Category:power

Question:
received from the transformer out of a four-core cable to the distribution after-hours, when measured using the table for every roots and power strips connected to the shell does
disk from the distribution of this power transformer 5 yes m long cable line is a new line, what were the reasons for

Answer:
it is because the internal wiring have spoken three-phase transformer windings required to connect your switchboard to protect the shell of possible grounding or receive a zero It is naturally every roots and power strips connected to the shell (you use the table when the actual measurement is the measurement transformer winding resistance of each phase, due to low voltage transformer winding resistance is very low, the measurement results are also similar to short-circuit a), to be to obtain accurate measurement results, should be connected to the transformer to measure the line disconnected.

Answer:
This is because you use the transformer secondary is a star-wiring method, star-point line received a disk case, measurement is the heart’s natural, and if you want to measure the insulation of transformer coil and shell, please take the star point on or after the star point insulation can be measured, measurement to complete restitution,

Chinese:为什么对壳

类别: 电力

问题:
从变压器接出一根四芯电缆接到配电盘后用表测时每根都和 配电盘壳相连呢
这个动力配电盘离 变压器 五是米远 电缆线是新线请问是什么原因

回答:
那是由于变压器内部接线已讲三相绕组按要求连接起来,你的配电盘壳可能进行了保护接地或接零,那自然是每根都和 配电盘壳相连了(你用表测时实际测量的是变压器内部绕组每相的电阻,由于变压器低压绕组的电阻很低,测量结果也就近似是短路了),要获得准确的测量结果,应该将接在变压器上的线路断开进行测量.

回答:
这是因为你用的变压器二次是星形接线法，星点线接到盘的外壳，测量自然就是相通的了，如果你要测变压器线圈与外壳的绝缘，请把星点取开或将星点绝缘后进行测即可，测量完成恢复原状，