EI Lamination Silicon Steel Transformer Core

EI Lamination Silicon Steel Transformer Core

China Manufacturer High Quality Custom sized silicon steel transformer core

Temporary exclusion method when the transformer cannot be stopped:
① There is an external ground wire. If the fault current is large, the ground wire can be temporarily opened for operation. But the monitoring must be strengthened to prevent the floating potential of the iron core after the fault point disappears.
②If the multi-point grounding fault is unstable, a sliding wire resistance can be inserted in the working grounding wire to limit the current to less than 1A. The selection of the sliding wire resistance is to divide the measured voltage of the normal working ground wire by the current on the ground wire.
③ Chromatographic analysis should be used to monitor the gas production rate at the fault point.
④ After finding the exact fault point through measurement, if it cannot be handled, the normal working grounding piece of the iron core can be moved to the same position of the fault point to reduce the circulating current to a greater extent.
(2) Thorough maintenance measures. After the monitoring found that the transformer has a multi-point ground fault, the transformer that can be shut down should be shut down in time, and the multi-point ground fault should be completely eliminated after exit. To eliminate such faults, according to the type and cause of multi-point grounding, corresponding maintenance measures should be taken. However, there are also some cases where the fault point cannot be found after the power is suspended. In order to find the ground point exactly, the following methods can be used on site.
①DC method. Open the connecting piece of the iron core and the clamping piece, pass 6V DC on the silicon steel sheets on both sides of the yoke, and then measure the voltage between the silicon steel sheets at all levels in sequence with a DC voltmeter. When the voltage is equal to zero or the meter indicates reverse, then It can be considered as a fault ground point.
② Communication method. Connect the low-voltage winding of the transformer to the AC voltage 220 ~ 380V, at this time there is magnetic flux in the iron core. If there is a multi-point ground fault, current will be measured with a milliampere meter (the connection piece between the iron core and the clamp should be opened). Use a milliampere meter to measure point by point along all levels of the iron yoke. When the current in the milliampere meter is zero, this is the fault point.