ChinSun Bushing Terminal

Cold-pressing connection method for transformer high-voltage draw lead

The Cold-pressing method for connecting the high-voltage lead of the transformer is to drive a pair
of pressing dies to move relative to each other through an electric hydraulic plier, so that the dies
squeeze the cold-pressed tube, and use the deformation of the cold-pressed tube to compress and fix
the lead, thereby achieving the purpose of lead connection.

1. Tools and materials needed: – electric hydraulic plier – matching pressing dies – rasp – wire cutters – cold-pressed tubes – copper strands – crepe paper (yellow color) – crepe paper (black color) – white cloth tape – electric constant temperature drying oven.

2. Operation procedure
2.1 Place the crepe paper (yellow and black) and white cloth tape in the electric constant temperature
drying oven at 105°C for 3 hours.

2.2 According to the cross-sectional area of the wire to be pressed, select the appropriate pressing die
and cold-pressed tube, connect the high-pressure hose between the hydraulic pump and the hydraulic
plier, place the die in the hydraulic plier’s groove, neatly cut one end of the wire to be
pressed with wire cutters and insert it into the cold-pressed tube about halfway.

After the lead wire is inserted into the cold-pressed tube if the gap between the wire and the
cold-pressed tube is large, it is necessary to add some thin copper wire between the gaps to make the
cold-pressed tube and the wire firmly contact after pressing. Still, the area of the original wire should
account for more than 60% of the total cross-sectional area of the wire.
Put the cold-pressed tube with the inserted wire into the die groove, adjust the cold-pressed tube so
that the part to be crimped is within the crimping range of the die, and then perform hydraulic
pressure, and hydraulic pressure on the other end according to the above steps.
After the cold crimping is completed, use a rasp to grind the edges and corners of the cold-pressed
tube surface.

2.3 After the cold pressing is completed, the bare copper wire must be wrapped. First, wrap the cold
pressing tube and the bare copper wire from bottom to top with black crepe paper, then wrap them
with yellow crepe paper, and finally, glue the tail end with glue.

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