors and electrical appliances must consider its power reserve and leave a margin. It is necessary to reserve enough margin to avoid immediate damage to the regulator 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 the high-power inductive load starting at the same time. Therefore, when purchasing a voltage stabilizer, there should be 1.5 times the reserved capacity for a single machine. 3 times.
2. Pay attention to whether the voltage value of the mains power supply exceeds the input voltage range specified by the voltage stabilizer purchased, and whether the three-phase 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 regulator needs to reserve expansion capacity
4. Regardless of whether it is a single machine or a whole plant, a certain reserved capacity should be reserved for the purchased voltage stabilizer to avoid a 100% load rate of the voltage stabilizer. The load rate of the voltage stabilizer is generally 90%. . The shape and structure of the automatic voltage regulator are desktop, wall-mounted, counter-wall dual-purpose and floor-standing. Different styles should be selected according to the installation location, main purpose, and installation capacity.
5. Industry insiders reminded that when choosing a voltage regulator, you should also pay attention to choosing products with high brand awareness, because these manufacturers have reliable quality and good service; at the same time, whether the manufacturers have good after-sales services, such as product quality implementation of three guarantees, etc. It is also an important factor that consumers should pay attention to.
Voltage stabilizer usage specification
1. Connect to the mains (according to the national standard for left-zero and right-fire wiring)
①The input wire diameter of the access device must be ≥25mm2 copper core wire
②The input and output line clamp screws of the access device must be tightened
③The input and output wires must not be connected in reverse
④The front end of the equipment cannot replace the air switch with a leakage protector
2. Access load
The load power cannot exceed the maximum power of the stabilized power supply: for example: 50KVA. The general load rate is 50KVA×0.8=40KW
①All the 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 stabilized power supply (it is strictly prohibited to turn on the load first, and then turn on the stabilized power supply)
① Please make sure that the stabilized power supply is turned on when the computer monitor is off.
②Measure the input voltage before turning it on and it should be between 304V and 456V.
③Check that the output voltage meter that comes with the machine should be 380V.
4. Don't use too high load;
5. Please use enough wires;
6. Please carefully connect the input voltage and the output of the equipment;
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. To use the same rated fuse, not non-rated fuse or wire;
11. Install in a dry and ventilated place.
Voltage stabilizer maintenance
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-adjustable type, high-power compensation type, switch type and other types.
The daily maintenance of the voltage stabilizer should pay attention to 4 points:
1. The voltage stabilizer should be placed in a ventilated, dry, non-direct sunlight, non-corrosive gas indoor use;
2. The selected power of 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. The voltage stabilizer switch should be turned on first. After the power is output, connect different electrical equipment from small to large in order, and from large to small when shutting down. Shut down, and finally turn off the voltage regulator switch;
4. The switch of the voltage stabilizer should not be turned on frequently, and the time interval between each opening should be greater than 10 seconds, otherwise it is easy to cause false protection of the voltage stabilizer or even damage.