Regulator selection, how to choose the regulator
1, the capacity factor of safety
AC power supply is output apparent power (kVA) for the nominal rated capacity, but under normal circumstances is not purely resistive load, that is the power factor COS ￠ ≠ 1, the Three Phase Transformer can output the actual active power kW = capacity (kVA) × COS ￠. So when the actual selection of electrical equipment according to the rated power, power factor and load types and other specific conditions to a reasonable choice power supply, the output power should be left right margin, especially when the margin impact load selection to be more specific selection of safety factors as follows:
Nature of the load factor of safety equipment, choose the type of power supply capacity
Incandescent purely resistive load, resistance wire, electric equipment 1.25 ~ 1.5 1.25 ~ 1.5 times the total power load
Inductive, capacitive load fluorescent lamps, fans, motors, pumps, air conditioners, computers, refrigerators, etc. 2 ~ 3 ≥ 2 ~ 3 times the total power load
Large inductive, capacitive loads (such as motors, computers) environment, the selection of the starting current of the load should be considered particularly large (up to the rated current of 5 to 8 times), so the choice should be the regulator load power capacity 2.5 to 3 times.
Such as: three-phase motor 2.2kW 1 units, 5.5 kW 1 sets, choice of Voltage Regulator Manufacturer, the capacity ≥ (2.2kW +5.5 kW) × 2.5 = 19.25 kVA, that is, at least to use more than LW-TNS20 kVA three-phase stability specifications pressure device.
2, non-compensated power supply output capacity curve
Auto-type regulators (single-phase 0.5kVA ~ 3kVA, 10k and below horizontal, three-phase 9kVA and below) when the input phase voltage is lower than 198V, the output capacity began to decline; input phase voltage equal to 160V, the drop to regulator rated capacity of 50%. Therefore, the supply voltage is reduced with particular attention to low load derating, so as not to overload the regulator burned;
Auto-regulator can simultaneously output two voltage 220V and 110V. But even when all the 110V output, the load carried by the regulator can not exceed the rated capacity of 50%, otherwise the overload use.