High-frequency servo drive system configured on modern high-speed thin-wall injection hot runner of YUDO and domestic automated molding equipment generates intense alternating electromagnetic field during continuous operation; irregular random close binding of adjacent thermocouple signal wire without isolation protection easily induces severe electromagnetic coupling interference and abnormal measuring fluctuation fault. Thermocouple transmits weak millivolt-level Seebeck potential signal extremely sensitive to external alternating magnetic flux; unshielded single-layer signal cable tightly attached to servo power cable or drive radiator makes alternating magnetic field continuously cut signal conductor and induce extra parasitic voltage superimposed on original effective measuring data, resulting in dozens of degrees instantaneous random temperature jump on controller display screen. Many inexperienced maintenance operators misjudge interference phenomenon as internal thermocouple short-circuit or core wire aging damage and replace intact sensors blindly, leading to unnecessary spare part waste and wasted production debugging time.
Single-shield ordinary thermocouple cannot completely isolate high-density high-frequency servo electromagnetic radiation under wiring spacing less than specified safety distance; only double independent full-shield paired thermocouple cable can effectively shield stray magnetic field invasion under harsh electromagnetic environment. Standard wiring specification stipulates thermocouple signal harness must maintain more than 5cm safe separation gap from all servo power lines and drive installation area, adopting fixed plastic isolation buckle to separate signal cable and high-current power cable into independent isolated wiring trough respectively during layout construction. For compact narrow mold internal space unable to realize wide-distance separation temporarily, wrap thermocouple outer wire with additional independent metal shielding sleeve to strengthen anti-interference capability effectively.
Monthly regular equipment inspection rearranges messy irregular bound wiring near servo drive position according to standardized layout requirement, rectifying leftover nonstandard wiring from previous random rush maintenance operation and eliminating electromagnetic interference source fundamentally to stabilize long-term hot runner temperature control precision of high-speed automated production line.
