Kalis Letupan Shenhai
Dalam peralatan elektrik yang dipertingkatkan keselamatan, seperti motor kalis letupan, transformer, wayar elektromagnet, dan pemberat untuk lampu pendarfluor, sebahagian termasuk belitan dalaman. Keperluan untuk belitan ini, secara mekanikal dan elektrikal, adalah lebih tinggi daripada belitan standard.
Secara amnya, wayar berpenebat yang digunakan untuk menggulung gegelung ini hendaklah berpenebat dua kali, and the coil’s rated diameter must not be less than 0.25mm.
For the enameled wire used in winding these coils, it is recommended to use GB/T6109.2-2008 “Polyester Enameled Round Copper Wire, Class 155,” GB/T 6109.5-2008 “Polyester-imide Enameled Round Copper Wire, Class 180,” GB/T 6109.6-2008 “Polyimide Enameled Round Copper Wire, Class 220,” or GB/T6109.20-2008 “Polyamide-imide Composite Polyester or Polyester-imide Enameled Round Copper Wire, Class 220.”
Selain itu, Gred 1 enameled round copper wire as specified in these standards can be used, provided it passes the relevant tests outlined in the standards.
After winding, an appropriate impregnating agent should be used to enhance the insulation properties of the windings.
The impregnation process should follow the manufacturer’s specified method, using techniques like dipping, trickling, or vacuum pressure impregnation (VPI) to fill the gaps between winding wires and ensure strong adhesion. If the impregnating agent contains solvents, the impregnation and drying should be performed twice to allow solvent evaporation.
Secara amnya, methods like spraying or coating for insulating windings are considered unreliable for peralatan elektrik kalis letupan. Adequate attention should be given to this in engineering practice.
Lebih-lebih lagi, for high-voltage windings, the impregnated windings should be treated with anti-corona paint to prevent additional hazards caused by corona discharges.
In enhanced-safety electrical devices, whether motors, electromagnetic coils, or other equipment’s coils, they should generally be equipped with suhu protection devices to prevent exceeding limit temperatures under normal operation or recognized abnormal conditions.
If a winding does not exceed the limit temperature under continuous overload (such as a motor rotor lock), or if a winding is not subject to overload (like a ballast for fluorescent lamps), then it does not require a temperature protection device.
When enhanced-safety electrical equipment is equipped with temperature protection devices, these can be installed either internally or externally. Regardless, the protection device should have the appropriate jenis kalis letupan and should be assessed in conjunction with the protected equipment.