What should high frequency transformer pay attention to when using three layers of insulation line? Is it OK to use casing instead of three layers of insulated wire?

author: MagTop
transformer manufacturer,high-frequency transformers
High frequency transformer triple insulated wire is a kind of high performance insulated wire, which has three insulation layers, the middle is the core wire, the first layer is golden polyamine film, its thickness is several microns, but can accept 3KV pulse high voltage, the second layer is highly insulating spray paint coating, the third layer is clear glass fiber layer, the third layer is the high insulation.
The total thickness of the insulation layer is only 20-100um, its advantages are high insulation strength, arbitrary between the two layers can accept 3000V AC safety voltage, the current density is large.

The use of three layers of insulation wire should pay attention to the following points:

1. Special equipment such as three-layer insulated wire film stripping machine and adjustable film stripping machine should be selected when peeling the coated film.
It is characterized by melting the coating and peeling operation at the same time, so it will not damage the wire.
If the use of ordinary wire film stripping machine to strip the insulation film, the wire may be stretched thin or even broken.

2. There are two kinds of devices for welding three-layer insulated wires.
The other is a static filler metal groove, suitable for welding three layers of insulated wire below 4.0mm.
During soft brazing, the welding operation can be completed in a short time by moving horizontally in the filler metal tank and stirring the coil skeleton.
Another welding device is an air cooled jet filler metal tank, which can weld multiple coil frames together and is suitable for mass production.

3. The storage condition of the three-layer insulated cable is that the ambient temperature is -25 to 30 degrees Celsius, the relative humidity is 5% to 75%, and the storage period is one year.
It is forbidden to store the three-layer insulated wire in the environment of high temperature, high humidity, direct sunlight and dust.
For the three-layer insulated wire beyond the storage period, it is necessary to do the insulation breakdown voltage, voltage resistance and winding test again before it can be used.

4. Wire winding should pay attention to the following precautions: three layers of insulation wire is strengthened by film insulation.
If the membrane due to mechanical stress or thermal stress caused serious deformation, damage, safety standards can not be ensured;
There shall be no burr on the transformer skeleton, the corner part of the contact wire should be greasy (forming chamfering), the inner diameter of the outlet mouth should be 2~3 times the outer diameter of the wire;
The end of the cut wire is very sharp. Do not approach the wire coating.

Because of the small skeleton of some high-frequency transformers, the technicians of the transformer manufacturers advocate replacing a group of three-layer insulated wires with bushing. Is it possible that the volume of the bushing will be smaller than that of the three-layer insulated wires?

Answer 1:
When there is no three-layer insulated wire, enamelled wire is used for the first stage, but a retaining wall is needed to satisfy the safety distance of 6.4mm. Later, there is a three-layer insulated wire, and the three-layer insulated wire can withstand 4000V. Therefore, three-layer insulation is used for the eliminated retaining wall, and the bushing only acts as the barrier.
That's not true.

Answer 2: The claim of the transformer manufacturer should only be the inlet and outlet bushing.
Enameled wire will be much thinner all day long.
In fact, mainly depends on your safety requirements are requirements, can be replaced with enameled wire, in and out of the line and edge to do a good barrier.
That's okay.

Answer 3: The volume of the casing is of course much larger. The ideal solution: After you wrap one set of tubes, wrap the other set of tubes with yellow insulating wax (or electrical insulation tape after one loop), which saves much more volume than if you used the casing.
I personally think: the best use of yellow wax thick, because of its high temperature resistance, high pressure, insulation performance is very good, the temperature within 80° continuous 24 hours normal use, no problem, and the use of electrical insulation tape, high temperature resistance is not, very simple broken.