Technical requirements for supporting cables for deep well submersible pumps

Deep well submersible pump with the power cable specifications by the cable heating and voltage drop of two factors. In addition to the need to control a certain current density to limit the cable temperature rise, the longer the cable length, the greater the voltage drop of the cable, the motor starting performance, operating performance and reliability of the greater impact. Therefore, for the same well with a submersible motor, when equipped with a deep well submersible pump head is different, with cable length is different, require the cable section is not the same. In accordance with the "well with submersible pumps" standard requirements, the water temperature is 25 ℃, the current rating, the cable voltage drop should not exceed 5% of the rated voltage. This can be obtained when the power supply voltage is 380V, different power wells with submersible motor with a certain size of the cable when the maximum allowable length. When the grid supply voltage is high and stable or the supply transformer capacity is relatively large, the voltage is high, more stable, the well with the submersible motor with the specifications of the cable length can be appropriate to extend the specific circumstances (or The cable section with the appropriate reduced to reduce the cost of cable configuration).
    When the deep well submersible pump head high, deep down the motor, with a long cable length, and poor quality of the transformer power supply, the motor is very difficult to start: very large starting current, long cable voltage drop great, the motor terminal voltage Reduce a lot of starting current to further increase the cable pressure drop more lower starting torque, resulting in a vicious cycle, not only the motor starting difficult, forced start may cause damage to the motor winding burned.