Wiring a YUDO hot runner system must adhere to three core principles: "separate power and signal lines," "ground the shielding layer at a single point," and "route lines to be short, straight, and away from interference sources." The key steps involve planning the routing path, laying power and temperature control cables, connecting terminal blocks to the temperature control unit, implementing shielding and grounding measures, and finally, conducting insulation and continuity tests.
I. Pre-wiring Preparation and Planning
1. Confirm System Configuration
Verify the number of heating circuits, the number of thermocouple points, and their corresponding designations (e.g., H1–H8, T1–T8) on the YUDO hot runner manifold.
Confirm that the temperature controller model (e.g., YR3000 series) matches the required number of channels, and prepare the corresponding quantity of double-shielded cables (Recommended specifications: 2.5 mm² for power lines; 0.75 mm² twisted-pair shielded cable for signal lines).
2. Plan the Routing Path
Power lines (heating outputs) and signal lines (thermocouples) must be routed in separate cable trays or conduits, maintaining a separation distance of at least 30 cm.
Avoid routing cables near the output paths of high-power equipment (such as servo drives, frequency converters, or welding machines) to minimize the risk of electromagnetic coupling.
Prioritize routing signal lines to cross power lines perpendicularly; avoid running them parallel to power lines over long distances.
II. Cable Laying and Connection
1. Laying Power Lines (Heating Outputs)
Route cables from the heating output terminals of the temperature control unit through cable trays or metal conduits to the junction box located on the mold side.
Route each heating circuit independently to avoid parallel connections, ensuring that the cable gauge is sufficient to handle the current load (typically ≥ 2.5 mm²).
Leave sufficient slack at both ends of the cables (recommended: ≥ 30 cm) to facilitate future maintenance.
2. Laying Temperature Control Signal Lines (Thermocouples)
Use dedicated, double-shielded thermocouple extension wires (Type K or Type J, matching the specific thermocouple type). Each thermocouple wire must be routed independently through its own conduit, or a multi-core shielded cable must be used; sharing a common outer sheath with power cables is strictly prohibited.
Maintain line continuity with no splices; if splicing is unavoidable, use specialized welding techniques or dedicated terminals, and ensure proper restoration of the shielding layer.
3. Connecting to the Mold-Side Terminal Block
Connect the power cables and thermocouple wires to the corresponding numbered pins on the mold's aviation connectors or terminal blocks.
Tighten the terminal screws securely to ensure low contact resistance, thereby preventing overheating or poor signal contact.
Install a metal liner inside the junction box and ground it to enhance local shielding effectiveness.
4. Connecting to the Temperature Control Unit
Connect the power cables to the "Heating Output" terminals (OUT+ / OUT-) on the temperature control unit.
Connect the thermocouple wires to the "TC IN" terminals; ensure that the positive and negative polarities are not reversed.
YUDO temperature controllers typically support automatic recognition, but it is still necessary to verify the channel configuration settings.
III. Shielding and Grounding (Critical Steps for Interference Suppression)
1. Shielding Layer Management
For Dual-Layer Shielded Cables:
Inner Shielding Layer: Connect to the "Signal Ground" (SG) terminal at the temperature control unit side; leave the mold-side end floating (unconnected) or insulate it.
Outer Shielding Layer: Connect to the "Protective Ground" (PG) terminal at the temperature control unit side to facilitate the discharge of high-frequency interference.
It is strictly prohibited to ground both ends of the shielding layer simultaneously, as this creates a ground loop and amplifies common-mode interference.
2. System Grounding
All equipment (temperature control unit, mold, and injection molding machine) must be connected to a unified, single-point equipotential grounding busbar.
Use a bare copper cable with a cross-sectional area of ≥6 mm² for the grounding wire; ensure the routing path is short and direct, and verify via measurement that the actual grounding resistance is <1 Ω.
Ensure that the Functional Ground (SG) and Protective Ground (PG) converge at a single point before connecting to the main ground, thereby maintaining proper FG/PG separation.
IV. Inspection and Testing
1. Insulation Testing
Use a megohmmeter to measure:
Insulation resistance of heating circuits to ground: >10 MΩ
Insulation resistance of thermocouple wires to ground: >50 MΩ
If any leakage is detected, immediately troubleshoot for damaged cables or wiring errors.
2. Continuity Testing
Use a multimeter to verify that every heating circuit and thermocouple channel exhibits proper continuity and is free of short circuits.
Verify the consistency of component numbering to prevent "misconnections" or "cross-connections."
3. Power-On Test Run
Upon initial power-up, configure the system for a "low-power test run" (e.g., at 30% power) and monitor the temperature response of each heating zone.
Observe for any alarms or abnormal fluctuations, and confirm that communication is stable.
YUDO Official Recommendation: In high-reliability applications-such as the automotive and medical sectors-an "EMC pre-test" should be conducted after wiring is complete to ensure the system complies with the IEC 61000-4-4 standard.
