This 400kVA resin cast dry-type transformer has been completed and is ready to be delivered to China.
Dry-type transformer production process:
Our dry-type transformers need to be designed before manufacturing, and when confirming the transformer design, we need to pay attention to the winding and insulation. First confirm whether the drawing is consistent with the production product and confirm that the capacity is correct before looking at the wire gauge. Once you find the wire gauge, confirm the number of turns. Secondly, confirm the wiring method. High-voltage stretching depends on the tap outlet, number of tap turns, low-voltage winding method, tap outlet length, transposition position, winding inner diameter and outer diameter, amplitude direction, etc. Secondly, calculate the length and width of the paper tube cardboard according to the inner diameter of the coil, and then find out the end insulation length diagram from the drawing number, including the thickness of the oil circuit pad and the corrugated oil channel, and then find out the end ring and the upper and lower iron brackets in turn. insulation.
The second part is the starting side winding and insulation. Check the drawing to confirm the length of the machine head. If it is a spiral type, a different scale is required. The latter group measures one more length of wire than the previous group to keep the head neat and nice. After bending the head, wrap it with a layer of corrugated paper with the same arc angle. After the head is completed, wrap it with corrugated paper with a thickness of 3mm and tie it tightly with white cloth tape (without a tight tape, it will be easily burned during welding).
Before rolling the paper tube, use a caliper to measure the outer diameter of the mold and cut out the cardboard that needs to be padded with paper. It is best to use one millimeter for paper tube cardboard. Overlap the ends and wrap tightly with tight tape. When winding, the auxiliary worker should hammer along the tight belt to tighten it.
When the end insulation of the cylindrical winding method is paper strips, tie it with a straight cloth tape on the first turn of the wire and start winding the first turn. When winding, tighten the tape four times along the circumference of the wire (tight tape). The end insulation is tied into a figure-8 shape. Tight fabric tape ties the first turn and end insulation together. When winding the second round, turn the tight tape upwards, and when winding the third round, press down to tighten the end ring in a zigzag shape. The cylindrical winding is transposed once in the middle. After transposition, wrap it with a layer of corrugated paper, a half-millimetre-thick cardboard pad inside, and tie it tightly with white cloth tape. Auxiliary personnel should adhere closely to and control the amplitude direction. Three layers of 0.08mm cable paper should be used to insulate the layers. The second turn of the outgoing wire should be separated by half a millimeter thick cardboard to avoid damage to the insulation. When removing the bottom layer, also add it at the scissor edge.
Finally, the two early ends should align. Likewise, the earliest end and the penultimate turn should be separated by cardboard, and the two earliest ends should be tied tightly. Tighten the entire coil with tight tape before cutting the wires.
Spiral windings are mainly low-voltage windings above 630kVA, and their heads are the same as cylindrical windings. It should be noted that the curved part of the machine head is compressed with a diagonal tension belt as the front tensioning cloth strap, and is pressed to the end of the machine head and tied to prevent the machine head from popping out and coil tension.
