Most users in life are no strangers to voltage stabilizers, and their main function is to stabilize the output voltage. One of the most common is the 220V stabilizer. The 220V voltage stabilizer is composed of a contact auto-voltage stabilizer, servo motor, automatic control circuit, and so on. And it can stabilize the output voltage at 220V according to the change of voltage. Next, ATO will share with you in detail how to choose the power of the voltage stabilizer.
The voltage stabilizer takes the output apparent power (kVA) as the nominal rated capacity, and in general, the load is not purely resistive, that is, the power factor cos Φ ≠ 1, the actual output active power of the voltage stabilizer kW = capacity (kVA) x cos Φ. Therefore, in the actual selection, the regulated power supply should be reasonably selected according to the specific conditions of the rated power, power factor, and load type of the electrical equipment, and its output power should have an appropriate margin. Especially in the selection of impact loads, the margin should be larger.
The specific selection safety factor is shown in the following table:
| Load | Equipment Type | Safety Factor | Voltage Stabilizer Capacity |
| Pure resistive load | Incandescent lamp, resistance wire, electric furnace | 1.25~1.5 | 1.25~1.5 times the total load power |
| Inductive, capacitive load | fluorescent lamps, fans, motors, pumps, air conditioners, computers, refrigerators | 2~3 | 2~3 times the total load power |
In the environment of large inductive and capacitive loads (such as motors, computers), the starting current of the load is large (up to 5~8 times of the rated current), so the capacity of the three-phase voltage stabilizer should be 2.5~3 times the load power.
- The output power marked by the voltage stabilizer is the maximum power. Basically, most of the nominal power of household appliances refers to active power, and most of the refrigerators, air conditioners, and those pumps used in the home are also inductive loads, and the current is very large at the moment of a startup. Therefore, the selection of matching voltage stabilizers for refrigerators, air conditioners, and water pumps should be calculated according to the power x 3~5 times.
- In most cases, industrial equipment selects the voltage stabilizer according to the rated power multiplied by at least 2 times or more. Moreover, if it is used on equipment with the motor operation or on high-current starting devices and impact load equipment, it is recommended to choose a voltage stabilizer with a capacity of more than 3 times, so as to be able to start the current as soon as possible. If it is too large, the power supply line is stepped down and cannot work normally.
- If it is a 0.5KVA-10KVA voltage stabilizer device when choosing its output voltage of 110V, it is recommended that the input capacity should not exceed 40% of the rated capacity, and if it is at the output end, then it is necessary to When 110V and 220V are used at the same time, the output capacity should be 50% of the rated capacity to avoid overload.
The output capacity of the uncompensated regulated power supply is an auto-coupled voltage stabilizer (single-phase 0.5kVA~3kVA version, 10kVA horizontal version and below, three-phase 9kVA version and below), when the input phase voltage is lower than 198V, the output capacity begins to drop. When the input phase voltage is equal to 160V, it drops to 50% of the rated capacity of the regulator. Therefore, at the low end of the power supply voltage, special attention should be paid to reducing the load and derating to avoid overloading and burning the regulator; the auto-voltage stabilizer can output two voltages of 220V and 110V at the same time. But even if it is all output by 110V, the load of the voltage stabilizer cannot exceed 50% of the rated capacity, otherwise, it is overloaded.