Influence on power distribution panel and low voltage lines (1) the three-phase unbalanced load will increase the loss of line: Three-phase four wire power supply line, the load average assigned tothree phase, with current per phase is I, the neutral line current is zero,the power loss is: Δ P1 = 3I2 The maximum unbalance, namely, a phase of 3I, the other two are zero,the neutral line current is 3I, the power loss is: Δ P2 = 2 (3I) 2R = 18I2R = 6 (3I2R) The maximum unbalance power loss is 6

When changing the connection of one stator winding, magnetic pole rotating magnetic field generated is changed. This method of variable pole speed only applies to three-phase cage induction motor, does not apply to the wound rotor asynchronous motor. Because the number of poles of cage rotor of the motor can be changed with the stator pole number changes, while the rotor winding rotor motor in rotor winding has been determined the number of pole pairs, in general it is difficult to change the nu

Influence on power distribution panel and low voltage lines (1) the three-phase unbalanced load will increase the loss of line: Three-phase four wire power supply line, the load average assigned tothree phase, with current per phase is I, the neutral line current is zero,the power loss is: Δ P1 = 3I2 The maximum unbalance, namely, a phase of 3I, the other two are zero,the neutral line current is 3I, the power loss is: Δ P2 = 2 (3I) 2R = 18I2R = 6 (3I2R) The maximum unbalance power loss is 6

When changing the connection of one stator winding, magnetic pole rotating magnetic field generated is changed. This method of variable pole speed only applies to three-phase cage induction motor, does not apply to the wound rotor asynchronous motor. Because the number of poles of cage rotor of the motor can be changed with the stator pole number changes, while the rotor winding rotor motor in rotor winding has been determined the number of pole pairs, in general it is difficult to change the nu

Effects of high voltage line (1) increase the high voltage line loss: Low voltage three-phase load balance, 6 ~ 10K high voltage side Vbalance, a high voltage line the current in each phase is I, the power loss is: Δ P1 = 3I2 Low voltage three-phase unbalanced load will be reflected in the high side,the maximum unbalance, voltage corresponding to 1.5I, the other two are 0.75 I, power loss: The Δ P2 = 2 (0.75I) 2R + (1.5I) 2R = 3.375I2R =1.125 (3I2R) The high-pressure line energy loss increas

Rolling bearing assembly method used should be the size and the amount of interference to choose. General bearing assembly methods are hammering method, using screw or lever presses pressed into France and thermal loading method. But in any case, can not knock the bearing ring, cage, rolling bodies or the sealing member. Deep groove ball bearing assembly methods are hammering common law and pressed into law. Small motors are generally used push method, using a direct bearing mounting pressed in

Impact on distribution transformers ( A ) three-phase unbalanced load will increase transformer losses : Transformer load loss and load loss including loss . Under normal circumstances the operating voltage transformer basically unchanged, ie no-load loss is a constant. While the load loss of the operation of the transformer with the load change, and the square of the load current Proportional . When the three-phase unbalanced load operation, the transformer load loss can be viewed as three s

Uvw in positive sequence phase AC motor clockwise access u-phase, v-phase, w-phase winding, a magnetic field generated thereby is turning clockwise (ie, winding by the current phase advance current phase shift backward winding ), if any exchange connected to the motor winding two-phase alternating current phase sequence, such as the u-phase alternating current winding is still connected to the u-phase, v-phase winding is connected to the w-phase AC, w-phase winding connected v-phase alternating

The use of electrical insulation products to a variety of factors (such as temperature, electrical and mechanical stress, vibration, harmful gases, chemicals, moisture, dust, and irradiation, etc.) effects, and the temperature usually is the aging of insulation materials and dominant factor. A practical result has been recognized worldwide as the heat resistance classification method, that is, the heat resistance of the electrical insulation is divided into several heat levels. Motor insulation

Pumps, fans, class load, the frequency can be adjusted to control the motor's power output to achieve energy-saving systems.Pump operating point is determined by the pump head curve and line resistance characteristic curve intersection. P = QH (P power, Q flow, H pressure head) (as A ') 3, the power of the operating point of the area enclosed by the curve. The traditional water flow through the valve to adjust. This method is by increasing the pipeline resistance characteristics. Althou