Kako odrediti da li Hot Runner grijač curi

I. Preliminarni izgled i procjena fenomena Provjera abnormalne pojave: Nakon pokretanja grijača, termostat često javlja prekomjernu struju, a prekidač za zaštitu od curenja se nasumično isključuje. Ovo je praćeno nepravilnim fluktuacijama u očitavanju temperature termoelementa, što snažno ukazuje na grešku curenja. Vizuelni pregled: Promatrajte kućište grijača da li ima znakova lokaliziranog gorenja, ispupčenja ili topljenja/oštećenja izolacijskog sloja. Provjerite ima li crnih mrlja koje ukazuju na vlagu, oksidaciju ili puzanje na terminalima ožičenja. II. Tačna procjena vanmrežne statičke izolacije Potpuno isključite 220V napajanje grijača i uklonite sve žice između grijača i termostata kako biste spriječili visokonaponsko testiranje od oštećenja unutrašnjeg kola termostata. Koristite kalibrirani digitalni megoommetar od 500 V. Spojite L terminal na bilo koji ulazni vod grijača, a E terminal na metalno kućište grijača/telo vruće vode. Nakon kontinuiranog testiranja u trajanju od 1 minute, očitajte vrijednost otpora izolacije: Veća ili jednaka 5MΩ ukazuje da nema curenja; 0.5MΩ~5MΩ označava upozorenje o degradaciji izolacije;<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.