潜水电泵远距离起动所需电缆面积的确定

对于大中型高扬程的潜水电泵,连接潜水电泵与变压器之间的电缆较长,在电缆面积一定时,电缆的电阻随长度的增加而增大,电阻产生的压降大于一定值时,加在电泵上的电压将低于电泵的起动电压,电泵无法正常起动.通过对潜水电泵起动转矩、起动电流、起动电压的分析、计算,推导出远距离连接后能正常起动所需电缆许用最小面积的计算公式,并用一些经验值代入后得到一个实用的算式,在电缆面积给定的情况下计算出允许连接的最大长度.计算结果表明,电缆的许用最小面积与电泵额定电流IN和电缆长度L成正比,与电泵额定电压UN成反比.该结论同样适用于与离心泵配套的普通电机远距离连接.

Deciding the area of cable for starting submersible motor pump in condition of far distance between the transformer and motor

In condition of far distance between the transformer and submersible motor pump, it needs a long cable to connect the both, which causes a large voltage drop and thus leads to unsuccessful submersible motor start. By analyzing the start torque, start current, and start voltage, we derived formulas to calculate the needed minimum area of cable and to calculate the maximum length of cable at certain area of cable for normally starting the motor. The example is given out to illustrate that the needed minimum area of cable is in proportion with rated current IN, the length of cable L, and inverse proportion rated voltage UN. These formulations can also be applied when connecting general motor with centrifugal pump.