Talking about the performance of motor lead wires from actual cases
The effect of the lead on the motor
The motor lead wire is very small for a whole machine, but its role is very large. A large part of the motor is grounded and phased due to the lead wire, but how to solve this problem may be quite a lot. Motor manufacturers have a headache.
According to the current paint immersion process of motor manufacturers, many manufacturers have adopted vacuum pressure immersion paint, and a problem derived therefrom is the problem of hard and cracked stator leads after lead immersion. If there is lead immersion paint, there are two ways to dip the lead into the lead, one is the soldering position of the lead and the lead, and the other is the position of the lead end. For this reason, many motor manufacturers use a silicone rubber self-adhesive. The necessary ligation and closure of the ends of the belt were carried out to see the obvious effect.
In view of the fact that the JG wire was insulated and immersed in the crack, the lead was subjected to a comparative test of impregnating and non-impregnated simulated stator drying. The unimpregnated lead insulation did not change significantly, but after immersion The lead insulation becomes very brittle and the slightly bent insulation is completely broken. For this type of problem, the lead manufacturer should be aware of the specificity of the motor lead requirements and meet the requirements of the motor lead dip coating process.
JB/T 6213.4 standard "Motor winding lead flexible cable and cord Part 4: Continuously running conductor with a maximum temperature of 180 °C flexible cable", it is clear that the cable should be able to withstand the influence of immersion paint. The standard stipulates that after the finished cable is subjected to the specified dipping test, the insulation and the sheath shall not exhibit swelling, cracking or other damage visible in normal visual inspection, and the withstand voltage test after bending shall not be broken down.
Impulse test of motor lead cable
● Sample preparation
Three samples of about 1 meter long are taken from the finished cable, and one end is stripped of insulation for about 20 mm to expose the conductor for connection to high voltage.
(1) The sample was preheated in an oven at a predetermined temperature for 24 hours, and then taken out from the oven, and the sample was immersed in an impregnating varnish at room temperature for 2 hours for 1 hour. The sample was taken out from the dipping varnish, and dried vertically for 30 minutes, and then the sample was placed in an oven for baking. The baking temperature and baking time of the oven were specified or agreed by both the supplier and the buyer.
(2) The sample is taken out, and after the sample is cooled, a section of the sample is slowly bent by 180° on a round rod of a prescribed diameter.
(3) The bent portion of the bent U-shaped sample is immersed in water at room temperature to a depth of at least 100 mm. Then, a predetermined voltage was applied between the conductor and the water for 1 minute.
(4) When the demander does not propose the impregnating lacquer grade, the bisphenol A epoxy solventless impregnating varnish should be used, and the viscosity of the lacquer at 30±1 C is 30 seconds (coating 4 cups).
For the test parameters involved in this content, there are specific provisions in JB/T6213.1.
Reprinted from the network