Cara Menentukan Apakah Pemanas Hot Runner Bocor

I. Penilaian Awal Penampilan dan Fenomena Fenomena Abnormal Pemeriksaan: Saat pemanas dinyalakan, termostat sering melaporkan arus berlebih, dan pemutus sirkuit pelindung kebocoran trip secara acak. Hal ini disertai dengan fluktuasi yang tidak menentu dalam pembacaan suhu termokopel, yang sangat menunjukkan adanya kesalahan kebocoran. Inspeksi Visual: Amati selubung pemanas untuk melihat tanda-tanda terbakar, menggembung, atau meleleh/kerusakan pada lapisan insulasi. Periksa noda hitam yang menunjukkan adanya kelembapan, oksidasi, atau rambat pada terminal kabel. II. Penilaian Akurat Isolasi Statis Offline Putuskan sepenuhnya catu daya 220V ke pemanas dan lepaskan semua kabel antara pemanas dan termostat untuk mencegah pengujian tegangan tinggi merusak sirkuit internal termostat. Gunakan megohmmeter digital 500V yang dikalibrasi. Hubungkan terminal L ke jalur input daya mana pun pada pemanas, dan terminal E ke casing logam/badan hot runner pemanas. Setelah pengujian terus menerus selama 1 menit, baca nilai resistansi isolasi: Lebih besar dari atau sama dengan 5MΩ menunjukkan tidak ada kebocoran; 0,5MΩ~5MΩ menunjukkan peringatan degradasi isolasi;<0.5MΩ directly indicates a clear leakage in the heater. 1. Perform static insulation tests on all heaters channel by channel, marking any leakage circuits with abnormal insulation resistance. 2. Accurate Judgment of Dynamic Leakage Under Live Conditions: Restore normal power supply to the heaters and heat the hot runner to its rated operating temperature of 320℃. Maintain this temperature for 2 hours to allow the system to reach stable operating conditions. Use a high-precision AC millivoltmeter, connecting one end to the equipment's reliable grounding point and the other end sequentially to the heater casing, the runner body, and the thermocouple shielding layer. If an AC voltage ≥5V is detected, dynamic leakage is identified in this circuit. Higher voltage values ​​indicate greater leakage current and a higher risk of leakage. Simultaneously observe the temperature controller data. If the sensor reading changes synchronously when leakage voltage appears, it confirms that leakage has caused crosstalk to the signal link. 3. Segmented Leakage Point Location Judgment: Individually remove the heating core body to test its insulation resistance, eliminating leakage interference from external heating cables and aviation connectors. If the heating core body insulation is qualified, segmentally test the insulation performance of the heating cables and connectors to locate leakage points where the cable insulation is damaged or the connectors are damp and oxidized. Disassemble the heater to confirm its internal condition and check for leakage paths caused by moisture in the magnesium oxide insulation layer, heating wire touching the shell, and broken ceramic lining.